M-Bus

1.Introduction

M-Bus is a stacking expansion bus design (2x15P@2.54mm) used in the M5Stack stacking series products (Module, Base). The Core series main control devices can quickly stack different modules via M-Bus to achieve functional expansion.

2.PinMap

The M-Bus defines some power-related connections (GND, 5V, 3V3, BAT, etc.) at certain fixed positions, making it easier to be compatible with different modules and main control devices. The other IO pins are adjusted based on the actual situation, so when stacking expansion modules, the program may need to be adjusted according to the actual IO being used.