2 layers100 × 80 mm Meganecan gw, the printed circuit board in 3D

Meganecan gw

ESP32-based CAN-bus companion for Renault Megane 2 infotainment displays.

Size: 100 × 80 mm
Copper layers: 2
Thickness: 1.6 mm
Parts: 68
Nets: 76
Pads: 236
Tracks, vias: 573, 379
Pours: 2
Routed: Yes
KiCad: KiCad 10.0 (file 20260206)
Created: 2 Apr 2025
Updated: 1 Oct 2026

Overview

Meganecan gw is an open-source printed circuit board by Barbedx, from the Barbedx/MeganeCAN repository on GitHub. It is a 2-layer board of 100 × 80 mm with 68 parts on 76 nets, routed with 573 tracks and 379 vias.

It is built around the SN65HVD230D, LM2596S-3.3 and ESP32-WROVER-IB, with the NUP2105L, 1812L110/16V and SMBJ24A among its other parts. Its parts include 18 capacitors, 16 resistors, 8 diodes, 7 connectors and 5 ICs. It belongs with the ESP32 and RISC-V boards of this library.

Main components

README

README.md

MeganeCAN

ESP32-based CAN-bus companion for Renault Megane 2 infotainment displays.

Connects an ESP32 to the car CAN bus and acts as a smart sidecar: renders custom menus and text on the OEM display, bridges phone media controls via Bluetooth (Apple Media Service or BLE Keyboard), exposes a web UI for live configuration, and supports OTA firmware updates. Optional ELM327/OBD diagnostics via WiFi.

🇺🇦 When you use this project, you automatically support Ukraine.

⚠️ Safety: hobby project for off-road / testing use. Do not interact with menus while driving.

Features

Category	Details
CAN bus	500 Kbps, GPIO 3 (RX) / GPIO 4 (TX). Listens to OEM frames and replies to sync/ack.
Display	Emulates the head-unit radio over ISO-TP-style CAN to drive the OEM display. Two radio protocols: Carminat (large monochrome display only) and UpdateList (both the monochrome `updatelist_menu` and the 8-segment `updatelist`).
Bluetooth	AMS mode: advertises as a BLE peripheral — the iPhone pairs from Settings → Bluetooth, then the ESP reads now-playing (AMS), notifications (ANCS) and clock (CTS) as a GATT client over that link. Keyboard mode: BLE HID peripheral.
Web UI	PsychicHttp async server on port 80. Configure display type, BT mode, text, time.
OTA	ElegantOTA at `/update`.
Diagnostics	ELM327 over WiFi STA (V-LINK adapter). Queries ECUs and exposes JSON at `/api/live`.

Hardware

Minimum:

ESP32-C3 (or ESP32) development board
CAN transceiver — SN65HVD230 / TJA1050 / MCP2551
Wiring to CAN-H, CAN-L, GND, and a fused 5 V supply

Do not add a second 120 Ω terminator if the bus is already terminated.

Pinout (ESP32-C3):

Signal	GPIO
CAN RX	3
CAN TX	4

Architecture

Class diagram

text

IDisplay  (pure virtual interface)
│  tick(), recv(), processEvents()
│  setText(), setState(), setTime()
│  showMenu(), ProcessKey(), onKeyPressed()
│
└── AffaDisplayBase  (abstract — ISO-TP CAN send engine)
      │  affa3_send() / affa3_do_send()
      │  funcs[] array  (registered CAN function IDs + ack state)
      │  _sync_status   (FAILED | PEER_ALIVE | START | FUNCSREG)
      │  setMediaInfo()  — virtual no-op, overridden by subclasses
      │  tickMedia()     — virtual no-op, overridden by subclasses
      │  setKeyHandler() — installs the key callback
      │
      ├── Affa2Base  (Affa2 CAN protocol — basic text, fallback default)
      │     funcs: { 0x121 SETTEXT, 0x1B1 DISPLAY_CTRL }
      │     sync ping: 0x3DF   filler: 0x81
      │     │
      │     ├── Affa2Display      (8-segment — adds media title scroll)
      │     │     + setMediaInfo()  builds "Artist - Title" string
      │     │     + tickMedia()     scrolls 8-char window every 400 ms
      │     │
      │     └── Affa2MenuDisplay  (full-LED — stub, same CAN protocol)
      │
      └── Affa3NavDisplay  (Affa3Nav "Carminat" — full nav display)

