OpenEVSE Level 2 EV Charging Station

This lab guides students through the assembly, interfacing, and testing of an OpenEVSE Level 2 Electric Vehicle Supply Equipment (EVSE) controller based on an ATmega328P microcontroller and an ESP32 Wi-Fi gateway. Working with real-world electric vehicle charging standards, students explore the analog signal generation and detection required for the SAE J1772 and IEC 61851 Control Pilot (CP) and Proximity Pilot (PP) circuits, high-voltage AC mains monitoring, continuous ground integrity monitoring (CGMI), and active ground-fault circuit interrupter (GFCI) protection using current transformers. Students assemble and verify multi-rail power supplies—including buck conversion and negative charge pump generation—and test high-current contactor relay switching, serial communication via the RAPI protocol, and connected EVSE telematics over Wi-Fi, MQTT, and OCPP.

EVSE electric vehicle supply equipment SAE J1772 IEC 61851 EV charging ATmega328P microcontroller GFCI ground fault circuit interrupter control pilot proximity pilot current transformer optoisolator charge pump power electronics ESP32 embedded systems OCPP MQTT

Uploaded by demo on 2026-09-03 · ready · Electronics · Original source ↗

Files: OpenEVSE_PLUS_README.md · OpenEVSE_PLUS_v6.5.1.brd · OpenEVSE_PLUS_v6.5.1.sch · OpenEVSE_v6.5_schematic.pdf · esp32_wifi_platformio.ini · open_evse_firmware_README.md · esp32_wifi_README.md

Readiness checks

  • complete 2026-09-03 01:25 🛡 Cybersecurity: Review before networking 100 searches · 1 pages · $0.61
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Latest report — 2026-09-03 01:25

Readiness: OpenEVSE Level 2 EV Charging Station

Verdict: Ready with caveats · 2026-09-03 · est. parts cost $73–$85 Cybersecurity — software & network: Review before networking

This is a cold check establishing the baseline pricing, availability, and lifecycle metrics for the OpenEVSE Level 2 EV Charging Station controller. All 57 BOM line items are physically procurable today without requiring PCB layout modifications. However, caveats exist requiring instructor intervention: several manufacturer part numbers are unlisted or obsolete (requiring active drop-in equivalents), an under-voltage capacitor spec must be corrected to maintain DC bias margin on the +12 V rail, and the snapshot's sample relay MPN must be corrected to the official 40 A/50 A mains contactor.

Action required

Part Problem Recommended action
HCPL-2731S (IC8) Original onsemi MPN HCPL2731SD is Obsolete (0 stock across distributors). Order active direct replacement HCPL2731SDM ($2.72, DigiKey) or HCPL-2731-300E ($4.49, DigiKey).
AZ23C5V6-7-F (D1) Diodes Inc. MPN has zero distributor stock at DigiKey and only 30 units at Arrow. Order active drop-in replacement AZ23C5V6-TP ($0.24, DigiKey).
High-Voltage Resistors, 180 kΩ 1210 (R32–R39) Sample MPN CRHV1210AF180KFKE5 is unlisted across distributors. Order active drop-in thick film 1210 resistor RC1210FR-07180KL ($0.16, DigiKey).
Ceramic Capacitors, 10 µF 0805 (C5, C6, C13, C28) Planned MPN CL21A106KOQNNNE is out of stock and rated only 16 V, failing the lab's ≥ 25 V constraint. Order 35 V rated 0805 ceramic capacitor C2012X5R1V106K085AC ($0.48, DigiKey).
Tantalum Capacitor, 10 µF 0603 (C17) Sample MPN TLNK106M006R1500 is unlisted across distributors. Order drop-in 0603 ceramic capacitor CL10A106KP8NNNC ($0.21, DigiKey).
Power Inductor, 3.3 µH NR5040 (L2) Original MPN NR5040T3R3N is marked Obsolete by Taiyo Yuden. Order active manufacturer-recommended successor LCXND5050YAL3R3NMG ($0.40, DigiKey).
Crystal Resonator, 16 MHz (Q1) Planned MPN NX3225SA-16.000M-STD-CRS-2 is out of stock. Order specified alternative ABM8G-16.000MHZ-18-D2Y-T ($0.49, DigiKey).
AC Mains Fuse, 1.6 A (F1) Planned MPN 0679L1600-01 unlisted; BELFUSE1A footprint is a 5.08 mm through-hole box. Order active 350 VAC radial box successor 0697H1600-05 ($0.54, DigiKey) or in-stock legacy RST 1.6-BULK ($0.57, DigiKey).
External AC Contactor Snapshot sample MPN 899-1CH-F-C-12VDC is an inappropriate 10 A subminiature relay and out of stock. Order the official UL-listed 40 A inductive / 50 A resistive contactor with 208–240 VAC coil, Packard C240C ($24.99, OpenEVSE Store).

Cybersecurity — software & network

Review before networking — The ESP32 WiFi gateway firmware exposes network services including an HTTP interface, WebSocket stream, and OTA update endpoint, but its version and dependencies could not be verified against vulnerability databases.

Component Version How known Support status
open_evse 9.0.0 inferred (inferred from documentation recommendation in lab snapshot) —
openevse_esp32_firmware not determined not determined —
espressif32 7.1.0 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
platform-espressif32 55.03.311 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
esp-idf 5.5.4 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
bblanchon/ArduinoJson 6.20.1 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
jeremypoulter/ArduinoMongoose ca0a817de014cf4ab1833b32383532366fca10d7 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
jeremypoulter/Micro Debug 0.0.5 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
jeremypoulter/ConfigJson 0.0.6 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
OpenEVSE/OpenEVSE_Lib v0.0.20 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
jeremypoulter/ESPAL 0.0.7 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
jeremypoulter/StreamSpy 0.0.2 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
jeremypoulter/MicroTasks 0.0.4 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
matth-x/MicroOcpp 1.2.0 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
matth-x/MicroOcppMongoose 1.2.0 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
adafruit/Adafruit MCP9808 Library 2.0.2 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
adafruit/Adafruit NeoPixel 1.15.5 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
kitesurfer1404/WS2812FX 1.4.7 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
rar/esp_tsdb 2.4.3 inferred (inferred from snapshot reference to esp32_wifi_platformio.ini) —
bodmer/TFT_eSPI not determined unpinned (snapshot indicates caret range ^2.5.43 in esp32_wifi_platformio.ini) —
bitbank2/PNGdec not determined unpinned (snapshot indicates caret range ^1.1.5 in esp32_wifi_platformio.ini) —
lvgl/lvgl not determined unpinned (snapshot indicates caret range ^8.3.9 in esp32_wifi_platformio.ini) —

No security findings — every dependency checked this run came back clean.

What this means for your lab

Anyone on the same local network or Wi-Fi segment can access the charging station's web server, live WebSocket telemetry stream, and over-the-air firmware update endpoint, which could allow unauthorized users to monitor charging sessions or modify device configuration. Because the ESP32 gateway firmware version and third-party libraries could not be checked against vulnerability databases, their security posture cannot be verified. Instructors should place the charging station on an isolated lab network or dedicated VLAN rather than an open campus network, complete the initial setup wizard to configure strong administrative credentials, and consult campus IT before connecting the hardware.

