I've got the following issue: I've attached a display to my Raspi 3B by using the SPI interface. It has been working fine for months, but a couple of weeks ago, the display suddenly stopped working despite apparently getting enough current (the cathodes are glowing). I checked all cables and found nothing abnormal, so I used the spincl utility to send commands to the display:
pi@autoradio:/import/valen/autoradio/spincl $ sudo ./spincl -ib
pi@autoradio:/import/valen/autoradio/spincl $ sudo ./spincl -m3 -c9 -s0 -p0 1 0x14
Every time I tried this out, spincl simply stopped and had to be killed with ^C. So I connected pins 19 (MOSI) and 21 (MISO) to each other so that SPI should now talk to itself. No use: spincl stopped again!
SPI has been enabled in raspi-config all the time.
UPDATE: Upon recommentation of another user, I ran gpiotest on the naked Raspi. Here's the result:
pi@autoradio:/import/valen/autoradio $ sudo pigpiod
pi@autoradio:/import/valen/autoradio $ sudo ./gpiotest
[…]
Skipped non-user gpios: 0 1 28 29 30 31
Tested user gpios: 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Failed user gpios: None
What's going on here?