Main loop data flow

text

 ┌──────────┐   CAN frame   ┌──────────────────┐
 │ CAN bus  │ ────────────► │ gotFrame()        │
 └──────────┘               │ → display->recv() │
                            └──────────────────┘

 ┌───────────────┐  MediaInformation  ┌─────────────────────────┐
 │ BLE / AMS     │ ─────────────────► │ onDataUpdateCallback()  │
 │ (iPhone)      │                    │ → display->setMediaInfo()│
 └───────────────┘                    └─────────────────────────┘

 loop()
   ├── serialCommands.ReadSerial()
   ├── ElegantOTA.loop()
   ├── Bluetooth::Service()          (AMS mode)
   ├── display->tickMedia()          (non-blocking scroll)
   ├── auto-time sync via CTS        (AMS mode, once per connection)
   ├── display->processEvents()
   └── elmManager->tick()            (OBD, when WiFi connected)

BT key mapping

Physical key	AMS action	BLE Keyboard HID
Pause	TogglePlayPause	KEY_MEDIA_PLAY_PAUSE
RollUp	NextTrack	KEY_MEDIA_NEXT_TRACK
RollDown	PreviousTrack	KEY_MEDIA_PREVIOUS_TRACK
VolumeUp (hold)	VolumeUp ×15	KEY_MEDIA_VOLUME_UP

CAN packet IDs

Affa2 protocol (Affa2Base / Affa2Display / Affa2MenuDisplay)

Constant	ID	Direction	Purpose
`PACKET_ID_SYNC`	`0x3DF`	ESP32 → display	Alive ping
`PACKET_ID_SYNC_REPLY`	`0x3CF`	display → ESP32	Sync ack
`PACKET_ID_SETTEXT`	`0x121`	ESP32 → display	Set text
`PACKET_ID_DISPLAY_CTRL`	`0x1B1`	ESP32 → display	Enable (0x02) / Disable (0x00)
`PACKET_ID_KEYPRESSED`	`0x0A9`	display → ESP32	Key press event
`PACKET_REPLY_FLAG`	`0x400`	—	OR-mask on ID for ack frames
`PACKET_FILLER`	`0x81`	—	Padding byte

Affa3Nav (Carminat)

Constant	ID	Direction	Purpose
`PACKET_ID_SYNC`	`0x3AF`	ESP32 → display	Alive ping
`PACKET_ID_SYNC_REPLY`	`0x3CF`	display → ESP32	Sync ack
`PACKET_ID_SETTEXT` / `DISPLAY_CTRL`	`0x151`	ESP32 → display	Text + enable/disable (same ID, different payload)
`PACKET_ID_NAV`	`0x1F1`	ESP32 → display	Menu / nav data
`PACKET_ID_KEYPRESSED`	`0x1C1`	display → ESP32	Key press event
`PACKET_FILLER`	`0x00`	—	Padding byte

Scroll lock indicator byte (Affa3Nav showMenu):

Value	Meaning
`0x00`	No scroll arrows
`0x07`	Scroll up arrow
`0x0B`	Scroll down arrow
`0x0C`	Both arrows

Display types

Selected via NVS key config/display_type. Takes effect after restart.