Not checked

  • open_evse: no advisory database for the ecosystem (vendor AVR firmware repository)
  • openevse_esp32_firmware: version not determined in project documentation
  • espressif32: lookup failed (product_not_found on endoflife.date)
  • platform-espressif32: lookup failed (product_not_found on endoflife.date)
  • esp-idf: lookup failed (product_not_found on endoflife.date)
  • PlatformIO pinned libraries: no vulnerability lookup performed during session
  • PlatformIO author and git-pinned libraries: no advisory database for author libraries or git commit references
  • PlatformIO unpinned libraries (TFT_eSPI, PNGdec, lvgl): unpinned caret version ranges in manifest
  • espressif32 7.1.0: support status: endoflife.date has no such product
  • platform-espressif32 55.03.311: support status: endoflife.date has no such product
  • esp-idf 5.5.4: support status: endoflife.date has no such product

Parts

Microcontroller and Logic ICs

Part Spec/Package Status Stock Price Source
ATmega328P-AU 8-bit Microcontroller 32 KB Flash, 16 MHz, TQFP-32 Readily available 29,655 $2.66 DigiKey
AP63203 Synchronous Buck Converter IC 2 A, 5.0 V out, TSOT-26 Readily available 167 $0.95 DigiKey
TC1044S Inverting Charge Pump Inverting charge pump, SOIC-8 Readily available (via orderable MPN) 1,242 $1.26 DigiKey
LMV358 Rail-to-Rail Dual Op-Amp Rail-to-rail output, 5 V, SOIC-8 Readily available 7,044 $0.45 DigiKey
LM358 Dual General-Purpose Op-Amp ±12 V supply, SOIC-8 Readily available 103,684 $0.26 DigiKey
AQH2223 Solid-State Relay / AC Driver 600 V, 0.9 A, non-zero cross, 8-SMD Readily available 2,545 $1.78 Mouser
HCPL-2731S Dual Darlington Optocoupler CTR ≥ 400%, 5 kV isolation, 8-SMD Obsolete (use drop-in substitute) 4,495 $2.72 DigiKey

Discrete Semiconductors

Part Spec/Package Status Stock Price Source
MMBT2222A NPN Transistor 40 V, 600 mA, SOT-23-3 Readily available 547,932 $0.17 DigiKey
AZ23C5V6-7-F Dual Zener Diode 5.6 V common cathode, SOT-23-3 Low stock (use drop-in substitute) 10,352 $0.24 DigiKey
AZ23C2V7-7-F Dual Zener Diode 2.7 V common cathode, SOT-23-3 Readily available 619 $0.41 DigiKey
1N4148 Fast Switching Diode 100 V, 150 mA, SOD-123 Readily available 1,283,914 $0.18 DigiKey
1N4004 Rectifier Diode 400 V, 1 A, SMA (DO-214AC) Readily available 484,759 $0.26 DigiKey
P6SMB16CA Bidirectional TVS Diode 600 W, 13.6 V standoff, SMB Readily available 1,657 $0.61 DigiKey
MOV Surge Suppressor 275–300 VAC, 430 V typ, 10 mm radial Readily available 51,379 $0.24 DigiKey

Passives: Resistors

Part Spec/Package Status Stock Price Source
Current Sense Resistor, 2.0 Ω 2.0 Ω, 1%, 0.125 W, 0805 Readily available 13,114 $0.12 DigiKey
Resistor, 22 Ω 22 Ω, 5%, 0.25 W, 1206 Readily available 26,651 $0.10 DigiKey
Resistor, 100 Ω 100 Ω, 1%, 0.125 W, 0805 Readily available 111,241 $0.10 DigiKey
Resistor, 330 Ω 330 Ω, 5%, 0.125 W, 0805 Readily available 16,291 $0.10 DigiKey
Precision Pilot Resistor, 422 Ω 422 Ω, 1%, 0.125 W, 0805 Readily available 36,528 $0.10 DigiKey
Resistor, 820 Ω 820 Ω, 5%, 0.125 W, 0805 Readily available 13,385 $0.10 DigiKey
Resistor, 1 kΩ 1 kΩ, 1%, 0.125 W, 0805 Readily available 1,006,526 $0.10 DigiKey
Resistor, 10 kΩ 10 kΩ, 1%, 0.125 W, 0805 Readily available 1,168,650 $0.10 DigiKey
Resistor, 20 kΩ 20 kΩ, 1%, 0.125 W, 0805 Readily available 313,926 $0.10 DigiKey
Resistor, 56 kΩ 56 kΩ, 1%, 0.125 W, 0805 Readily available 44,846 $0.10 DigiKey
Resistor, 100 kΩ 100 kΩ, 1%, 0.125 W, 0805 Readily available 578,290 $0.10 DigiKey
High-Voltage Sense Resistor, 180 kΩ 180 kΩ, 1%, 0.5 W, 200 V, 1210 Unlisted (use drop-in substitute) 4,921 $0.16 DigiKey
Resistor, 200 kΩ 200 kΩ, 1%, 0.125 W, 0805 Readily available 60,123 $0.10 DigiKey

Passives: Capacitors

Part Spec/Package Status Stock Price Source
Ceramic Capacitor, 22 pF 22 pF, 50 V, C0G, 0805 Readily available 31,058 $0.10 DigiKey
Ceramic Bypass Capacitor, 0.1 µF 0.1 µF, 50 V, X7R, 0805 Readily available 5,566,409 $0.16 DigiKey
Ceramic Capacitor, 1 µF 1 µF, 25 V, X7R, 0805 Readily available 465,414 $0.16 DigiKey
Ceramic Capacitor, 10 µF 10 µF, ≥ 25 V (35 V), X5R, 0805 Spec mismatch (use upgrade substitute) 428,331 $0.48 DigiKey
Polarized Capacitor, 10 µF 10 µF, 16 V, EIA 3216-18 (Case A) Readily available 190,789 $0.58 DigiKey
Tantalum Capacitor, 10 µF 10 µF, ≥ 6.3 V, 0603 Unlisted (use drop-in substitute) 685 $0.21 DigiKey

Inductors, Resonator, and Protection

Part Spec/Package Status Stock Price Source
Power Inductor, 3.3 µH 3.3 µH, ISAT ≥ 2.5 A, 5×5 mm SMD Obsolete (use manufacturer successor) 2,896 $0.40 DigiKey
Ferrite Bead, 330 Ω @ 100 MHz 330 Ω, 1.5 A, 0805 Readily available 322,558 $0.11 DigiKey
Crystal Resonator, 16.000 MHz 16.000 MHz, 18 pF, 3.2×2.5 mm 4-SMD Planned MPN OOS (use drop-in alternate) 21,032 $0.49 DigiKey
AC Mains Input Fuse, 1.6 A 1.6 A, 350 VAC, radial box 5.08 mm pitch Planned MPN unlisted (use active successor) 502 $0.54 DigiKey
AC/DC Power Supply Module, 10 W, 12 V 85–305 VAC in, 12 VDC 0.85 A out, 4-pin Readily available 7,994 $7.40 DigiKey

Connectors, Headers, and Test Points

Part Spec/Package Status Stock Price Source
AC Input & Relay Terminal Header, 6-pin 3.96 mm pitch, JST VH 6-pin through-hole Readily available 11,402 $0.34 DigiKey
Current Measurement CT Header, 2-pin 2.54 mm pitch, Molex KK 254 2-pin Readily available 87,682 $0.18 DigiKey
GFCI CT Header, 4-pin 2.54 mm pitch, Molex KK 254 4-pin Readily available 55,426 $0.28 DigiKey
DC Relay Driver Output Header, 3-pin 2.54 mm pitch, Molex KK 254 3-pin Readily available 114,189 $0.23 DigiKey
Serial / FTDI Gateway Header, JST PH 6-pin 2.00 mm pitch, JST PH 6-pin vertical Readily available 29,763 $0.28 DigiKey
I2C Display Header, JST PH 4-pin 2.00 mm pitch, JST PH 4-pin vertical Readily available 36,565 $0.20 DigiKey
J1772 Control Signal Header, 6-pin 2.54 mm pitch, Molex KK 254 6-pin Readily available 12,197 $0.36 DigiKey
Pilot / Proximity Screw Terminal Block, 2-pos 5.0 mm pitch, 2-position through-hole Readily available 7,806 $0.38 DigiKey
AVR ISP Header, 2×3 (6-pin) 2.54 mm pitch, dual-row male header Readily available 29,202 $0.60 DigiKey
Earth Ground Test / Solder Pads Through-hole test point loop (or bare pad) Readily available 377,642 $0.27 DigiKey

PCB Mechanical and Trace Jumpers

Part Spec/Package Status Stock Price Source
Solder Jumpers / Trace Bridges PCB copper trace feature Readily available — — Fabricated on PCB
Optical Fiducials PCB copper feature with mask opening Readily available — — Fabricated on PCB
Mechanical Mounting Holes 3.2 mm non-plated/plated drill holes Readily available — — Fabricated on PCB

External Parts Specified in Documents and Schematics

Part Spec/Package Status Stock Price Source
Ground Fault CT Coil 1000:1, self-test primary loop, in-line Readily available 2,473 $14.85 DigiKey
Current Measurement CT Coil 1000:1, 100 A rating, wire leads Readily available 168 $15.44 DigiKey
AC Input Harness Housing JST VH 6-position 3.96 mm housing Readily available 38,335 $0.17 DigiKey
AC Input Harness Crimp Contacts JST SVH crimp pin, 20–16 AWG Readily available 1,511,736 $0.0552 DigiKey
JST PH 4-Pin and 6-Pin Wiring Harnesses 2.00 mm female-female pre-crimped leads Readily available In stock $3.23 Pololu / Retail
External AC Contactor 40 A inductive / 50 A resistive, 208–240 VAC coil Readily available In stock $24.99 OpenEVSE Store

