Renault Clio III CANBUS research/improvement

Mikescotland

picasso1850 if I only had all documentation.

picasso1850

Mikescotland I agree with you that detailed documentation is lacking.

But I disagree that technical support or OS upgrades or bug fixes is lacking, or that this isn't the best product on the market relative to the rest of the comparable units. And we can't compare features or functions of a kenwood or sony unit to this product. Its not apples to apples.

I think my posts on this forum are balanced with respect when warranted and trolling when warranted. When folks post 'nothing works' or 'there's no support' or 'my dudu stinks' - I'm just trolling their troll. I own it 🙂

Mikescotland

picasso1850 I think I will keep it, with custom canbox is getting there.
So far the worst part of it is the phone application. Not synchronising, missing recents, god knows how to add favourites and in the UK operators follow strange incoming caller ID with 0xxx for calls and +44xxx for texts, WhatsApp gives 44xxx and I've got all contacts as +44xx which renders recognition useless. I wish there was another alternative to that app.

Matthieu614

Thanks all for your investigations 👏

@dudu-lai so could it implemented someway in the future ? Or through a OBD2 dongle communicating with the host ?

Mikescotland

Matthieu614 not thought obd2 dongle. I have built an esp32 canbus decoder, programmed to clio III can messages and mapped relevant commands to Dudu unit.
Cost of the hardware is around 10 USD. I'm happy to provide all documentation if anyone wants. This also works in Nissans from around 2011 (they used same ECUs as Renault).
I doubt any manufacturer would create canbox for clios (or meganes from this period) as we have two canbuses in the car and their priority is SWC buttons not engine data.

Matthieu614

I'll be happy to look at the code as a software développer 😊

Mikescotland

Matthieu614 I'll post it here once I'm back at home. I've got more canbus messages decoded, however they can't be passed to HU for now, as they are very secretive of uart messages unit accepts.
So far working:

steering wheel angles
handbrake on / off
doors open / close
RPM
outside temperature
odometer

Possible but not implemented as duplicate of my obdII elm dongle:

coolant temperature
battery voltage
speed

Decoded but unknown headunit uart commands:

lights - all of them Inc fog lights
indicators

Not possible in clio III:

fuel remaining (requires command to ecu and puts the whole ecu in diagnostic mode, there must be direct canbus connection between instrument panel and ecu, as the ecu is reporting remaining fuel in liters over canbus to instrument panel)

Cannot test air conditioning as my car has manual one (on/off) and aircon ecu is not present.

Mikescotland

Matthieu614

#include <ESP32-TWAI-CAN.hpp>
#include <HardwareSerial.h>
#include <cmath>

// =========================================================================
// Configuration
// =========================================================================
#define CAN_TX 5
#define CAN_RX 4
const int CAN_ID_STATUS_DOORS_TEMP = 0x60D;
const int CAN_ID_ODOMETER = 0x5FD;
const int CAN_ID_RPM = 0x181;
const int CAN_ID_STEERING = 0x0C2;
const int CAN_ID_PARKING_BRAKE = 0x5C5;
const int CAN_BAUD_RATE = 500000;

// --- Steering Angle Calibration ---
const int STEERING_RAW_LEFT = 107;
const int STEERING_RAW_RIGHT = 148;
const int STEERING_MAPPED_LEFT = -540;
const int STEERING_MAPPED_RIGHT = 540;

const int UART_TX_PIN = 17;
const long UART_BAUD_RATE = 38400;
HardwareSerial UartPort(1);

const uint8_t CMD_STATUS = 0x41;
const uint8_t CMD_STEERING_WHEEL = 0x26;
const uint8_t SUB_CMD_DOOR_INFO = 0x01;
const uint8_t SUB_CMD_VEHICLE_INFO = 0x02;

const long VEHICLE_INFO_SEND_INTERVAL_MS = 500;
const long STEERING_SEND_INTERVAL_MS = 200;
const long STATUS_SEND_INTERVAL_MS = 250; 

// --- Bitmasks for the status byte ---
const uint8_t MASK_PARKING_BRAKE_ON = 0x20;