NVS value	Class	Notes
`carminat` (default)	`CarminatDisplay`	Carminat protocol → large monochrome display: full media screen + interactive menu + notification popups
`updatelist_menu`	`UpdateListMenuDisplay`	UpdateList protocol → monochrome LCD (menu); extends `UpdateListDisplay`
`updatelist`	`UpdateListDisplay`	UpdateList protocol → 8-segment display; scrolls "Artist - Title" (8-char window, 400 ms/step) via AMS
(other / unset)	`UpdateListBase`	UpdateList protocol base — fallback

Note: older docs/sections below may still use the pre-rename class names (Affa2*/Affa3Nav*) and values (affa2/affa3). The authoritative model is the matrix above and CLAUDE.md.

NVS configuration keys

Namespace	Key	Type	Default	Values
`config`	`display_type`	String	`affa3nav`	`affa2` / `affa2menu` / `affa3` / `affa3nav`
`config`	`bt_mode`	String	`ams`	`ams` / `keyboard`
`config`	`auto_time`	Bool	`true`	Sync display clock from phone via CTS
`display`	`autoRestore`	Bool	`false`	Restore last text on boot
`display`	`lastText`	String	—	Last text shown (restored on boot)
`display`	`welcomeText`	String	—	Scroll on boot (overrides default)

Build & flash

bash

# Build
pio run

# Flash over USB
pio run -t upload

# Serial monitor (115200 baud)
pio device monitor

# Build + flash in one step
pio run -t upload && pio device monitor

Target: esp32-c3-devkitm-1 (see platformio.ini).

WiFi / secrets

Edit src/secrets.h (not tracked by git):

cpp

#define Soft_AP_WIFI_SSID "MeganeCAN"
#define Soft_AP_WIFI_PASS "yourpassword"

The file is ignored via:

bash

git update-index --assume-unchanged src/secrets.h

Web UI (`http://<device-ip>/`)

Route	Method	Purpose
`/`	GET	Main configuration page
`/setDisplay`	POST	Set display type, restarts ESP32
`/setbtmode`	POST	Set BT mode + auto_time, restarts ESP32
`/config/restore`	GET	Read (`?enable` absent) or write (`?enable=1/0`) auto-restore flag
`/static`	GET	Show static text (`?text=`, `?save` to persist)
`/scroll`	GET	Scroll text (`?text=`, `?save` to save as welcome)
`/settime`	GET	Set display clock (`?time=HHMM`)
`/setVoltage`	GET	Debug voltage override
`/getdisplaytype`	GET	Returns current NVS display_type string
`/getbtmode`	GET	Returns current NVS bt_mode string
`/getautotime`	GET	Returns `1` or `0`
`/getlasttext`	GET	Returns last saved text
`/getwelcometext`	GET	Returns saved welcome text
`/api/live`	GET	ELM327 diagnostic snapshot JSON
`/affa3/setMenu`	GET	Send menu frame (`?caption=`, `?name1=`, `?name2=`, `?scrollLock=`)
`/affa3test`	GET	Affa3 display test page
`/emulate`	GET	Button emulation page
`/emulate/key`	POST	Inject a key press (`?key=`, `?hold=`)
`/update`	GET	ElegantOTA firmware upload

Serial commands (115200 baud)

Command	Example	Effect
`e`	`e`	Enable display
`d`	`d`	Disable display
`st <HHMM>`	`st 1430`	Set display clock
`msr <text> [delay_ms]`	`msr HELLO 300`	Scroll text right
`msl <text> [delay_ms]`	`msl MEGANE 250`	Scroll text left

ELM327 / OBD diagnostics

Note: ELM327 connection is currently disabled in firmware (connectToElm() is commented out). The infrastructure is complete but needs WiFi STA / BLE coexistence tuning before re-enabling.

WiFi STA connects to V-LINK (open network, TCP 192.168.0.10:35000). Cycles through PID plans querying:

CAN header	ECU
`7E0`	Engine
`743`	Gearbox / transmission
`744`	HVAC
`745`	Additional
`74D`	Gearbox / alternator

Results exposed at GET /api/live as JSON. To add a PID plan: create PidPlan_XXX.h and register it in buildCombinedPlan() inside MyELMManager.h.

