Simply DIY ESP32 CAN bus

Minerillo

Hello everyone,

I'm looking to read the CAN bus on my Duke 790 with an ESP32, and after reading so many posts, I'm completely confused.

First, I'm not sure which module to add to the ESP32, the MCP2515 or the SN65HVD230. I understand that the latter is better and that it would work well with the ESP32 itself.

On the other hand, which is better, Bluetooth or Wi-Fi?

Can anyone shed some light on this for me? I also assume that in the esp32 code, I will be able to give it a different refresh rate depending on the channel (for example, 1Hz for engine temperature and 25Hz for front brake pressure). I have a list of channels and formulas for my motorcycle. I guess to improve the refresh rate, the ESP32 should only pass these channels to RaceChrono, right?

I've seen many libraries on GitHub, all different, and that's what confuses me.

I want to have everything clear before ordering the hardware. The power supply will be from the Duke's own 6-pin connector (CAN H, CAN L, GND, and 12V), so I'll put a step-down to 5V for the ESP32.

Thanks everyone, and sorry for the mess.

aol

I'd use Bluetooth LE as there's better API available.

Implement the Bluetooth LE API, encode your channels to the payload as you wish (or just pass the selected CAN-Bus packets as-is like in my example device), and then decode them in the "CAN-Bus" channels that can be configured in the Vehicle Profile part of the app.

Minerillo

aol

Good afternoon, Aol. I just saw in the code I created with Gemini that the RaceChrono.h library in the include is the one you developed in 2019. Is it up to date? Will it work in my code?

Thank you!

Minerillo

I have been gathering information and, together with Gemini, I have written some code. Now I need to test it when I receive the esp32 and the SN65HVD230.

I am leaving the code here in case you see any errors or anything else. Thank you!!!

#include <RaceChrono.h>
#include "driver/twai.h"

// --- CONFIGURACIÓN DE PINES ---
#define CAN_TX_PIN 5
#define CAN_RX_PIN 4

// --- INICIALIZACIÓN DE RACECHRONO ---
RaceChrono rc("KTM 790 DIY Track");

// IDs de canales para RaceChrono
int ch_rpm, ch_tps, ch_gear, ch_v_front, ch_v_rear;
int ch_brk_f, ch_brk_r, ch_lean, ch_pitch;
int ch_abs_act, ch_mtc_act, ch_temp_eng;

void setup() {
Serial.begin(115200);

// 1. DEFINICIÓN DE CANALES EN LA APP
ch_rpm      = rc.addCanChannel("RPM", "rpm", 20);
ch_tps      = rc.addCanChannel("Throttle Position", "%", 20);
ch_gear     = rc.addCanChannel("Gear", "", 5);
ch_v_front  = rc.addCanChannel("Wheel Speed Front", "km/h", 10);
ch_v_rear   = rc.addCanChannel("Wheel Speed Rear", "km/h", 10);
ch_brk_f    = rc.addCanChannel("Brake Pressure Front", "bar", 50);
ch_brk_r    = rc.addCanChannel("Brake Pressure Rear", "bar", 20);
ch_lean     = rc.addCanChannel("Lean Angle", "deg", 25);
ch_pitch    = rc.addCanChannel("Pitch (Wheelie)", "deg", 25);
ch_abs_act  = rc.addCanChannel("ABS Intervention", "", 50);
ch_mtc_act  = rc.addCanChannel("MTC Intervention", "", 50);
ch_temp_eng = rc.addCanChannel("Engine Temp", "C", 1);

// 2. CONFIGURACIÓN DRIVER CAN (TWAI) - 500 kbps
twai_general_config_t g_config = TWAI_GENERAL_CONFIG_DEFAULT((gpio_num_t)CAN_TX_PIN, (gpio_num_t)CAN_RX_PIN, TWAI_MODE_LISTEN_ONLY);
twai_timing_config_t t_config = TWAI_TIMING_CONFIG_500KBITS();
twai_filter_config_t f_config = TWAI_FILTER_CONFIG_ACCEPT_ALL();

if (twai_driver_install(&g_config, &t_config, &f_config) == ESP_OK && twai_start() == ESP_OK) {
    Serial.println("CAN Bus: Sistema iniciado correctamente");
} else {
    Serial.println("CAN Bus: Error de inicio");
}

rc.begin(); // Iniciar Bluetooth BLE
Serial.println("Bluetooth: Esperando conexión de RaceChrono...");

}

void loop() {
twai_message_t msg;

// Procesar mensajes del bus CAN
while (twai_receive(&msg, 0) == ESP_OK) {
    
    switch (msg.identifier) {
        
        case 0x120: // RPM y Modo
            rc.updateCanChannel(ch_rpm, (msg.data[0] << 8) | msg.data[1]);
            break;

        case 0x129: // Marcha
            rc.updateCanChannel(ch_gear, msg.data[0]); 
            break;

        case 0x12A: // Acelerador (TPS)
            rc.updateCanChannel(ch_tps, msg.data[0] / 2.55);
            break;

        case 0x12B: // Ruedas e IMU (Lean/Pitch)
            rc.updateCanChannel(ch_v_rear, ((msg.data[0] << 8) | msg.data[1]) / 10.0);
            rc.updateCanChannel(ch_v_front, ((msg.data[2] << 8) | msg.data[3]) / 10.0);
            rc.updateCanChannel(ch_lean, (int8_t)(msg.data[4] - 128));
            rc.updateCanChannel(ch_pitch, (int8_t)(msg.data[5] - 128));
            break;

        case 0x290: // Frenos y ABS
            rc.updateCanChannel(ch_brk_f, ((msg.data[0] << 8) | msg.data[1]) / 10.0);
            rc.updateCanChannel(ch_brk_r, ((msg.data[2] << 8) | msg.data[3]) / 10.0);
            // Si el byte 4 cambia al frenar fuerte, es el flag de ABS
            rc.updateCanChannel(ch_abs_act, (msg.data[4] > 0 ? 1 : 0));
            break;

        case 0x450: // Control de Tracción (MTC)
            rc.updateCanChannel(ch_mtc_act, (msg.data[0] > 0 ? 1 : 0));
            break;

        case 0x540: // Temperaturas
            rc.updateCanChannel(ch_temp_eng, msg.data[0] - 40);
            break;
    }
}

rc.run(); // Mantener conexión Bluetooth

}

aol

Minerillo I haven't touched any related code since I first made my proof-of-concept device 🙂

Minerillo

aol

I see... about what I posted, do you think it will work?

Thanks!!

aol

Minerillo No idea whats happening there 😃