Apologies for what is likely a beginner’s question. I’ve acquired a Cubie A7A SBC and am just starting to get familiar with it. I would like to configure two I2C interfaces and one SPI interface; I am trying to understand and apply concepts Device Tree Source files, the DT Compiler, etc., but it’s not clear to me how to go about this.
Is there a program or procedure where I could specify the number and types of interfaces/devices or I/O/PWM pins I require, which would then:
a) determine whether the request is even feasible
b) if so, determine which pins should be assigned to which functions, and subsequently generate the necessary configuration data (presumably source files for the Device Tree Compiler dtc and the corresponding output for the bootloader)?
Thanks in advance for any advice and/or links regarding this topic! Best, Franta H.
P.S. The description of the various pin functions on the GPIO connector seems unclear or so - for instance:
a) 40 Pin GPIO Interface | Radxa Docs mentions that some pins have up to 9 different functions.
b) https://linux-sunxi.org/Radxa_Cubie_A7A - in the “Expansion ports” section, the pins of the 40-pin GPIO connector are listed according to their potential functions. The table shows that some pins can have as many as 10 different functions - that’s one more than mentioned in (a)!?