FISCuntrolCAN

FISCuntrolCAN turns the FIS — the driver-information display in the middle of a VW/Audi instrument cluster — into a live data screen for your engine and chassis. It reads the car's chassis CAN bus (speed, RPM, pedal, Haldex, EML/EPC) and can also talk KWP1281 over K-line for diagnostic measuring blocks and fault codes, then displays it all onto the cluster as scrollable "cards" you flick through with the wiper-stalk buttons. It additionally decodes a standalone Ignitron ECU broadcast, co-operates with an OpenHaldex controller, and is configured entirely from a phone over Wi-Fi — no laptop or serial cable needed in the car. OTA updates and live diagnostics.

It is based on an ESP32 DevKit V1 (WROOM-32) running the Arduino framework, and is built around the excellent TLBFISLib, KLineKWP1281Lib_ESP32 and TLBLib libraries by domnulvlad, which implement the proprietary 3-wire FIS protocol and the KWP1281 diagnostic protocols.

Features at a Glance

Feature	Detail
CAN input	500 kbit/s TWAI, accept-all filter — VAG MOTOR / Haldex / Ignitron decoders
K-line input	KWP1281 measuring blocks + fault-code read/clear (Engine, Gearbox, ABS, Airbag, Cluster)
FIS output	Live "cards" drawn over the proprietary 3-wire FIS bus via a level shifter
On-screen menu	Stalk-button driven SOURCE menu (K-Line / CAN / Ignitron / Haldex / Settings / Exit)
Ignitron view	Decodes the dashCAN "ICD01" sensor broadcast on `0x600–0x604` into paged cards
OpenHaldex	Broadcasts mode + pedal threshold + override so a Haldex controller can co-operate
Stalk control	Mimics / pulses the three stalk-button outputs to drive the cluster's own menus
Wi-Fi UI	Web app — config, diagnostics, OTA
OTA updates	Firmware and filesystem (web UI) flashed from the browser
Boot screens	Selectable splash bitmaps, or a personalised time-of-day greeting
Special dates	Up to 5 custom multi-line messages shown on matching calendar days (override the logo)
Device clock	Browser-synced time (no NTP needed in AP mode), optional DS1307 RTC, persisted to EEPROM
RPM shift light	Full-screen logo overlay above a configurable RPM threshold
Oil sensor	Optional single-wire Hella/VAG G266 oil level + temperature decoder WIP
Power management	Auto Wi-Fi-off + CPU scaling 1 min after the last client disconnects
Remembers settings	Nav state and configuration stored to ESP32 Preferences (NVS)

Compatibility

Designed for VW/Audi clusters that carry a FIS driven by the 3-wire (ENA / CLK / DATA) protocol — e.g. MK4 Golf / Bora, B5–B6 Passat, and contemporary Audi A3 / A4 / TT clusters. CAN decoding targets the classic VAG powertrain frame set (MOTOR1/2/5, HALDEX), and K-line targets KWP1281 control modules. The Ignitron view targets the dashCAN "ICD01" custom-CAN broadcast.

Frame IDs, decoders and calibration are car-specific. Treat the supplied decoders as a known-good MK4 baseline and adjust config.h to suit your vehicle.

Hardware Overview

External Interfaces

Function	Part / circuit
CAN transceiver	TJA1050 / MCP2551 / SN65HVD230 — 500 kbit/s
K-line transceiver	KWP1281-capable transceiver (e.g. L9637, MC33290)
FIS bus	5 V cluster lines through a CJ74LVC4T245 level shifter (bidirectional `ENA`, unidirectional `CLK` / `DATA`)
Stalk buttons	One isolated input + one isolated output per stalk button (UP / DOWN / RESET)
Ignition sense	Resistor divider into GPIO 35 (ADC, with hysteresis)
External output	GPIO for switching an aux load via a driver
Optional RTC	DS1307 on I²C (SDA GPIO 21 / SCL GPIO 22) — enable with "Use RTC" in the UI
Optional oil sensor	12 V → 3.3 V level-shifted PWM signal on GPIO 4 WIP