Source layout

text

src/
├── main.cpp                    — setup(), loop(), HandleKey(), initDisplay()
├── apple_media_service.cpp/.h  — BLE AMS client (NimBLE)
├── bluetooth.cpp/.h            — BLE scan + connect + CTS
├── current_time_service.cpp/.h — BLE Current Time Service (clock sync)
├── secrets.h                   — WiFi credentials (not tracked)
│
├── display/
│   ├── IDisplay.h              — pure virtual display interface
│   ├── AffaDisplayBase.cpp/.h  — ISO-TP CAN engine, sync state machine
│   ├── AffaCommonConstants.h   — shared enums (AffaKey, AffaError, SyncStatus…)
│   │
│   ├── Affa2/
│   │   ├── Affa2Constants.h         — Affa2 CAN packet IDs + namespace
│   │   ├── Affa2Base.cpp/.h         — Affa2 protocol implementation (base class)
│   │   ├── Affa2Display.h/.cpp      — 8-segment variant, Spotify title scroll
│   │   └── Affa2MenuDisplay.h       — full-LED variant stub
│   │
│   └── Affa3Nav/
│       ├── Affa3NavConstants.h
│       ├── Affa3NavDisplay.cpp/.h   — full media screen + menu system
│       ├── AuxModeTracker.cpp/.h
│       └── Menu/
│           ├── Menu.cpp/.h          — hierarchical menu (Field, List, MultiField)

Category and platform

ESP32 RISC-V

Project files

Show this board on your page

https://pcbkit.io/boards/Barbedx/MeganeCAN

The board's own page, for a message or a post.

Source

Repository: Barbedx/MeganeCAN
Board file: hardware/meganecan-gw/meganecan-gw.kicad_pcb
Commit: db5c477
Licence: Not stated

