I have a project I want to use a Mega as master and some Uno's as slaves, I tried to look into SPI, but is seamed overly complicated. So now I'm think of using serial. one channel for each slave. So that would let me have 4 (?) slaves on one Mega.
I want to use I2C, but the slaves are connected to their own BMS-chip (BQ76940) via I2C, and they have fixed adress. So the Uno's can be on the same I2C net.
Any other protocol to consider?