Pin Map

Defined in include/config.h:

Group	Signal	GPIO
FIS (SPI)	CLK	18
	DATA (MOSI)	23
	ENA (CS)	19
	ENADIR (level-shifter direction)	32
K-line	TX / RX	17 / 16
CAN / TWAI	RX / TX	13 / 14
Stalk in	UP / DOWN / RESET	34 / 39 / 36
Stalk out	UP / DOWN / RESET	27 / 26 / 25
Misc	Ignition (ADC)	35
	External output	12
	Oil sensor (optional)	4
	RTC I²C SDA / SCL (optional)	21 / 22

Input-only pins: GPIO 34 / 36 / 39 have no internal pull-ups. The PCB must supply the pull-ups for the stalk inputs and the ignition-sense divider.

Board

The reference hardware is the FISCuntrol V3 board (Forbes Automotive), built around an ESP32 DevKit V1 (WROOM-32) with an on-board switching regulator, CAN and K-line transceivers, the FIS level shifter, and a single 18-way MX23A18NF1 connector.

Harness Connector

All vehicle wiring lands on one 18-way MX23A18NF1 connector (two rows of 9). Pin 1 is top-right, pin 9 top-left; pin 10 is bottom-right, pin 18 bottom-left when looking into the mating face.

Pin	Silk name	Function	Internal net / GPIO
1	`EXT_OUT`	Switched external / aux output	GPIO 12
2	—	Not connected	—
3	—	Not connected	—
4	`IN_UP_CONN`	Stalk UP button input	GPIO 34
5	`IN_DOWN_CONN`	Stalk DOWN button input	GPIO 39
6	`IN_RESET_CONN`	Stalk RESET button input	GPIO 36
7	`OUT_UP_CONN`	Stalk UP output (drive to cluster)	GPIO 27
8	`OUT_DOWN_CONN`	Stalk DOWN output (drive to cluster)	GPIO 26
9	`OUT_RESET_CONN`	Stalk RESET output (drive to cluster)	GPIO 25
10	`CHASSIS_CANH`	Chassis CAN High	CAN transceiver (RX 13)
11	`CHASSIS_CANL`	Chassis CAN Low	CAN transceiver (TX 14)
12	`FIS_ENA_5V`	FIS ENA (5 V, bidirectional)	GPIO 19 via CJ74LVC4T245
13	`FIS_DATA_5V`	FIS DATA (5 V)	GPIO 23 via CJ74LVC4T245
14	`FIS_CLK_5V`	FIS CLK (5 V)	GPIO 18 via CJ74LVC4T245
15	`MC33290_K`	K-line (KWP1281) via MC33290 transceiver	GPIO 17 / 16 (TX / RX)
16	`GND`	Ground	GND
17	`12V_IGN`	Ignition-switched 12 V (ignition sense)	ADC GPIO 35 (divider)
18	`12V_PERM`	Permanent 12 V supply	Regulator input

Silkscreen close-ups

Pins 1–6 · 10–15	Pins 6–9 · 15–18

Status LEDs

The board carries seven indicator LEDs for at-a-glance stalk and ignition I/O.

LED	Group	Indicates
LED1–LED3	Up / Down / Reset OUT	Board is pulsing an output to the cluster
LED4–LED6	Up / Down / Reset IN	A stalk button input is active
LED7	Ignition	`12V_IGN` is live (ignition on)

CAN Termination & RTC

Feature	Detail
`TERM1` jumper	Fit to enable the 120 Ω CAN bus termination; leave open when the board is not at the end of the bus
`RTC1` connector	4-pin I²C header (`SCL` / `SDA` / `5V` / `GND`) for an optional DS1307 RTC module — enable with Use RTC in the UI (SDA GPIO 21 / SCL GPIO 22)
`BOOT` button	ESP32 boot / flash button

How the Display Works

Multiple data sources feed a single shared "card" that the render task paints onto the FIS. Only one source is shown at a time; the active source is chosen by the on-screen menu and the stalk buttons.

