Colibri-3
Colibri-3 is a 3 slot carrier board, meant for Colibri MCU1 or Dragino LoRa ST.
I2C Addresses
TCA9548 = 0x70 ; Selects which I/O slot the I2C should be connected to.
MCU Slot
The MCU slot is made for a STM32L071 MCU, sourced from Dragino Technologies.
It can be programmed from the pin header on the Colibri-3
Expansion Slots
Each expansion slot can be communicated to with I2C or SPI.
The I2C is connected via an I2C MUX on the board, to avoid address conflicts.
The SPI has a 3 Chip Select demux (PA0, PA1, PA2) signals per slot, only allowing selection of 1 CS at a time.
Each slot has +3.3V, +5V and +12V power, and the 3.3 and 5 Volt can be individually controlled on/off from the MCU. The external power supply is also available for the expansion boards to utilize.
Finally, each slot has 4 pins going to the 4-pole screw terminals on the Colibri-3.
Power Supply
The Colibri-3 can be powered by AC (5-36V) or DC (7-55V). But some expansion (Colibri Triac-1 for now) boards require AC power, and if powered with DC, those boards will not work.
The device consumes very little power, typically well below 1 Watt. Expansion boards may consume maximum 200mA on each power rail, and that may increase the power consumption substantially. The on-board power supply can supply 3A on 5V and 1A on 3.3V.