// =========================================================================
// Global Variables
// =========================================================================
CanFrame rxFrame;

int outsideTemperature = 15;
uint32_t odometerValue = 0;
uint16_t engineRpm = 0;
int16_t steeringAngleMapped = 0;
uint8_t currentDoorStateMask = 0;
bool isParkingBrakeOn = false;

unsigned long lastVehicleInfoSendTime = 0;
unsigned long lastSteeringSendTime = 0;
unsigned long lastStatusSendTime = 0;

// =========================================================================
// Helper Functions
// =========================================================================
void sendCanboxMessage(uint8_t cmd, uint8_t* data, uint8_t len) {
    uint8_t sum = cmd + len;
    for (int i = 0; i < len; i++) { sum += data[i]; }
    uint8_t checksum = sum ^ 0xFF;

    uint8_t finalFrame[len + 4];
    finalFrame[0] = 0x2E;
    finalFrame[1] = cmd;
    finalFrame[2] = len;
    memcpy(&finalFrame[3], data, len);
    finalFrame[3 + len] = checksum;
    
    UartPort.write(finalFrame, sizeof(finalFrame));
}

void sendStatusByteCommand(uint8_t doorStateMask) {
    uint8_t finalStateMask = doorStateMask;
    if (isParkingBrakeOn) {
      finalStateMask |= MASK_PARKING_BRAKE_ON;
    }
    uint8_t dataPayload[] = {SUB_CMD_DOOR_INFO, finalStateMask};
    sendCanboxMessage(CMD_STATUS, dataPayload, sizeof(dataPayload));
}

void sendVehicleInfoCommand() {
    uint16_t temp_encoded = outsideTemperature * 10;
    uint8_t dataPayload[13] = {
        SUB_CMD_VEHICLE_INFO,
        (uint8_t)(engineRpm >> 8), (uint8_t)(engineRpm),
        0, 0, 0, 0,
        (uint8_t)(temp_encoded >> 8), (uint8_t)(temp_encoded),
        (uint8_t)(odometerValue >> 16), (uint8_t)(odometerValue >> 8), (uint8_t)(odometerValue),
        0
    };
    sendCanboxMessage(CMD_STATUS, dataPayload, sizeof(dataPayload));
}

void sendSteeringAngleCommand() {
    uint8_t dataPayload[2] = {(uint8_t)(steeringAngleMapped), (uint8_t)(steeringAngleMapped >> 8)};
    sendCanboxMessage(CMD_STEERING_WHEEL, dataPayload, sizeof(dataPayload));
}

// =========================================================================
// SETUP
// =========================================================================
void setup() {
  // Serial.begin(115200); // Debugging disabled
  UartPort.begin(UART_BAUD_RATE, SERIAL_8N1, -1, UART_TX_PIN);
  ESP32Can.setPins(CAN_TX, CAN_RX);
  ESP32Can.setSpeed(ESP32Can.convertSpeed(CAN_BAUD_RATE));
  ESP32Can.begin();
}

// =========================================================================
// LOOP
// =========================================================================
void loop() {
  if (ESP32Can.readFrame(rxFrame)) {
    switch (rxFrame.identifier) {
      
      case CAN_ID_STATUS_DOORS_TEMP:
        if (rxFrame.data_length_code >= 5) {
          outsideTemperature = round((float)rxFrame.data[4] - 40.0);
          uint8_t byteA = rxFrame.data[0];
          uint8_t newDoorStateMask = 0;
          if (byteA & (1 << 4)) newDoorStateMask |= 0b00000001; // Driver (A.5)
          if (byteA & (1 << 3)) newDoorStateMask |= 0b00000010; // Passenger (A.4)
          currentDoorStateMask = newDoorStateMask;
        }
        break;

      case CAN_ID_ODOMETER:
        if (rxFrame.data_length_code >= 3) {
          uint32_t rawOdo = ((uint32_t)rxFrame.data[0] << 16) | ((uint32_t)rxFrame.data[1] << 8) | rxFrame.data[2];
          odometerValue = rawOdo / 16;
        }
        break;

      case CAN_ID_RPM:
        if (rxFrame.data_length_code >= 2) {
          uint16_t rawRpm = ((uint16_t)rxFrame.data[0] << 8) | rxFrame.data[1];
          // CORRECTED: RPM value is divided by 8 to get the real value
          engineRpm = rawRpm / 8;
        }
        break;

      case CAN_ID_STEERING:
        if (rxFrame.data_length_code >= 1) {
          int rawAngle = rxFrame.data[0];
          steeringAngleMapped = map(rawAngle, STEERING_RAW_LEFT, STEERING_RAW_RIGHT, STEERING_MAPPED_LEFT, STEERING_MAPPED_RIGHT);
        }
        break;
      
      case CAN_ID_PARKING_BRAKE:
        if (rxFrame.data_length_code >= 1) {
          isParkingBrakeOn = (rxFrame.data[0] & (1 << 2)) == 0;
        }
        break;
    }
  }