CAN bus (500k)            K-line (KWP1281)        Ignitron ICD01 (0x600–0x604)
      │                         │                            │
      ▼ canTask (core 0)        ▼ klineTask (core 0)         ▼ canTask
 decode MOTOR1/2/5,        measuring blocks             capture frames,
 OpenHaldex, Ignitron      + fault codes                decode 16-bit signals
      │                         │                            │
      └────────────────┬────────┴────────────────────────────┘
                       ▼  shared globals  +  card store (FIS-line mutex)
                       ▼  parseFIS()  →  fisLine[0..7]
                       ▼  fisRenderTask (core 1)
                       ▼  TLBFISLib  →  FIS cluster screen

Card Sources

Source	Shows
`CAN`	Decoded MOTOR cards — RPM & pedal, speed, EML/EPC, plus raw bytes
`IGNITRON`	Paged Ignitron ICD01 sensor values (6 signals per card)
`K-LINE`	KWP1281 measuring-block values for the selected module
`HALDEX`	OpenHaldex mode, lock target, engagement, speed, pedal

On-Screen Menu

Long-press RESET opens the SOURCE menu. Items appear only when their hardware is available:

K-LINE (→ module sub-menu) · CAN · IGNITRON · HALDEX · EXIT

Stalk Buttons

The three stalk buttons are read with OneButton (single / double / long-press) and their meaning depends on the active source:

Gesture	In a menu	CAN / Ignitron	Haldex	K-line
UP — single	Navigate up	Next card / page	Mode +	Block +1
DOWN — single	Navigate down	Previous card / page	Mode −	Block −1
UP — double	—	—	—	Block +10
DOWN — double	—	—	—	Block −10
UP — long	—	Toggle CAN ↔ OpenHaldex (returns to the last CAN view)
DOWN — long	—	—	—	Block → 1
RESET — single	Select item	Open menu	Open menu	Open menu
RESET — long	Close menu	Open menu / re-enable FIS (toggles FIS off if not booted)

Last-CAN-view memory: the long-press-UP toggle simply flips between OpenHaldex and the CAN view you last selected. If you were on CAN it toggles CAN ↔ OpenHaldex; if you were on IGNITRON it toggles Ignitron ↔ OpenHaldex. The choice persists across power cycles (EEP).

Data Sources

CAN Decoders

The TWAI controller runs at 500 kbit/s with an accept-all filter, so every frame on the bus reaches the firmware. Built-in VAG decoders:

Frame	ID	Decoded into
`MOTOR1`	`0x280`	`vehicleRPM`, `pedValue`
`MOTOR2`	`0x288`	`vehicleSpeed` (km/h, optional → mph)
`MOTOR5`	`0x480`	`vehicleEML`, `vehicleEPC`
`openHaldex`	`0x6B0`	Haldex state, engagement, mode, speed
Ignitron ICD01	`0x600`–`0x604`	See Ignitron View

K-line (KWP1281)

When the boot source is K-line, the firmware connects to a control module over the K-line and polls measuring blocks. The menu's K-LINE sub-menu selects the module; reconnects are handled live with ret/fallback.

Module	Address
Engine	`0x01`
Gearbox	`0x02`
ABS	`0x03`
Airbag	`0x22`
Cluster	`0x23`

Fault codes can be read and cleared from the web UI's K-Line tab.

Ignitron View

The Ignitron standalone ECU broadcasts the dashCAN "ICD01" custom message set on frames 0x600–0x604. Each frame packs four little-endian 16-bit signals; FISCuntrolCAN captures the frames, decodes the signals (reversing the dashCAN scale/offset) and shows them as paged cards — 6 signals per card, so the 20-signal map fills four pages (IGN 1/4 … IGN 4/4). Page with the UP/DOWN stalk buttons.

