> It may be a blunt guess, but according to page 99 > > https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm27 > 11/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 Do you suggest that the communication works with a permanent low on CS/CE? Without the CS/CE pin having edges you will not be able to send multiple commands. The driver is writing/reading multiple times when bringing up the chip. If you have a permanent low that will fail. So somehow the CS does generate the right edges. Thomas
