@alessandro-giusti said in External trigger on duet 3 6hc:

I bought and connected the sammy-c21 card, followed the guide and connected the card in can bus with duet 3 6hc.
The sammy-c21 communicates with duet, with the command m115 I have the following answer: m115 b124
Duet SAMMYC21 firmware version 3.3beta2 (2021-03-10 10:08:39).

Are there any special pins I need to use for a momentary button or is any pin okay?

When I declare them in the config.g do I have to specify the bus address of the card?

Thanks in advance.

Here's an extract from the pin table for the standard SAMMYC21 build in firmware 3.3beta:

Nx, nullptr }, // PA00 not on board Nx, nullptr }, // PA01 not on board Nx, "temp0" }, // PA02 Nx, "temp1" }, // PA03 4, "pa04" }, // PA04 5, "pa05" }, // PA05 6, "pa06" }, // PA06 7, "pa07" }, // PA07 Nx, "pa08" }, // PA08 Nx, nullptr }, // PA09 driver EN Nx, nullptr }, // PA10 driver DIR Nx, nullptr }, // PA11 driver STEP 12, "pa12" }, // PA12 13, nullptr }, // PA13 accelerometer INT1 Nx, nullptr }, // PA14 crystal Nx, nullptr }, // PA15 crystal Nx, nullptr }, // PA16 SPI Nx, nullptr }, // PA17 SPI Nx, nullptr }, // PA18 SPI 3, "pa19" }, // PA19 Nx, "pa20" }, // PA20 Nx, "pa21" }, // PA21 Nx, nullptr }, // PA22 I2C Nx, nullptr }, // PA23 I2C Nx, "pa24" }, // PA24 Nx, "pa25" }, // PA25 Nx, nullptr }, // PA26 not on chip Nx, nullptr }, // PA27 CAN transceiver standby Nx, nullptr }, // PA28 LED 0 Nx, nullptr }, // PA29 not on chip Nx, nullptr }, // PA30 swclk Nx, nullptr }, // PA31 swdio Nx, nullptr }, // PB00 not on chip Nx, nullptr }, // PB01 not on chip Nx, nullptr }, // PB02 USB interface (SERCOM5 pad 0) Nx, nullptr }, // PB03 USB interface (SERCOM5 pad 1) Nx, nullptr }, // PB04 not on chip Nx, nullptr }, // PB05 not on chip Nx, nullptr }, // PB06 not on chip Nx, nullptr }, // PB07 not on chip 8, "pb08" }, // PB08 9, "!^button0" }, // PB09 button recognised by bootloader

You can use any pin that has an interrupt number in the first column (i.e. not "Nx") and a name in the second column. So 9 pins available in total. If you use PB09 then it must not be grounded when power is applied unless you want the SAMMYC21 to reload the firmware over CAN.

You do need to specify the CAN address, also you will need to enable the pullup resistor unless you add an external one. For example: "^124.pb08".