Decoded signals include RPM, coolant, MAP, IAT, EGT, oil pressure/temperature, fuel rail pressure, lambda, pedal, speed, throttle position, battery voltage, ignition advance, short/long fuel trims and ECU torque.

OpenHaldex

When Haldex hardware is present, a background task broadcasts a FISCuntrol frame (0x6A0) carrying the selected mode every 50 ms, and reads the OpenHaldex status frame (0x6B0). Modes: Stock, FWD, 50/50, 60/40, 75/25, Expert. Change mode with UP/DOWN while the Haldex card is shown.

Wi-Fi & Web Interface

Connect to the FISCuntrolCAN Wi-Fi access point and browse to http://192.168.1.1/. The interface is a web app served from the ESP32's LittleFS partition; settings auto-save to NVS.

Tab	Purpose
FIS	Live FIS card preview, software stalk-button simulator, ignition restart
K-Line	Fault-code viewer + clear, module selector
CAN	CAN data card carousel
Settings	Boot source (CAN / K-line), boot screen, welcome greeting + name, special dates, Use RTC, per-category logging toggles, RPM-logo threshold, pin assignments, K-line default module
Logos	Upload a 704-byte boot bitmap or RPM-overlay bitmap
Diagnostics	CAN / K-line health, ignition state, free heap, FIS boot readiness, raw button-pin states, external-output control, device clock (browser / device / RTC time + RTC status)
OTA	Flash new firmware or a new filesystem image from the browser

Boot Greeting, Special Dates & Clock

The boot screen can show a personalised greeting instead of a logo. With Welcome Greeting enabled in the Settings tab you enter a name only and the device uses the time of day — GOOD MORNING / AFTERNOON / EVENING <name>. The greeting and a boot logo are mutually exclusive (turning the greeting on clears the selected logo).

Special Dates let you define up to five calendar days, each with its own custom multi-line message. On a matching day the message is shown on boot and overrides the logo for that day — even if the Welcome Greeting is off. A date left at the 1970 is treated as unset.

Both features need the clock time. The browser POSTs its local date/time to /api/time on every page load, the ESP32 advances that time with its internal clock and persists it to EEP so a reboot still has an approximate time. Enable Use RTC to additionally read/write a DS1307 on SDA = GPIO 21 / SCL = GPIO 22; when present and running the RTC is preferred on boot and kept in sync whenever the browser sets the time.

The Diagnostics tab's Device Clock panel shows the live browser time, the device time, the RTC time, and the RTC status (Healthy / Not healthy / Not detected). All greeting, special-date, name and Use-RTC settings are stored in EEP.

Power Management

The firmware bundles the universal power_manager module (shared with SpeedPulser Pro / Can2Cluster) that 1 minute after the last Wi-Fi client disconnects will reduce CPU usage and turn off WiFi. This reduces power consumption / heat generated.

Action	Saving
Wi-Fi radio off	~80–120 mA average (single biggest)
CPU 240 MHz → 80 MHz	Moderate reduction in active current
Bluetooth controller released at boot	~60 KB RAM freed; small idle saving
Onboard LED off at boot	Tiny but persistent saving

A power-cycle (ignition off/on) brings Wi-Fi back.

Oil Sensor (Optional)

Work In Progress! Decodes a single-wire Hella / VAG combined oil-level + oil-temperature sensor (G266 family, OE PNs around 1J0907660* / 06A907660*). Disabled by default (hasOilSensor 0).

The sensor is treated as a continuous ~18–30 Hz PWM (not the BMW/Hella 3-pulse frame): each cycle's period is mapped to oil temperature via a two-point linear fit, then EMA-filtered.
The temperature fit is seeded from real MK4 G266 captures (~36.5 ms ≈ 20 °C, ~54 ms ≈ 100 °C). Re-check it against a dash / CAN oil-temperature reading.
Oil level is not calibrated yet (oilSensorLevelCalibrated 0, level returns NAN) — the captures were made in water with the level pad dry.

