during setting up navio2/rpi i i experienced “unable to open spi bus” 3 times - i set up a fresh image every time and it worked again; (i thought it was an issue related to raspi-config - since some options returned an error - and enabling spi again lead to i2c error message and then to a /sys/class/pwm/pwmchip0 -error )
yesterday after having that same problem again i installed a fresh sdcard - now i get the following message:
pi@navio:~ $ sudo ArduCopter-hexa -C /dev/ttyAMA0
Raspberry Pi 2 with BCM2709!
Init APM:Copter V3.4-dev (cce4f12e)
Free RAM: 262144
FW Ver: 120
load_all took 19us
Q��No INS backends availableopened: No such file or directory0 0 0 �
HMC5843: Could not detect version
MPU9250: unexpected WHOAMI 0x0
i don’t know what to do when i get the “Unable to open /dev/spidev0.1 - No such file or directory
SPIDriver: unable to open SPI bus”; So i tried raspi -config enabling SPI;
flashing a fresh image on my SD-card removes the error, but after “apt-get update&&upgrade” and reboot the error occurs again…
just testet it again:
before apt-get update&&upgrade:
after “apt-get update&&upgrade”
raspberrypi-firmware package seems to upgrade kernel (this is not expected at all. The package description says that it’s temporarily, though. I guess we’re at the Raspberry Pi Foundation’s mercy at the moment for a while).
We’ll see what can be do about it, though.
If you cannot wait, there’s a pretty simple hack. You need to backup a couple of files and overwrite the files that are getting modified during the upgrade