  // --- Handle Timed Sends ---
  unsigned long currentTime = millis();
  
  if (currentTime - lastVehicleInfoSendTime >= VEHICLE_INFO_SEND_INTERVAL_MS) {
    lastVehicleInfoSendTime = currentTime;
    sendVehicleInfoCommand();
  }

  if (currentTime - lastSteeringSendTime >= STEERING_SEND_INTERVAL_MS) {
    lastSteeringSendTime = currentTime;
    sendSteeringAngleCommand();
  }
  
  if (currentTime - lastStatusSendTime >= STATUS_SEND_INTERVAL_MS) {
    lastStatusSendTime = currentTime;
    sendStatusByteCommand(currentDoorStateMask);
  }
}

Mikescotland

Matthieu614 Decided to rework everything and use Toyota RAV4 protocol.
Take a look:
https://forum.dudu-auto.com/d/775-rfi-canbus-decoder-w-best-support-and-its-uart-byte-sequence-mappings/61

mesyounes

Mikescotland
Hello, thank you for your excellent work. I would like to know if it is possible to get the code with coolant temperature, battery voltage, speed, and the 5 doors, and which CAN bus are you connected to? SWC work ? Thank you.

Matthieu614

Looks nice ! So what do I need to replicate on my side ? I imagine that i have to swap canbox but does steering wheel button would still work ? Any way bravo for what you've accomplished so far 👏

Mikescotland

Matthieu614 I abandoned the VW protocol and with help of @MihaiFlorin who provided patiently logs pretty much reverse engineered new Toyota canbox protocol. Why? Because VW has just a few data while Toyota also shows nice icons for lights etc on the status bar and by emulating it, Dudu thinks I've got Toyota, but in fact it's a Clio.
For a few days I left SWC now alone, as I said before clio III, megane II (possibly Megane III) and Nissan Juke from around 2011 (possibly also all Nissans from that time like Micra etc) have two canbus lines, engine / body main and multimedia.
So, the engine / body part is actually finished and I'll update this post later (working all doors, all lights, steering angle, parking brake, RPM, speed, outside temperature and probably remaining range). Seatbelt status is broken in latest Raise Toyota protocol and shows all the time ON, so not implemented so far. Not available in clio III (but protocol decoded): gears, EV battery left, trip mileage A and B and TPMS.
Now, for the SWC I need to build another decoder connected to multimedia can and feed translated UART messages to the main canbox to be passed alongside with main UART payloads.
All hardware cost is less than 15EUR and SWC is easier as we know Toyota SWC commands to HU so no real reverse engineering needed.

Cris

Mikescotland I have a renault clio IV and i have been try to replicate your process but its doing my head in can you please share with me what ESP device you used and the code please.

Mikescotland

Cris no worries. I'll do it tomorrow, as away from home now.
I'm not sure if the Canbus messages are the same in clio iii and iv though.

Mikescotland

As promised protocol
https://drive.google.com/file/d/1iFL_Nui0X3n9P1Bsn-8NDJzWbIL6fmh6/view?usp=drivesdk
https://drive.google.com/file/d/1iFQtRCPRPOZsFAjxb1eWVp3IcNeYncvQ/view?usp=drivesdk

Mikescotland

mesyounes what car?

mesyounes

Mikescotland Clio 3 phase 2

Mikescotland

mesyounes tomtom navi or just radio with the small amber screen?
I've got Tom Tom navi and not sure if the SWC canbus messages will be the same as just radio and screen.
Engine data will be the same.
I'll put it all together and post it.
I'm using ObdII socket as both canbuses (multimedia and engine) are present on it in Renault.
Coolant temperature and battery voltage is present on Renault canbus but the command to the headunit is unknown (yet) for me. So for now it's without it (dudu doesn't show this values from canbus on the status bar anyway but from obd BT adapter only).

mesyounes

Mikescotland Radio and screen with temp
To give you more information, I have a "simple soft" CANbus. The SWC works, but I have no information about the car's doors, temperature, reverse gear, etc.
Is it possible to connect two CANbuses? one for SWC and another for infos ?
Please, can you give me your OBD wiring diagram?
Thank you very much and have a nice evening.