Parts

Qty	Value	Footprint	References
9	100nF/50V X7R	Capacitor_SMD:C_0805_2012Metric_Pad1.18x1.45mm_HandSolder	C2, C5, C6, C8, C10, C12, C13, C15, C18
4	1k	Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder	R7, R13, R14, R15
4	60.4R	Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder	R9, R10, R11, R12
4	MountingHole_3.2mm_M3	MountingHole:MountingHole_3.2mm_M3	H1, H2, H3, H4
3	10k	Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder	R2, R3, R4
3	10uF/16V X5R	Capacitor_SMD:C_0805_2012Metric_Pad1.18x1.45mm_HandSolder	C4, C9, C11
2	0R	Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder	R5, R6
2	100uF/50V	Capacitor_THT:CP_Radial_D10.0mm_P5.00mm	C1, C16
2	NUP2105L	Package_TO_SOT_SMD:SOT-23	D7, D8
2	SN65HVD230	Package_SO:SOIC-8_3.9x4.9mm_P1.27mm	U3, U4
1	10uF/50V X7R 1210	Capacitor_SMD:C_1210_3225Metric_Pad1.33x2.70mm_HandSolder	C17
1	1812L110/16	Fuse:Fuse_1812_4532Metric_Pad1.30x3.40mm_HandSolder	F1
1	220R	Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder	R8
1	220uF/6.3V low-ESR	Capacitor_THT:CP_Radial_D6.3mm_P2.50mm	C3
1	22uF/10V X7R 1210	Capacitor_SMD:C_1210_3225Metric_Pad1.33x2.70mm_HandSolder	C7
1	33uH/3A	Inductor_SMD:L_12x12mm_H8mm	L1
1	470R	Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder	R16
1	47k	Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder	R1
1	47uF/10V	Capacitor_THT:CP_Radial_D5.0mm_P2.00mm	C14
1	BLU	LED_SMD:LED_0805_2012Metric_Pad1.15x1.40mm_HandSolder	D5
1	BOOT	Button_Switch_THT:SW_PUSH_6mm	SW2
1	BUCK-ALT	Connector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_Vertical	J7
1	ESP32-C3 SuperMini	MeganeCAN:MODULE_ESP32-C3-SUPERMINI	U2
1	ESP32-WROVER-IB	MeganeCAN:ESP32-WROVER-IB	U1
1	EXP	Connector_PinHeader_2.54mm:PinHeader_1x12_P2.54mm_Vertical	J6
1	GRN	LED_SMD:LED_0805_2012Metric_Pad1.15x1.40mm_HandSolder	D4
1	HU	Connector_JST:JST_XH_B3B-XH-A_1x03_P2.50mm_Vertical	J4
1	JIG	Connector_PinHeader_2.54mm:PinHeader_1x06_P2.54mm_Vertical	J5
1	LM2596S-3.3	Package_TO_SOT_SMD:TO-263-5_TabPin3	U5
1	MMCAN	TerminalBlock_Phoenix:TerminalBlock_Phoenix_MKDS-1,5-3-5.08_1x03_P5.08mm_Horizontal	J3
1	MMCAN-TERM-H	Jumper:SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm	JP3
1	MMCAN-TERM-L	Jumper:SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm	JP5
1	Mini-360 (MP2307)	MeganeCAN:MINI360_4pad_Socket	PS1
1	PWR	TerminalBlock_Phoenix:TerminalBlock_Phoenix_MKDS-1,5-3-5.08_1x03_P5.08mm_Horizontal	J1
1	RESET	Button_Switch_THT:SW_PUSH_6mm	SW1
1	SMBJ24A	Diode_SMD:D_SMB_Handsoldering	D2
1	SRC-SEL	Jumper:SolderJumper-3_P1.3mm_Bridged12_RoundedPad1.0x1.5mm	JP1
1	SS34	Diode_SMD:D_SMA-SMB_Universal_Handsoldering	D3
1	SS36	Diode_SMD:D_SMA-SMB_Universal_Handsoldering	D6
1	SS56	Diode_SMD:D_SMA-SMB_Universal_Handsoldering	D1
1	VCAN	TerminalBlock_Phoenix:TerminalBlock_Phoenix_MKDS-1,5-3-5.08_1x03_P5.08mm_Horizontal	J2
1	VCAN-TERM-H	Jumper:SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm	JP2
1	VCAN-TERM-L	Jumper:SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm	JP4

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Questions

How big is the Meganecan gw PCB?

It measures 100 × 80 mm and has 2 copper layers, 1.6 mm thick.

What parts does the Meganecan gw use?

68 parts, built around the SN65HVD230D, LM2596S-3.3, ESP32-WROVER-IB and NUP2105L. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.

Where can I download the Meganecan gw KiCad files?

From the Barbedx/MeganeCAN repository on GitHub, at the commit this page was made from: the board is hardware/meganecan-gw/meganecan-gw.kicad_pcb and its schematic hardware/meganecan-gw/meganecan-gw.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the Meganecan gw design in my own project?

Its repository states no licence, so its author keeps all rights: ask Barbedx before reusing the design.

Overview

Main components

SN65HVD230D

LM2596S-3.3

ESP32-WROVER-IB

NUP2105L

1812L110/16V

SMBJ24A

SS34

SS36

SS56

README

MeganeCAN

Features

Hardware

Architecture

Class diagram

Main loop data flow

BT key mapping

CAN packet IDs

Affa2 protocol (Affa2Base / Affa2Display / Affa2MenuDisplay)

Affa3Nav (Carminat)

Display types

NVS configuration keys

Build & flash

WiFi / secrets

Web UI (http://<device-ip>/)

Serial commands (115200 baud)

ELM327 / OBD diagnostics

Source layout

Parts

Similar boards

Questions

How big is the Meganecan gw PCB?

What parts does the Meganecan gw use?

Where can I download the Meganecan gw KiCad files?

Can I use the Meganecan gw design in my own project?

Web UI (`http://<device-ip>/`)