Initial Design of BBBmicro
(BBBmicro is a reduced version of BBBmini for use with PocketBeagle, using SMD components and SMD connectors).
The more compatibility BBBmicro has with the BBBmini PCB, the better. So the same ports, port numbers and pin numbers will be used whenever possible. All connectors will be of the JST GH series (https://www.digikey.com/catalog/en/partgroup/gh-series/8397) for reliability and compatibility with the ecosystem of accessories for pixhawk2 & pixracer flight controllers.
I think we need at minimum:
- +5V Power input (P11 pins: 5V IN, GND),
- UART for GPS (P10 pins: TX, RX, GND, 3.3V, 5V),
- UART for Telemetry (P7 pins: TX, RX, GND, 3.3V, 5V),
- I2C for 2nd Compass (P20 pins: SDA, SCL, GND, 3.3V, 5V),
- I2C for OLED screen or accessories (P15 pins: SDA, SCL, GND, 3.3V, 5V),
- PPMSUM RC input (P4 pins: RCIN, GND, 3.3V, 5V),
- 4 x PWM motor outputs (or should I make 6?) (P16 pins: GND, PWM_OUT1, PWM_OUT2, PWM_OUT3, PW_OUT4),
- AUX port (Voltage Monitor signal?, Current Monitor signal?, Buzzer, LED).
BBBmicro will try to use the exact same sensors as BBBmini so it will be easier for Mirkix to maintain software for both boards.
Connectors not available in BBBmicro compared to BBBmini:
- P1 & P2 "RC Output" 12 channel connector (because rarely used?)
- P14 CAN bus (because rarely used)
- P19 Ultrasonic Range Finder (because too unreliable)