>> https://www.waveshare.com/w/upload/e/e2/2-CH-CAN-FD-HAT-Schematic.pdf >> >> Grmpf :/ >> >>> This means that can1 cs is connected to pi header pin 26 >> >> Both of rpi's SPI host drivers prefer to use GPIO chip selects by default, as >> native chip selects have some limitations. And all three mcp251xfd overlays use >> GPIO chip selects, this means you can use any free GPIO in the system for the >> SPI chip select. >> >> Marc >> > > It took me a while to realize but those pin numbers on the PCB are > WPI := WiringPi numbers, not header pin numbers and not BCM pin numbers. > > The schematics also has the WPI column in the lower left section. > > https://pinout.xyz/pinout/wiringpi# > > -- > Patrick > It may be a blunt guess, but according to page 99 https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2711/rpi_DATA_2711_1p0.pdf Pin 26 is pulldown. So it works if it remains unused because the pin is input with pulldown thus the chip is selected by default. I don't know if the CE pin can actually work if there is no matching alt function in pinselect register. -- Patrick