Substitutes

For part Substitute Differences Verified Judgment
HCPL-2731S (HCPL2731SD) HCPL2731SDM 8-SMD Gull Wing; isolation rated 5000 Vrms (exceeds original 2500 Vrms / 3750 Vrms); CTR min 500% at 1.6 mA (exceeds ≥ 400%). Direct modern tooling revision. package + lead spacing, CTR, isolation Acceptable drop-in replacement.
AZ23C5V6-7-F AZ23C5V6-TP Identical SOT-23-3 dual common-cathode array; nominal Vz = 5.6 V, 300 mW power dissipation. package, zener voltage, power rating Acceptable drop-in replacement.
High-Voltage Resistors, 180 kΩ 1210 (CRHV1210AF180KFKE5) RC1210FR-07180KL 1210 thick film resistor; 180 kΩ, ±1%, 0.5 W; limiting voltage 200 V (operates in series pairs across 277 VAC mains dropping < 200 V peak per part). package, resistance, power rating Acceptable drop-in replacement.
Ceramic Capacitors, 10 µF 0805 (CL21A106KOQNNNE) C2012X5R1V106K085AC 0805 footprint; rated 35 V (exceeds 16 V rating of planned part and satisfies ≥ 25 V lab requirement for +12 V rail DC bias). Lifecycle is Not For New Designs, but 428k+ stocked. package, capacitance, voltage Acceptable drop-in upgrade.
Tantalum Capacitor, 10 µF 0603 (TLNK106M006R1500) CL10A106KP8NNNC 0603 footprint; multi-layer ceramic rated 10 V (exceeds 6.3 V constraint); non-polarized dielectric prevents reverse polarity installation errors. package, capacitance, voltage rating Acceptable drop-in replacement.
Power Inductor, 3.3 µH (NR5040T3R3N) LCXND5050YAL3R3NMG 4.9 mm × 4.9 mm × 4.0 mm SMD; 3.3 µH; saturation current ISAT = 4.0 A (exceeds 2.5 A requirement); DCR = 27 mΩ (lower than original 35.1 mΩ). package dimensions, inductance, saturation current, DCR Acceptable drop-in replacement.
Crystal Resonator, 16 MHz (NX3225SA-16.000M-STD-CRS-2) ABM8G-16.000MHZ-18-D2Y-T Standard 3.2 mm × 2.5 mm 4-SMD package; 16.000 MHz fundamental; load capacitance 18 pF (matches C1/C2 22 pF load network). Specified directly in snapshot. package, frequency, load capacitance Acceptable drop-in replacement.
AC Mains Input Fuse, 1.6 A (0679L1600-01) 0697H1600-05 Radial box package (8.35 mm × 4.0 mm, 5.08 mm lead pitch) matching BELFUSE1A footprint; 1.6 A time-lag; rated 350 VAC (exceeds 277 VAC mains requirement). package, current rating, voltage rating Acceptable drop-in replacement.
External AC Contactor (899-1CH-F-C-12VDC) Packard C240C Heavy-duty chassis mount contactor; contacts rated 40 A inductive / 50 A resistive continuous, 600 VAC; 208–240 VAC coil driven directly by onboard AQH2223 triac SSR. continuous current rating, contact voltage, coil voltage, OpenEVSE controller compatibility Acceptable primary contactor.

Verify all substitutes against manufacturer datasheets and board mechanical dimensions before ordering.

Other dependencies

  • PCB Fabrication: 2-layer FR-4 board, 91.14 mm × 51.27 mm. Requires isolation routing slot separating high-voltage AC mains from low-voltage logic (meeting UL/IEC creepage ≥ 6.4 mm and clearance ≥ 3.2 mm for 277 VAC operation). Ready for fabrication.
  • Hardware Design Repository: https://github.com/OpenEVSE/OpenEVSE_PLUS — active repository.
  • Controller Firmware Repository: https://github.com/OpenEVSE/open_evse — active repository.
  • ESP32 Gateway Firmware Repository: https://github.com/OpenEVSE/ESP32_WiFi_V4.x — active repository.
  • Hardware Store / Accessories: https://store.openevse.com — active and verified.
  • HTTP API Documentation: https://openevse.stoplight.io/docs/openevse-wifi-v4/ — active.
  • Emoncms Service Integration: https://emoncms.org — active link.

Watch list

  • Taiyo Yuden NR5040T3R3N inductor: The original series is Obsolete. While distributor inventory remains, instructors should migrate documentation to the active manufacturer replacement LCXND5050YAL3R3NMG.
  • Bel Fuse subminiature fuses (RST 1.6-BULK): The legacy RST series is Obsolete despite high remaining distributor stock (>97k units). Future procurement should specify the active 350 VAC successor 0697H1600-05 or 0697H1600-01.
  • TDK C2012X5R1V106K085AC capacitor: Marked Not For New Designs by TDK. Hundreds of thousands remain in distributor stock, but instructors should track active alternatives (such as Kyocera AVX KGM21AR51E106KU).
  • CR Magnetics Current Transformers (CR8450-1000): Stock at primary distributors is modest (168 units at DigiKey). Reorder lead times should be monitored for larger lab classes.
Snapshot What the lab depended on when it was uploaded — the baseline the readiness checks research against.

This lab builds the OpenEVSE PLUS v6.5 / v6.5.1 Level 2 Electric Vehicle Supply Equipment (EVSE) Controller, an open-source EV charging station controller adhering to SAE J1772 and IEC 61851 charging standards. The controller hardware operates directly from AC line mains (100–277 VAC nominal, 50/60 Hz) and incorporates an onboard Mean Well encapsulated AC/DC switching power supply delivering a primary +12 VDC internal power rail (rated at 10 W). The +12 VDC rail powers external contactor/relay driver circuitry, feeds an onboard Diodes Inc. AP63203 buck regulator that generates the regulated +5 VDC system logic rail, and supplies a TC1044S switched-capacitor inverting charge pump that produces a -12 VDC rail for the bipolar J1772 Control Pilot (±12 V square-wave) analog circuit. Safety and control functions are executed by an 8-bit Atmel/Microchip ATmega328P microcontroller running at 16 MHz (5 V logic), featuring hardware-interrupted active GFCI sensing, continuous ground integrity monitoring (CGMI) via dual Darlington optocouplers, stuck relay contact detection, pilot PWM generation, and high-speed UART communication (115200 baud) with an auxiliary ESP32 Wi-Fi gateway module.

Bill of Materials

Microcontroller and Logic ICs

  • ATmega328P-AU 8-bit Microcontroller

    • Identity: Microchip / Atmel ATMEGA328P-AU (schematic device entry also references ATMEGA8-16AU / ATMEGA328P-AU; board value is ATMEGA328P-AU).
    • Quantity: 1 (IC2).
    • Footprint / Package: 32-lead Thin Quad Flat Package, TQFP-32 (TQFP32-08, 7 mm × 7 mm body, 0.8 mm pitch).
    • Electrical constraints: Operating voltage 5.0 VDC (powered from the +5V rail); runs at 16 MHz via external crystal Q1. Memory: 32 KB Flash, 2 KB SRAM, 1 KB EEPROM.
    • Substitution latitude: Must be ATmega328P in TQFP-32 package. ATmega8 or ATmega168 will not have adequate flash memory for modern OpenEVSE firmware releases (v7.x–v9.x requires >28 KB).
    • Operated control: No.
    • Sourcing plan: distributor lookup: ATMEGA328P-AU

  • AP63203 Synchronous Buck Converter IC

    • Identity: Diodes Incorporated AP63203WU-7 (SparkFun PROD_ID: VREG-15244).
    • Quantity: 1 (U1).
    • Footprint / Package: SOT-23-6 (TSOT26 / SOT-26).
    • Electrical constraints: 2 A continuous output current, 3.8 V to 32 V wide input voltage range (operates from +12 VDC bus), fixed 5.0 V output voltage, 1.1 MHz switching frequency with integrated high-side and low-side power MOSFETs.
    • Substitution latitude: Must be pin-compatible and match the fixed 5.0 V output configuration and input voltage tolerance (≥16 V rating). Pinout: Pin 1 = CB, Pin 2 = GND, Pin 3 = FB/VOUT, Pin 4 = EN, Pin 5 = VIN, Pin 6 = SW.
    • Operated control: No.
    • Sourcing plan: distributor lookup: AP63203WU-7

