They have a stripped-down serial port that does shift bits out that software serial does all on the cpu.
See about connecting through SPI if you have the pins, reset can be disabled to free 1 pin, SPI needs 4.
They have a stripped-down serial port that does shift bits out that software serial does all on the cpu.
See about connecting through SPI if you have the pins, reset can be disabled to free 1 pin, SPI needs 4.