Setting CAN Bus address by GPIO

1

Hey community,

I use the old odrive 3.6 dual Drive SW version 0.5.6
and I want to change the odrive CAN Bus address by setting a GPIO pin high or low (like i2 chips).
Unfortunately I am not too firm with odrive firmware.
So far I set dev0.config.gpio8_mode = GpioMode.DIGITAL_PULL_UP which I want to use as address switch.

the code so far:

    bool can_add_pin_state = get_gpio(8).read();
    if(axis.config_.dir_gpio_pin ==0){ // AXIS0
        if(can_add_pin_state)
            axis.config_.can.node_id = 2;
        else
            axis.config_.can.node_id = 4;
    }
    else{ //AXIS1
        if(can_add_pin_state)
            axis.config_.can.node_id = 3;
        else
            axis.config_.can.node_id = 5;
    }

The question is, where in Firmware I should add the “address switching” code to immediately change the CAN address during runtime if the GPIO State change.

Would be nice to get some help THX

2

Changing it during runtime is going to be a pretty complicated endeavor. All the CAN stuff is only initialized during boot - so you’d likely have to check / set CAN address on ODrive power-on or reboot only - e.g. in the board initialization setup.

3

Thanks, for your answere,
But for some reason I can change the CAN address during runtime using the USB Interface without save configuration or reboot
It uses the new address imidetly
So i think it should be possible

4

if someone needs. Not nice but it works

void CANSimple::handle_can_message(const can_Message_t& msg) {
// Frame
// nodeID | CMD
// 6 bits | 5 bits
uint32_t nodeID = get_node_id(msg.id);

for (auto& axis : axes) {

    if ((axis.config_.can.node_id == nodeID) && (axis.config_.can.is_extended == msg.isExt)) {
           //TODO NOT WORKING
        bool can_add_pin_state = get_gpio(8).read();
        if(axis.config_.dir_gpio_pin ==0){ // AXIS0
            if(can_add_pin_state)
                axis.config_.can.node_id = 2;
            else
                axis.config_.can.node_id = 4;
        }
        else{ //AXIS1
            if(can_add_pin_state)
                axis.config_.can.node_id = 3;
            else
                axis.config_.can.node_id = 5;
        }

        do_command(axis, msg);
        return;
    }
}

}