  • TC1044S Switched-Capacitor Inverting Charge Pump

    • Identity: Microchip TC1044SEPA / TC1044SOA (device marked TC1044S).
    • Quantity: 1 (IC4).
    • Footprint / Package: SOIC-8 narrow (SO08, 150 mil width, 1.27 mm pitch).
    • Electrical constraints: Input supply voltage +12 VDC, outputs an inverted -12 VDC rail. Operating supply range must extend up to 12.6 V minimum (TC1044S is rated up to 12 V typical, 12.5 V absolute max; ICL7660S / MAX1044 compatible). Pin 1 (BOOST) boosts oscillator frequency from 10 kHz to 45 kHz.
    • Substitution latitude: Must accept +12 V input without breakdown; standard 5 V charge pumps (e.g. TC7660) will be destroyed by 12 V. Pin-compatible replacements include Intersil/Renesas ICL7660SIBAZ or Maxim MAX1044ESA+.
    • Operated control: No.
    • Sourcing plan: distributor lookup: TC1044SOA

  • LMV358 Rail-to-Rail Dual Operational Amplifier

    • Identity: Texas Instruments / STMicroelectronics LMV358IDR (SparkFun PROD_ID: IC-09657).
    • Quantity: 1 (IC1).
    • Footprint / Package: SOIC-8 narrow (SO08, 150 mil width).
    • Electrical constraints: Supply voltage 5.0 VDC (single rail). Used in the analog signal conditioning and peak detection circuitry for the ground-fault (GFCI) current transformer input. Rail-to-rail output swing is essential for reading by the ATmega328P ADC pins.
    • Substitution latitude: Pin-compatible standard dual rail-to-rail I/O 5 V op-amps (e.g., MCP6002, LMV358A). Standard LM358 cannot be used here because its output does not swing to the positive rail on a 5 V supply.
    • Operated control: No.
    • Sourcing plan: distributor lookup: LMV358IDR

  • LM358 Dual General-Purpose Operational Amplifier

    • Identity: Texas Instruments LM358DR / STMicroelectronics LM358DT.
    • Quantity: 1 (IC3).
    • Footprint / Package: SOIC-8 narrow (SO08, 150 mil width).
    • Electrical constraints: Operates from split supplies (+12 V and -12 V) or single +12 V rail to drive and buffer the J1772 Control Pilot square wave (-12 V to +12 V).
    • Substitution latitude: Any dual op-amp capable of ±12 V (24 V total) supply operation with pin-compatible standard dual op-amp pinout (Pin 1: Out A, Pin 2: In A-, Pin 3: In A+, Pin 4: V-, Pin 5: In B+, Pin 6: In B-, Pin 7: Out B, Pin 8: V+).
    • Operated control: No.
    • Sourcing plan: distributor lookup: LM358DR

  • AQH2223 Solid-State Relay / AC Optocoupler Triac Driver

    • Identity: Panasonic AQH2223 (AQH2223AX / AQH2223AZ).
    • Quantity: 1 (IC7).
    • Footprint / Package: 8-pin Single In-Line / Dual In-Line surface mount (SIL8 / DIP8 gullwing).
    • Electrical constraints: Solid-state relay, non-zero crossing (random-fire) AC triac driver. Off-state blocking voltage 600 V, RMS on-state current 0.9 A, input LED forward current 10–20 mA (driven via transistor Q2 from MCU pin).
    • Substitution latitude: AQH2223A or AQH3223A. Non-zero crossing is required to trigger AC contactors reliably.
    • Operated control: No.
    • Sourcing plan: distributor lookup: AQH2223AZ

  • HCPL-2731S Dual-Channel Darlington Optocoupler

    • Identity: Broadcom / Avago / Fairchild HCPL-2731S (HCPL-2731-500E).
    • Quantity: 1 (IC8).
    • Footprint / Package: 8-pin DIP gullwing surface mount (SIL8-2 / SMD-8).
    • Electrical constraints: Dual-channel high-gain Darlington output optoisolator with 3750 Vrms isolation rating. Current Transfer Ratio (CTR) ≥ 400% (typically 1600% at IF = 1.6 mA). Used for continuous ground monitoring (CGMI) and AC line detect from mains voltage via high-voltage 180 kΩ dropping resistors.
    • Substitution latitude: Must maintain very high CTR at low LED currents (<2 mA) and match the 8-pin dual Darlington pinout (Fairchild/ON Semi FOD2731SD, Vishay IL250). Standard single-transistor optocouplers (e.g. PC817 or 4N35) lack sufficient CTR to detect AC line presence through the 360 kΩ – 720 kΩ input resistance.
    • Operated control: No.
    • Sourcing plan: distributor lookup: HCPL-2731SD

Discrete Semiconductors

  • MMBT2222A NPN General Purpose Switching Transistor

    • Identity: ON Semiconductor / Diodes Inc. MMBT2222A-7-F (marked 2222A).
    • Quantity: 2 (Q2, Q3).
    • Footprint / Package: SOT-23-3.
    • Electrical constraints: VCEO ≥ 40 V, IC ≥ 600 mA, hFE ≥ 100. Q2 drives the AQH2223 relay trigger; Q3 drives the DC relay output.
    • Substitution latitude: Any general-purpose NPN switching transistor with VCEO ≥ 40 V and IC ≥ 500 mA (e.g., MMBT3904 is marginal on current; MMBT2222A, 2N2222 SOT-23, or PMBT2222 is preferred).
    • Operated control: No.
    • Sourcing plan: distributor lookup: MMBT2222A-7-F

  • AZ23C5V6-7-F Dual Zener Diode (5.6 V Common Cathode)

    • Identity: Diodes Inc. AZ23C5V6-7-F.
    • Quantity: 1 (D1).
    • Footprint / Package: SOT-23-3 (Pin 1: Anode 1, Pin 2: Anode 2, Pin 3: Common Cathode).
    • Electrical constraints: Zener breakdown voltage 5.6 V (5.2 V to 6.0 V), power dissipation 300 mW. Used for ADC/analog clamp protection.
    • Substitution latitude: Any dual 5.6 V common-cathode SOT-23 Zener array (e.g., BZX84C5V6-7-F dual configuration, DZ23C5V6-7-F).
    • Operated control: No.
    • Sourcing plan: distributor lookup: AZ23C5V6-7-F

  • AZ23C2V7-7-F Dual Zener Diode (2.7 V Common Cathode)

    • Identity: Diodes Inc. AZ23C2V7-7-F.
    • Quantity: 1 (D11).
    • Footprint / Package: SOT-23-3 (Pin 1: Anode 1, Pin 2: Anode 2, Pin 3: Common Cathode).
    • Electrical constraints: Zener breakdown voltage 2.7 V (2.5 V to 2.9 V), power dissipation 300 mW. Used for analog level shifting / bias clamping.
    • Substitution latitude: Pin-compatible dual 2.7 V common-cathode Zener diode array in SOT-23 (e.g., DZ23C2V7).
    • Operated control: No.
    • Sourcing plan: distributor lookup: AZ23C2V7-7-F

  • 1N4148 Fast Switching Diode

    • Identity: Vishay / Diodes Inc. 1N4148W-7-F (1N4148).
    • Quantity: 6 (D2, D3, D4, D5, D6, D12).
    • Footprint / Package: SOD-123.
    • Electrical constraints: VRRM ≥ 100 V, IF ≥ 150 mA, trr ≤ 4 ns.
    • Substitution latitude: Any standard fast switching diode in SOD-123 (e.g., 1N4148W, 1N4448W).
    • Operated control: No.
    • Sourcing plan: distributor lookup: 1N4148W-7-F

  • 1N4004 General Purpose Rectifier Diode

    • Identity: Diodes Inc. / Vishay S1G-13-F / 1N4004 (labeled 1N4004 on board and schematic).
    • Quantity: 4 (D7, D8, D9, D10).
    • Footprint / Package: SMA (DO-214AC).
    • Electrical constraints: Repetitive peak reverse voltage VRRM ≥ 400 V (typically 400 V–1000 V), average forward current IF = 1 A. Used in AC line sensing and ground monitoring rectification paths.
    • Substitution latitude: Any 1 A, 400 V to 1000 V general-purpose silicon rectifier in SMA package (e.g., S1G, S1J, S1M, or M4).
    • Operated control: No.
    • Sourcing plan: distributor lookup: S1G-13-F

