XIAO ESP32S3 TWAI / CANBUS without "XIAO CAN Bus Expansion Board"

thankthemaker · August 9, 2023, 5:24pm

Hello,

does anyone know if the XIAO ESP32S3 can use the TWAI interface without the “XIAO CAN Bus Expansion Board”. I know that the ESP32S3 supports TWAI and I’m wondering if it’s possible to use it with the XIAO and a CAN-transceiver (like the SN65HVD232) only. I did some simple tests and I saw that twai_driver_install() and twai_start() returned ESP_OK, but I was not able to send or receive any CAN messages.

I used the code from this gist for testing

gist.github.com

https://gist.github.com/thankthemaker/9b8565c904f6351cdba5d5f0c4c1aac6

XIAO_ESP32S3_TWAI_Test.ino

#include "driver/twai.h"

twai_message_t rx_frame = {};
gpio_num_t tx = GPIO_NUM_3;
gpio_num_t rx = GPIO_NUM_4;

void setup() {
    delay(2000);
    gpio_reset_pin(rx);
    gpio_reset_pin(tx);

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It have a test circuit that does work on a WEMOS D1 Mini ESP32 and on an ESP32 Dev Board.
Running on the XIAO the code installs and starts the driver successfully but fails when transmitting packages. It also does not receive any messages from the bus.

Does anyone know how to make TWAI work without “the Expansion Board”?

davidcyr2000 · February 1, 2024, 5:08pm

Did you ever get this working? I am trying to do the same with the XIAO ESP32C3.
Thanks for any further insight!