I think I have identified the cause of the issue.
It seems that the library I use for I2C with mpd_oled (https://www.airspayce.com/mikem/bcm2835/) is not compatible with the I2C interface provided by the kernel (which is presumably used by the DAC driver)
https://www.raspberrypi.org/forums/viewt...p?t=262589
I updated the BCM2835 library to the latest vesion recently to provide support for the RPi4, but looking at the diff now I can see that where there used to be calls to open /dev/i2c-1 etc, these are now gone. It may be that I had a modified version of the library that used the kernel interface for I2C, in which case I may be able to add this back in. I will take a look.
Adrian.
It seems that the library I use for I2C with mpd_oled (https://www.airspayce.com/mikem/bcm2835/) is not compatible with the I2C interface provided by the kernel (which is presumably used by the DAC driver)
https://www.raspberrypi.org/forums/viewt...p?t=262589
I updated the BCM2835 library to the latest vesion recently to provide support for the RPi4, but looking at the diff now I can see that where there used to be calls to open /dev/i2c-1 etc, these are now gone. It may be that I had a modified version of the library that used the kernel interface for I2C, in which case I may be able to add this back in. I will take a look.
Adrian.