  • P6SMB16CA Bidirectional Transient Voltage Suppressor (TVS)

    • Identity: Littelfuse / Vishay P6SMB16CA.
    • Quantity: 1 (TVS).
    • Footprint / Package: SMB (DO-214AA).
    • Electrical constraints: Bidirectional TVS diode. Stand-off voltage VRWM = 13.6 V, breakdown voltage VBR = 15.2 V to 16.8 V, peak pulse power 600 W (10/1000 µs waveform). Protects the J1772 Control Pilot line against vehicle ESD and transients.
    • Substitution latitude: Any bidirectional 600 W TVS diode with breakdown voltage between 15 V and 17 V in SMB package (e.g., SMBJ16CA).
    • Operated control: No.
    • Sourcing plan: distributor lookup: P6SMB16CA

  • Metal Oxide Varistor (MOV) Surge Suppressors

    • Identity: Littelfuse / Bourns MOV, 275–300 VAC continuous working voltage (schematic/board device label MOV).
    • Quantity: 4 (M1, M2, M3, M4).
    • Footprint / Package: MOV radial lead / through-hole footprint (disc diameter ~7 mm to 10 mm with 5 mm or 7.5 mm lead spacing).
    • Electrical constraints: AC voltage rating ≥ 275 VAC (for 240 VAC split-phase and 277 VAC single-phase operation), clamping voltage ~710 V at 25 A, surge energy rating ≥ 30 J.
    • Substitution latitude: Standard 7 mm to 10 mm metal oxide varistors rated for 275 VAC or 300 VAC (e.g., Littelfuse V275LA10P or V300LA10P; Bourns MOV-10D431K).
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): MOV-10D431K

Passives: Resistors

  • Current Sense Resistor, 2.0 Ω, 0805

    • Identity: Generic thick film surface mount resistor.
    • Quantity: 1 (R27).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Resistance 2.0 Ω, power rating ≥ 0.125 W, tolerance ±1%.
    • Substitution latitude: Standard 0805 thick film resistor.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRCW08052R00FKEA

  • Resistor, 22 Ω, 1206

    • Identity: Generic thick film surface mount resistor.
    • Quantity: 1 (R26).
    • Footprint / Package: 1206 (3216 metric).
    • Electrical constraints: Resistance 22 Ω, power rating ≥ 0.25 W, tolerance ±5% or ±1%.
    • Substitution latitude: Standard 1206 resistor.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRCW120622R0JNEA

  • Resistor, 100 Ω, 0805

    • Identity: Generic thick film surface mount resistor.
    • Quantity: 1 (R18).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Resistance 100 Ω, power rating ≥ 0.125 W, tolerance ±1%.
    • Substitution latitude: Standard 0805 resistor.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRCW0805100RFKEA

  • Resistors, 330 Ω, 0805

    • Identity: Generic thick film surface mount resistors.
    • Quantity: 4 (R11, R23, R24, R29).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Resistance 330 Ω, power rating ≥ 0.125 W, tolerance ±5% or ±1%.
    • Substitution latitude: Standard 0805 resistors.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRCW0805330RJNEA

  • Precision Pilot Resistor, 422 Ω 1%, 0805

    • Identity: Generic precision metal/thick film surface mount resistor.
    • Quantity: 1 (R17).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Resistance 422 Ω, tolerance ±1%, power rating ≥ 0.125 W. Used in J1772 Control Pilot analog divider circuit.
    • Substitution latitude: Must be 422 Ω ±1% to maintain standard SAE J1772 pilot voltage threshold accuracy.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRCW0805422RFKEA

  • Resistor, 820 Ω, 0805

    • Identity: Generic thick film surface mount resistor.
    • Quantity: 1 (R1).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Resistance 820 Ω, power rating ≥ 0.125 W, tolerance ±5% or ±1%.
    • Substitution latitude: Standard 0805 resistor.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRCW0805820RJNEA

  • Resistors, 1 kΩ, 0805

    • Identity: Generic thick film surface mount resistors.
    • Quantity: 3 (R3, R12, R20).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Resistance 1 kΩ, power rating ≥ 0.125 W, tolerance ±5% or ±1%.
    • Substitution latitude: Standard 0805 resistors.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRCW08051K00FKEA

  • Resistors, 10 kΩ, 0805

    • Identity: Generic thick film surface mount resistors.
    • Quantity: 6 (R2, R4, R10, R19, R22, R31).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Resistance 10 kΩ, power rating ≥ 0.125 W, tolerance ±5% or ±1%.
    • Substitution latitude: Standard 0805 resistors.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRCW080510K0FKEA

  • Resistor, 20 kΩ, 0805

    • Identity: Generic thick film surface mount resistor.
    • Quantity: 1 (R15).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Resistance 20 kΩ, power rating ≥ 0.125 W, tolerance ±1%.
    • Substitution latitude: Standard 0805 resistor.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRCW080520K0FKEA

  • Resistor, 56 kΩ, 0805

    • Identity: Generic thick film surface mount resistor.
    • Quantity: 1 (R5).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Resistance 56 kΩ, power rating ≥ 0.125 W, tolerance ±5% or ±1%.
    • Substitution latitude: Standard 0805 resistor.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRCW080556K0FKEA

  • Resistors, 100 kΩ, 0805

    • Identity: Generic thick film surface mount resistors.
    • Quantity: 7 (R6, R8, R9, R14, R16, R21, R25).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Resistance 100 kΩ, power rating ≥ 0.125 W, tolerance ±5% or ±1%.
    • Substitution latitude: Standard 0805 resistors.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRCW0805100KFKEA

  • High-Voltage Sense Resistors, 180 kΩ, 1210

    • Identity: Vishay / Panasonic High-Voltage Thick Film Resistor (SparkFun PROD_ID: RES-12374).
    • Quantity: 8 (R32, R33, R34, R35, R36, R37, R38, R39).
    • Footprint / Package: 1210 (3225 metric).
    • Electrical constraints: Resistance 180 kΩ, power rating ≥ 0.5 W, continuous working voltage rating ≥ 200 V minimum (preferably 400 V–500 V rating). Resistors sit directly across AC mains (AC1, AC2, and Earth Ground) in series pairs (forming 360 kΩ branches) for line and ground presence detection.
    • Substitution latitude: Must use 1210 size or high-voltage rated resistors. Do not substitute 0805 or lower voltage standard thick film resistors, as dielectric flashover across terminals will occur at 277 VAC mains peak voltages.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRHV1210AF180KFKE5

  • Resistor, 200 kΩ, 0805

    • Identity: Generic thick film surface mount resistor.
    • Quantity: 1 (R7).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Resistance 200 kΩ, power rating ≥ 0.125 W, tolerance ±1%.
    • Substitution latitude: Standard 0805 resistor.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CRCW0805200KFKEA

Passives: Capacitors

  • Ceramic Capacitors, 22 pF, 0805

    • Identity: Generic C0G / NP0 ceramic capacitors (SparkFun PROD_ID: CAP-11625 for C29, C33).
    • Quantity: 4 (C1, C2, C29, C33). C1 and C2 serve as crystal load caps for Q1.
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Capacitance 22 pF, voltage rating ≥ 25 V (50 V typical), dielectric C0G/NP0, tolerance ±5%.
    • Substitution latitude: Standard 0805 C0G ceramic capacitors.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CL21C220JBANNNC

  • Ceramic Bypass Capacitors, 0.1 µF (100 nF), 0805

    • Identity: Generic X7R / X5R ceramic bypass capacitors.
    • Quantity: 15 (C3, C4, C7, C9, C10, C11, C12, C15, C16, C19, C21, C23, C26, C27, and C32; C32 is labeled 100nf / CAP-11625).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Capacitance 0.1 µF (100 nF), voltage rating ≥ 25 V, dielectric X7R.
    • Substitution latitude: Standard 0805 bypass capacitors.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): C0805C104K5RACTU

  • Ceramic Capacitors, 1 µF, 0805

    • Identity: Generic X7R / X5R ceramic capacitors.
    • Quantity: 3 (C8, C18, C20).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Capacitance 1 µF, voltage rating ≥ 25 V, dielectric X7R/X5R.
    • Substitution latitude: Standard 0805 ceramic capacitors.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): C0805C105K3RACTU