To calibrate:

In config.h set hasOilSensor 1 and oilSensorRawLog 1.
Wire the sensor's signal via a 12 V → 3.3 V level shifter to GPIO 4 (change oilSensorPin for a different GPIO).
Watch Serial — every cycle prints [OIL] period=… us (… Hz) high=… us low=… us duty=…% T=…C cyc=… err=….
Tune the oilSensor* defines (oilSensorTempPeriod0Us/…1Us for temperature; the …Period…/…Pulse…Min/Max sanity windows) until oilSensorFrameCount rises and the temperature looks sane. For level, run an oil-bath depth test, set oilSensorLevelCalibrated 1 and fill in oilSensorLevelPulse0Us/…1Us.

void  setupOilSensor();                 // call from setup()
void  serviceOilSensor();               // call from loop()
float oilSensor_getTemperatureC();      // NAN if stale
float oilSensor_getLevelMm();           // NAN if stale
float oilSensor_getLevelPercent();      // 0..100, NAN if stale
bool  oilSensor_isPresent();
bool  oilSensor_hasValidReading();

Configuration

Feature Toggles

Define	Default	Effect
`enableDebug`	1	Mirror `DEBUG(...)` output to Serial.
`serialBaud`	115200	UART speed for the debug console.
`ChassisCANDebug`	0	Print every incoming TWAI frame.
`checkLED`	0	Run a one-shot LED test at boot.
`detailedDebugWiFi`	0	Verbose Wi-Fi events.
`hasRTC`	0	Legacy compile flag; the DS1307 RTC is now toggled at runtime via Use RTC in the UI.
`isMPH`	1	Convert km/h → mph (`mphFactor` constant).
`hasOilSensor`	0	Compile in the oil-sensor decoder.
`oilSensorRawLog`	0	Print every decoded oil-sensor pulse to Serial.
`defaultBootScreen`	2	0=off, 1=text, 2=MK4Golf, 3=logo, 4=finger, 5=BMP.

Timing Knobs

fisWakeDelay, fisBootTimeoutMs, bootScreenDuration, logFrequency, canRefresh, connectionDelayDuration, fisStatusCardHoldMs — tune per car if the cluster behaves differently.

Software Architecture

The Arduino loop() runs on core 1; CAN reception and other long-lived jobs run as dedicated FreeRTOS tasks on core 0.

Modules

Module	Responsibility
`config.*`	All compile-time defines, pin map, CAN IDs, shared globals + `extern` decls
`main.cpp`	`setup()` / `loop()`, ignition status, button-output + oil-sensor monitoring
`onboot.cpp`	GPIO init, boot sequence, connection launch/shutdown
`tasks.cpp`	FreeRTOS task creation (CAN RX, FIS render, K-line poll, Haldex broadcast)
`can_bus.cpp`	TWAI driver + frame capture; MOTOR + Ignitron card decode/render
`kline.cpp`	KWP1281 measuring-block reads + fault-code clear via Serial2
`fis_display.cpp`	TLBFISLib wrapper + rendering
`fis_menu.cpp`	On-FIS SOURCE menu
`cards.cpp`	FIS "card" store with source switching (mutex-protected)
`buttons.cpp`	OneButton wrappers for the stalk inputs + stalk-output pulse generator
`bootLogos.cpp` / `bootmessage.cpp`	Boot splash bitmaps + user-configurable greeting / special-date messages
`timekeeper.cpp`	Device clock — browser time sync, optional DS1307 RTC, EEP
`web_server.cpp`	Wi-Fi AP + AsyncWebServer, JSON API, OTA, LittleFS-served UI
`oil_sensor.cpp`	Optional Hella oil-level + temperature decoder

