I have a problem with Raspberry Pi 3b+.
I need to connect two DACs (MCP4911) to SPI bus 1. The two DACs are expected to output the different DC voltage level.
However, I found that when I connected the SCK (pin40, BCM21) to two DACs (DAC A use SPI1CE2, DAC B uses SPI1CE1) at the same time, then both two DACs will not work properly (i.e. the output remains unchanged, no matter what numerical values I send). If I disconnected the CLK to DAC B, then the data can be properly sent to DAC A.
I want to know whether it is a hardware problem or a coding problem. How should I control two DACs with Python?