  • Ceramic Capacitors, 10 µF, 0805

    • Identity: Generic X5R / X7R ceramic capacitors (SparkFun PROD_ID: CAP-11625 for C28).
    • Quantity: 4 (C5, C6, C13, C28).
    • Footprint / Package: 0805 (2012 metric).
    • Electrical constraints: Capacitance 10 µF, voltage rating ≥ 25 V (used on +12 V and +5 V power rails and AP63203 buck regulator).
    • Substitution latitude: Standard 0805 10 µF ceramic capacitors rated for ≥ 25 V.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): CL21A106KOQNNNE

  • Polarized Capacitors, 10 µF, EIA3216 (1206 Polarized)

    • Identity: Tantalum or solid electrolytic polarized capacitors.
    • Quantity: 2 (C14, C22).
    • Footprint / Package: EIA 3216-18 (Case A, 1206 footprint, polarized).
    • Electrical constraints: Capacitance 10 µF, voltage rating ≥ 16 V (20 V or 25 V recommended for 12 V rails), ESR ≤ 2 Ω.
    • Substitution latitude: Any EIA 3216 / 1206-A polarized tantalum or polymer aluminum capacitor rated ≥ 16 V.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): T491A106K016AT

  • Tantalum Capacitor, 10 µF, 0603-POLAR

    • Identity: AVX / KEMET small-footprint polarized tantalum capacitor (SparkFun PROD_ID: CAP-13210).
    • Quantity: 1 (C17).
    • Footprint / Package: 0603-POLAR (EIA 1608 metric).
    • Electrical constraints: Capacitance 10 µF, voltage rating ≥ 6.3 V, tolerance ±20%. Sits on the regulated 5 V or analog reference rail.
    • Substitution latitude: 0603 EIA 1608 polarized tantalum or high-capacitance ceramic capacitor rated ≥ 6.3 V.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): TLNK106M006R1500

Inductors, Resonator, and Protection

  • Power Inductor, 3.3 µH, NR5040 (5 mm × 5 mm)

    • Identity: Taiyo Yuden / Bourns NR5040 series (e.g. NR5040T3R3N) or equivalent shielded power inductor.
    • Quantity: 1 (L2).
    • Footprint / Package: NR5040 SMD (4.9 mm × 4.9 mm × 4.0 mm).
    • Electrical constraints: Inductance 3.3 µH ±20%, saturation current ISAT ≥ 2.5 A, DC resistance DCR ≤ 40 mΩ. Serves as output filter inductor for the AP63203 buck converter.
    • Substitution latitude: Any shielded surface-mount power inductor with 5 mm × 5 mm footprint rated for ≥ 2 A continuous saturation current.
    • Operated control: No.
    • Sourcing plan: distributor lookup: NR5040T3R3N

  • Ferrite Bead, 330 Ω @ 100 MHz, 0805

    • Identity: Murata BLM21PG331SN1D.
    • Quantity: 1 (L3).
    • Footprint / Package: 0805 (2012 metric, INDC2012X87).
    • Electrical constraints: Impedance 330 Ω ±25% at 100 MHz, DC current rating 1.5 A, DC resistance DCR ≤ 70 mΩ.
    • Substitution latitude: Any 0805 ferrite bead with impedance 300–400 Ω at 100 MHz and current capacity ≥ 1.5 A.
    • Operated control: No.
    • Sourcing plan: distributor lookup: BLM21PG331SN1D

  • Crystal Resonator, 16.000 MHz, NX3225

    • Identity: NDK NX3225SA-16.000M / Abracon ABM8G-16.000MHZ (schematic/board package NX3225, value 16.000 MHz).
    • Quantity: 1 (Q1).
    • Footprint / Package: 3.2 mm × 2.5 mm 4-pad surface mount (SMD-4 / NX3225).
    • Electrical constraints: Fundamental frequency 16.000 MHz, load capacitance 18–20 pF (matches C1/C2 load network), frequency tolerance ±20 ppm.
    • Substitution latitude: Any 16.000 MHz crystal in standard 3225 4-pad package with matched load capacitance.
    • Operated control: No.
    • Sourcing plan: distributor lookup: NX3225SA-16.000M-STD-CRS-2

  • AC Mains Input Fuse, 1.6 A

    • Identity: Bel Fuse 1.6 A surface mount / micro fuse (footprint BELFUSE1A, value BEL1.6AFUSE).
    • Quantity: 1 (F1).
    • Footprint / Package: Bel Fuse through-hole/surface footprint BELFUSE1A (2-pin, 5.08 mm pad span).
    • Electrical constraints: Current rating 1.6 A, voltage rating ≥ 277 VAC / 300 VAC, slow-blow / time-lag characteristic to tolerate inrush currents from the Mean Well power module.
    • Substitution latitude: Bel Fuse 0679H / 0679L series or equivalent 1.6 A / 250–300 VAC rated fuse matching footprint BELFUSE1A.
    • Operated control: No.
    • Sourcing plan: distributor lookup: 0679L1600-01

  • Onboard AC/DC Power Supply Module, 10 W, 12 VDC

    • Identity: Mean Well IRM-10-12 (note discrepancy: library device name is IRM-10-5, but value on schematic and silkscreen/photo in Rev 1 drawing is IRM-10-12).
    • Quantity: 1 (PS1).
    • Footprint / Package: Mean Well 4-pin through-hole encapsulated module (45.7 mm × 25.4 mm × 21.5 mm).
    • Electrical constraints: Universal AC input 85–305 VAC (supports 100–277 VAC nominal), 47–63 Hz; output 12 VDC at 0.85 A (10.2 W max); operating temperature up to 85 °C. An IRM-10-5 (5 V output) must NOT be substituted because the circuit requires +12 V to drive the relay coil, the TC1044S -12V inverter, and the AP63203 step-down regulator.
    • Substitution latitude: Must be Mean Well IRM-10-12 or pin-compatible encapsulated 12 VDC 10 W power module matching the IRM-10 series mechanical pin pitch.
    • Operated control: No.
    • Sourcing plan: distributor lookup: IRM-10-12

Connectors, Headers, and Test Points

  • AC Input and Relay Terminal Header, JST VH 6-pin

    • Identity: JST (Japan Solderless Terminal) B6P-VH (header footprint JST-VH-6).
    • Quantity: 1 (AC).
    • Footprint / Package: JST VH 3.96 mm pitch, 6-pin single row through-hole shrouded header.
    • Electrical constraints: Rated voltage 250 VAC, rated current 10 A. Pinout: AC_LINE_IN, AC_NEUTRAL_IN, AC_NEUTRAL_IN, AC_RELAY, AC_TEST_2, AC_TEST_1.
    • Substitution latitude: Must mate with JST VHR-6N housing. Pin-compatible 3.96 mm friction-lock headers (e.g. Molex Spox 5195/5277) may be used if mating housing is matched.
    • Operated control: No.
    • Sourcing plan: distributor lookup: B6P-VH

  • Current Measurement CT Header, 2-pin

    • Identity: Molex KK 254 / Friction Lock 2-pin header (package MOLEX_2, 2.54 mm pitch).
    • Quantity: 1 (AMP_CT).
    • Footprint / Package: 2-pin 2.54 mm (0.1") through-hole header.
    • Electrical constraints: Connects to external Current Transformer (CR8450-1K-T7QC).
    • Substitution latitude: Any standard 2-pin 0.1" (2.54 mm) friction-lock or breakaway header.
    • Operated control: No.
    • Sourcing plan: distributor lookup: 0022232021

  • GFCI CT Header, 4-pin

    • Identity: Molex KK 254 / 4-pin header (package GFCI_4, 2.54 mm pitch).
    • Quantity: 1 (GFCI_CT).
    • Footprint / Package: 4-pin 2.54 mm (0.1") through-hole header.
    • Electrical constraints: Pin 1: Self Test 1, Pin 2: Self Test 2, Pin 3: GFCI CT 1, Pin 4: GFCI CT 2. Connects to the differential ground-fault sense coil (CR8420-1K-GT7QC).
    • Substitution latitude: Standard 4-pin 0.1" (2.54 mm) friction lock header.
    • Operated control: No.
    • Sourcing plan: distributor lookup: 0022232041