FreeRTOS Tasks

Task	Core	Priority	Job
`CAN_RX`	0	2	Drain TWAI, update telemetry globals, feed Ignitron
`FIS_RENDER`	1	2	Render menu / card / RPM overlay / K-line / Haldex
`KLINE_POLL`	0	1	Poll KWP1281 measurements, handle module reconnect
`OH_BCAST`	0	1	Broadcast OpenHaldex frame (50 ms cadence)

`setup()` Order

Serial.begin() (if enableDebug / ChassisCANDebug)
setupWiFi() → setupWebServer() → timeInit()
powerInit() — start the background power-manager task
initCardMutex() — before any task that calls commitCard() / displayFIS()
setupPins() — GPIO directions, pull-ups, external output
setupButtons() — stalk OneButton handlers + ISRs
setupOilSensor() — attaches the edge ISR if hasOilSensor is on
startTasks() — launch the FreeRTOS tasks above

`loop()` Services

ADC ignition sampling with hysteresis (20 ms) · button-output pulse servicing · oil-sensor pulse decode · ignition rise/fall → boot/shutdown · FIS enable/disable toggle · 200 ms diagnostic Serial print.

Technical Reference

CAN / TWAI

Parameter	Value
Baud	500 kbit/s
Mode	Normal, accept-all filter
Driver	ESP-IDF `driver/twai.h` (native)

Key CAN IDs

ID	Use
`0x280` / `0x288` / `0x480`	VAG `MOTOR1` / `MOTOR2` / `MOTOR5`
`0x600`–`0x604`	Ignitron ICD01 sensor broadcast
`0x6A0`	FISCuntrol → OpenHaldex mode
`0x6B0`	OpenHaldex → FISCuntrol status

PlatformIO Dependencies

Library	Purpose
`me-no-dev/ESPAsyncWebServer` + `me-no-dev/AsyncTCP`	Async web server + TCP
`bblanchon/ArduinoJson`	JSON for the REST API
`mathertel/OneButton`	Stalk-button gesture decoding
`adafruit/RTClib`	Optional DS1307 RTC
`domnulvlad/TLBFISLib`	FIS rendering over the 3-wire bus
`domnulvlad/KLineKWP1281Lib_ESP32`	KWP1281 diagnostic stack
`domnulvlad/TLBLib`	Low-level FIS transport

Platform: pioarduino/platform-espressif32 54.03.20 (Arduino-ESP32 3.x / ESP-IDF 5.x).

Version History

Version	Highlights
Unreleased	Personalised boot Welcome Greeting (name only; device adds the time-of-day prefix) and 5 configurable special-date messages that override the boot logo. New timekeeper module: browser-synced device clock (`/api/time`), optional DS1307 RTC on SDA 21 / SCL 22, and NVS persistence of the epoch. Diagnostics gained a Device Clock panel showing browser / device / RTC time plus RTC health. All new settings persisted to NVS.
Logging & task refactor	Categorised serial/UI logging (SYS / CAN / K-LINE / IO / WIFI) with per-category toggles in the UI; `parseFIS()` moved into `fis_display`, CAN tasks consolidated into `can_bus`; dedicated FreeRTOS tasks for ignition fallback, button outputs and the (UI-disable-able) oil sensor.
Baseline	CAN + K-line + Ignitron + OpenHaldex unified card system, Wi-Fi single-page UI, OTA (firmware + filesystem), RPM shift-light overlay, optional oil-sensor decoder and the shared power-management module.

Disclaimer

FISCuntrolCAN displays vehicle data for information only and interfaces with a vehicle's diagnostic and CAN buses. Always assume readings are approximate. Use at your own risk — incorrect frame IDs, decoders or wiring can affect bus behaviour. Test on the bench before fitting to a car.

Name		Name	Last commit message	Last commit date
Code		Code
Enclosure		Enclosure
Images		Images
Installation Guide		Installation Guide
PCB		PCB
PlatformIO		PlatformIO
.gitattributes		.gitattributes
README.md		README.md

Latest commit

History

Folders and files

Repository files navigation