Mikescotland

How is Simple Soft connected to the car? Multimedia CANBUS?

I am attaching a dirty schematic for my adaptor - I wasn't expecting to share it - it was just to design the PCB and it will be delivered in a few days. I used two ESP32 (big ones, as I had two spare just getting dust, it fine to use ESP32 mini). One ESP32 is for multimedia CAN for SWC, one ESP32 is for engine/body CAN, SWC is passing UART messages to main ESP32, and from this one it goes to the HU (that is to connect two UART lines to one UART input in the HU). There is also a header for a 1.8 inch TFT as my car is a diesel and I have a DPF so I'd like to know when it's regenerating, so I keep driving.
12V to power it comes from ACC line. ILLUMI input was meant to be for switching display to night mode, but at the end of the day I used CANBUS message for lights for this, so it can be used and programmed for any 12V trigger.
https://drive.google.com/file/d/1jZfsXzPao81jlkQmT2NBGCT_h3H_-lT7/view?usp=sharing
Once the board(s) arrive, I will test it and refine the code for ESP32 CAN and SWC and publish it.
Renault OBD pinout is here: https://pinoutguide.com/CarElectronics/renault_obd2_diag_pinout.shtml with multimedia canbus also indicated on pins 12/13.
You would need the following from Renault canbus:
0x60D - Status, Doors & Temperature
This is a multi-purpose message containing information about vehicle status, lights, doors, and ambient temperature. It expects a data length of at least 5 bytes.
Bytes 0-2: A 24-bit field holding various status flags.
Bit 11: High beams are on.
Bit 13: Left indicator is active.
Bit 14: Right indicator is active.
Bit 17: Headlights are on.
Bit 18: Parking lights are on.
Bit 19: Passenger door is open.
Bit 20: Driver's door is open.
Bit 21: Rear right door is open
Bit 22: Rear left door is open
Bit 23: Boot is open.

Byte 4: Contains the outside temperature. The value is calculated by subtracting 40 from the byte's value (

data[4] - 40.0f).

0x5FD - Odometer

This message provides the vehicle's total distance traveled. It expects a data length of at least 3 bytes.
Bytes 0-2: A 24-bit integer representing the odometer reading. The final value in kilometers is obtained by combining the bytes and dividing by 16 (
((data[0] << 16) | (data[1] << 8) | data[2]) / 16).

0x181 - Engine RPM

This message contains the current engine speed. It expects a data length of at least 2 bytes.

Bytes 0-1: A 16-bit integer representing the engine revolutions per minute. The value is formed by concatenating the two bytes (

(data[0] << 8) | data[1]).

0x0C2 - Steering Wheel Angle

This message relays the raw angle of the steering wheel. It expects at least 1 byte of data.

Byte 0: A raw, single-byte value for the steering wheel's position. This value is then mapped from its raw range to a final angle in degrees.

0x5C5 - Parking Brake Status

This message indicates whether the parking brake is engaged. It uses at least 1 byte of data.

Byte 0: A status byte where bit 2 indicates the brake status. The parking brake is considered

ON when this bit is 0.

0x354 - Speed & Brake Pedal
This message provides the vehicle's current speed, a trip distance, and the brake pedal status. It requires a data length of at least 5 bytes.

Bytes 0-1: A 16-bit value for vehicle speed. The final value is calculated by multiplying the raw integer by 0.01 (

((data[0] << 8) | data[1]) * 0.01f).

Bytes 2-3: A 16-bit value for a trip counter. The final distance is calculated by multiplying the raw integer by 0.1 (

((data[3] << 8) | data[2]) * 0.1f).

Byte 4: A status byte where bit 4 indicates if the brake pedal is being pressed ((data[4] & (1 << 4)) != 0).

mesyounes

Mikescotland My "simple soft" is connected to multimedia CANBUS.

Your project looks very interesting. I'll wait for the results and I hope you'll share the code with us.
Have a good day.

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