  • DC Relay Driver Output Header, 3-pin

    • Identity: Molex KK 254 / 3-pin header (package MOLEX_3, 2.54 mm pitch).
    • Quantity: 1 (DC_RELAY).
    • Footprint / Package: 3-pin 2.54 mm (0.1") through-hole header.
    • Electrical constraints: Pin 1: DC Relay 2 GND, Pin 2: DC Relay C +12V, Pin 3: DC Relay 1 GND. Sinks current from external 12 VDC contactor coils.
    • Substitution latitude: Standard 3-pin 0.1" (2.54 mm) header.
    • Operated control: No.
    • Sourcing plan: distributor lookup: 0022232031

  • Serial / FTDI / WiFi Gateway Header, JST PH 6-pin

    • Identity: JST B6B-PH-K-S (package JST6, 2.00 mm pitch).
    • Quantity: 1 (FTDI).
    • Footprint / Package: 6-pin JST PH 2.0 mm pitch through-hole vertical shrouded header.
    • Electrical constraints: 5.0 V logic UART interface (GND, N/C, +5V, RX, TX, N/C). Connects to external ESP32 gateway module.
    • Substitution latitude: Any JST PH 6-pin 2.0 mm vertical shrouded header.
    • Operated control: No.
    • Sourcing plan: distributor lookup: B6B-PH-K-S(LF)(SN)

  • I2C Display Header, JST PH 4-pin

    • Identity: JST B4B-PH-K-S (SparkFun package JST-4-PTH-VERT, 2.00 mm pitch).
    • Quantity: 1 (I2C).
    • Footprint / Package: 4-pin JST PH 2.0 mm pitch through-hole vertical shrouded header.
    • Electrical constraints: 5 V logic I2C bus (GND, +5V, SCL, SDA). Connects to external I2C character or graphical LCD.
    • Substitution latitude: Any JST PH 4-pin 2.0 mm vertical shrouded header.
    • Operated control: No.
    • Sourcing plan: distributor lookup: B4B-PH-K-S(LF)(SN)

  • J1772 Control Signal Header, 6-pin Locking

    • Identity: Molex 22-23-2061 or equivalent locking header (package MOLEX-1X6_LOCK, 2.54 mm pitch).
    • Quantity: 1 (JP2).
    • Footprint / Package: 6-pin 2.54 mm (0.1") through-hole friction-lock header.
    • Electrical constraints: Pinout: CP Control Pilot, GND, PP Proximity Pilot IEC, GND, PP 2, +5V DC.
    • Substitution latitude: Standard 6-pin 0.1" friction-lock or standard pin header.
    • Operated control: No.
    • Sourcing plan: distributor lookup: 0022232061

  • Pilot / Proximity Screw Terminal Block, 2-position, 5 mm pitch

    • Identity: SparkFun PRT-08432 / Phoenix Contact 1985195 (package SCREWTERMINAL-5MM-2).
    • Quantity: 1 (PILOT).
    • Footprint / Package: 2-position 5.0 mm pitch through-hole screw terminal block.
    • Electrical constraints: Used for chassis connection of Control Pilot (CP) and Proximity Pilot (PP). Voltage rating ≥ 250 V, current rating ≥ 10 A.
    • Substitution latitude: Any standard 2-position 5.0 mm pitch through-hole terminal block.
    • Operated control: Screwdriver wire clamp for field wiring.
    • Sourcing plan: distributor lookup: 1985195

  • AVR In-System Programming (ISP) Header, 2×3 (6-pin)

    • Identity: Adafruit AVRISP / standard 2x3 dual-row male header, 2.54 mm pitch.
    • Quantity: 1 (ISP1).
    • Footprint / Package: 6-pin (2×3) through-hole header, 0.1" (2.54 mm) pitch.
    • Electrical constraints: Standard Atmel AVR ISP pinout (MISO, SCK, RESET, VCC, MOSI, GND).
    • Substitution latitude: Standard dual-row 2×3 0.1" male header.
    • Operated control: No.
    • Sourcing plan: distributor lookup: 67996-206HLF

  • Earth Ground Test / Solder Pads

    • Identity: SparkFun 1X01 PTH solder pad (drill diameter 1.31 mm, annular ring 2.6 mm).
    • Quantity: 2 (G1, G2).
    • Footprint / Package: Single-pad through-hole (1X01).
    • Electrical constraints: Chassis Earth Ground reference points for continuous ground monitoring circuit.
    • Substitution latitude: PCB pad; no physical part required, or soldered wire test point loop (e.g. Keystone 5001).
    • Operated control: No.
    • Sourcing plan: distributor lookup: 5001

PCB Mechanical and Trace Jumpers

  • Solder Jumpers / Zero-Ohm Trace Bridges

    • Identity: SHORT-HT5 / SHORT_TOP-50 (trace shorting bridge).
    • Quantity: 2 (SH1, SH2).
    • Footprint / Package: Surface mount copper jumper bridge (BOM: no).
    • Electrical constraints: Configures default copper connections; can be cut or bridged by solder.
    • Substitution latitude: Copper feature on PCB.
    • Operated control: No.
    • Sourcing plan: general web research: PCB copper trace feature

  • Optical Fiducials

    • Identity: SparkFun FIDUCIAL-1X2.5 (copper target with solder mask opening).
    • Quantity: 4 (FID1, FID2, FID3, FID4).
    • Footprint / Package: Fiducial circular copper target.
    • Electrical constraints: Mechanical optical alignment mark for pick-and-place machines.
    • Substitution latitude: Fabricated on PCB.
    • Operated control: No.
    • Sourcing plan: general web research: PCB copper feature

  • Mechanical PCB Mounting Holes

    • Identity: OpenEVSE HOLE (3.2 mm unplated/plated hole for M3 mounting screws).
    • Quantity: 2 (U$3, U$9).
    • Footprint / Package: 3.2 mm drill hole.
    • Electrical constraints: Non-conductive / ground chassis mounting.
    • Substitution latitude: Fabricated on PCB.
    • Operated control: No.
    • Sourcing plan: general web research: PCB drilled hole feature

External Parts Specified in Documents and Schematics

  • Ground Fault Current Transformer (GFCI CT Coil)

    • Identity: CR Magnetics CR8420-1K-GT7QC.
    • Quantity: 1.
    • Footprint / Package: Toroidal current transformer with integrated self-test primary winding and 0.187" quick-connect / wire leads.
    • Electrical constraints: Turns ratio 1000:1 with internal test loop; designed for low-level differential residual current sensing (detection of 5 mA – 20 mA AC leakage to ground).
    • Substitution latitude: Critical safety component. Must be exactly CR8420-1K-GT7QC or an OpenEVSE certified GFCI coil; changing coil inductance or turns ratio will decalibrate the hardware trip threshold.
    • Operated control: No.
    • Sourcing plan: distributor lookup: CR8420-1K-GT7QC

  • Current Measurement Current Transformer (Current CT Coil)

    • Identity: CR Magnetics CR8450-1K-T7QC.
    • Quantity: 1.
    • Footprint / Package: Toroidal current transformer with wire leads / quick-connect terminals.
    • Electrical constraints: Current rating up to 50 A AC (or 80 A max), 1000:1 turns ratio. Secondary connects across burden resistor R27 (2.0 Ω) to provide voltage proportional to charging current.
    • Substitution latitude: Must match the 1000:1 turns ratio and burden calibration of the OpenEVSE firmware.
    • Operated control: No.
    • Sourcing plan: distributor lookup: CR8450-1K-T7QC

  • AC Input Wiring Harness Connector Housing (JST VH)

    • Identity: JST VHR-6N.
    • Quantity: 1.
    • Footprint / Package: 6-position 3.96 mm pitch female connector housing.
    • Electrical constraints: Rated for 250 VAC, 10 A.
    • Substitution latitude: Generic JST VH 6-pin housing.
    • Operated control: No.
    • Sourcing plan: distributor lookup: VHR-6N

  • AC Input Wiring Harness Crimp Contacts (JST VH)

    • Identity: JST SVH-21T-P1.1.
    • Quantity: 6.
    • Footprint / Package: Crimp pin for 20–16 AWG wire.
    • Electrical constraints: Rated for 10 A continuous.
    • Substitution latitude: JST SVH-21T-P1.1 or SVH-41T-P1.1 (for 16–14 AWG wire).
    • Operated control: No.
    • Sourcing plan: distributor lookup: SVH-21T-P1.1

  • JST PH 4-Pin and 6-Pin Wiring Assemblies

    • Identity: JST PH series 2.0 mm pitch crimp housings (PHR-4, PHR-6) and pre-crimped wire leads (SPH-002T-P0.5S).
    • Quantity: 1 each (for FTDI/Serial and I2C connections).
    • Footprint / Package: 2.0 mm female housing with flying leads.
    • Electrical constraints: Low-voltage 5 VDC logic signal interconnects.
    • Substitution latitude: Standard commercial 2.0 mm JST PH 4-pin and 6-pin cable assemblies.
    • Operated control: No.
    • Sourcing plan: retail shopping search: JST PH 4 pin 6 pin pre-crimped wire harness

  • External AC Contactor / Relay

    • Identity: Double-pole single-throw (DPST-NO) AC power contactor, 40 A to 50 A continuous rating, 12 VDC or 120/240 VAC coil.
    • Quantity: 1.
    • Footprint / Package: Chassis / DIN-rail mount power contactor.
    • Electrical constraints: Contacts rated for 240/277 VAC, 40 A–50 A inductive/resistive EV charging load. Coil voltage matches the configured driver: 120/240 VAC coil (driven by onboard AQH2223 triac SSR via AC connector) or 12 VDC coil (driven by Q3 via DC_RELAY connector).
    • Substitution latitude: Any UL-recognized definite purpose contactor rated ≥ 40 A with matching coil voltage.
    • Operated control: No.
    • Sourcing plan: distributor lookup (representative example — sources give spec only): 899-1CH-F-C-12VDC

Software and network dependencies

  • Safety Controller Firmware (open_evse)

    • Identity: OpenEVSE AVR controller firmware for ATmega328P.
    • Repository: https://github.com/OpenEVSE/open_evse
    • Version: Recommended 9.0.0, minimum 7.1.3 (stated in documentation esp32_wifi_README.md and OpenEVSE_PLUS_README.md).
    • Where the version came from: stated in documentation.
    • Version pinning: Concrete version recommended in documentation (9.0.0).
    • Network exposure: None on the ATmega328P directly. MCU communicates strictly over local asynchronous serial UART (RAPI protocol, 115200 baud, 8-N-1) with the ESP32 gateway.
    • Check plan: not checkable: vendor firmware repository with no public CVE advisory database

  • ESP32 WiFi Gateway Firmware (openevse_esp32_firmware / ESP32_WiFi_V4.x)

    • Identity: OpenEVSE WiFi 3.x / 4.x gateway firmware for ESP32.
    • Repository: https://github.com/OpenEVSE/ESP32_WiFi_V4.x (or ESP32_WiFi_V3.x).
    • Version: not stated in the sources (lab documentation does not quote its own release version; recommends OpenEVSE controller FW 9.0.0).
    • Where the version came from: not stated.
    • Build system / Manifest: PlatformIO Core (esp32_wifi_platformio.ini).
    • Base Platform Toolchains:
      • espressif32@7.1.0 (Core 2.x default for 4MB boards): pinned in esp32_wifi_platformio.ini. Check plan: support-status lookup: espressif32 7.1.0
      • platform-espressif32@55.03.311 (Core 3.x / ESP-IDF 5.5.4 for 16MB+ boards via pioarduino): pinned in esp32_wifi_platformio.ini. Check plan: support-status lookup: platform-espressif32 55.03.311
    • Pinned Library Dependencies in esp32_wifi_platformio.ini:
      • bblanchon/ArduinoJson version 6.20.1: pinned in esp32_wifi_platformio.ini. Check plan: vulnerability lookup: ArduinoJson / PlatformIO / 6.20.1
      • jeremypoulter/ArduinoMongoose: pinned to git commit ca0a817de014cf4ab1833b32383532366fca10d7 in esp32_wifi_platformio.ini. Check plan: not checkable: git commit reference
      • jeremypoulter/Micro Debug version 0.0.5: pinned in esp32_wifi_platformio.ini. Check plan: not checkable: no package advisory database for author library
      • jeremypoulter/ConfigJson version 0.0.6: pinned in esp32_wifi_platformio.ini. Check plan: not checkable: no package advisory database for author library
      • OpenEVSE/OpenEVSE_Lib: pinned to git tag v0.0.20 in esp32_wifi_platformio.ini. Check plan: not checkable: git tag reference
      • jeremypoulter/ESPAL version 0.0.7: pinned in esp32_wifi_platformio.ini. Check plan: not checkable: no package advisory database for author library
      • jeremypoulter/StreamSpy version 0.0.2: pinned in esp32_wifi_platformio.ini. Check plan: not checkable: no package advisory database for author library
      • jeremypoulter/MicroTasks version 0.0.4: pinned in esp32_wifi_platformio.ini. Check plan: not checkable: no package advisory database for author library
      • matth-x/MicroOcpp version 1.2.0: pinned in esp32_wifi_platformio.ini. Check plan: vulnerability lookup: MicroOcpp / PlatformIO / 1.2.0
      • matth-x/MicroOcppMongoose version 1.2.0: pinned in esp32_wifi_platformio.ini. Check plan: vulnerability lookup: MicroOcppMongoose / PlatformIO / 1.2.0
      • adafruit/Adafruit MCP9808 Library version 2.0.2: pinned in esp32_wifi_platformio.ini. Check plan: vulnerability lookup: Adafruit MCP9808 Library / PlatformIO / 2.0.2
      • adafruit/Adafruit NeoPixel version 1.15.5: pinned in esp32_wifi_platformio.ini. Check plan: vulnerability lookup: Adafruit NeoPixel / PlatformIO / 1.15.5
      • kitesurfer1404/WS2812FX version 1.4.7: pinned in esp32_wifi_platformio.ini. Check plan: vulnerability lookup: WS2812FX / PlatformIO / 1.4.7
      • rar/esp_tsdb version 2.4.3: pinned in esp32_wifi_platformio.ini. Check plan: vulnerability lookup: esp_tsdb / PlatformIO / 2.4.3
    • Unpinned / Range Library Dependencies in esp32_wifi_platformio.ini:
      • bodmer/TFT_eSPI@^2.5.43 (unpinned caret range)
      • bitbank2/PNGdec@^1.1.5 (unpinned caret range)
      • lvgl/lvgl@^8.3.9 (unpinned caret range)
      • Check plans: not checkable: unpinned caret version range in esp32_wifi_platformio.ini
    • Network Exposure:
      • Interfaces: Wi-Fi (802.11 b/g/n station mode and fallback AP access point mode) and optional wired 10/100 Ethernet (LAN8720 PHY on Olimex / WT32-ETH01 hardware).
      • Services & Ports:
        • HTTP Server listening on port 80 (and port 8000 in native builds).
        • HTTPS Server listening on port 443 (and port 8443 in native builds) when TLS certificates are configured.
        • WebSocket live stream for telemetry and RAPI passthrough on port 80/443.
        • Multicast DNS (mDNS) advertising hostname openevse.local.
        • SNTP client (port 123 outbound) for time synchronization.
        • MQTT / MQTTS client (port 1883/8883 outbound) for status reporting and Home Assistant integration.
        • OCPP 1.6-J client over outbound WebSocket (port 80/443).
        • OTA firmware upload endpoint via HTTP POST to /update.
      • Default credentials: Not stated in the sources (device launches a first-run setup wizard for Wi-Fi credentials and HTTP admin authentication).

External Downloads and Resources

Fabrication Specifications

  • PCB Dimensions: 91.14 mm × 51.27 mm (3.588 in × 2.019 in).
  • Layer Count: 2 copper layers (Top: Layer 1, Bottom: Layer 16).
  • Solder Mask: Top and bottom layers.
  • Silkscreen: Top and bottom component legends and warning notices.
  • Minimum Finished Drill: 0.9 mm (for 2.54 mm pin headers), 1.0 mm (for F1 fuse pads), 1.31 mm (for Earth Ground pads G1/G2), 3.2 mm (for mechanical mounting holes U$3 and U$9).
  • High-Voltage Creepage / Clearance: Milling isolation slot and silkscreen division between high-voltage AC mains section (Mean Well PS1, AC connector, MOVs, 180 kΩ dropping resistors) and the low-voltage DC logic and communication circuitry. Clearance must satisfy UL/IEC standards for 277 VAC mains isolation (≥ 3.2 mm clearance, ≥ 6.4 mm creepage).