Schematic and Expansion Connectors¶
Are you ready to hack your CodeBot?
Here is where you’ll find all the information you need!
Expansion Connectors¶
Note: The two connectors bring out an identical set of signals.
This means that if you make an expansion board that plugs into both connectors, it can be rotated 180° and work the same!
Or, you can make two small boards that each have access to all the expansion pins.
- Mechanical
The connectors are made to line up with standard low-cost prototyping PCBs.
They are 0.1” pitch (spacing between pins)
They are spaced apart 2.4”
- Electrical
I2C bus
SPI bus
UART tx/rx
GPIO / ADC / UART (2)
Regulated 3.3V
Battery voltage (6V when fresh)
(See schematic for details of connection to STM32)
Software Interface¶
CodeBot CB2 is running version 1.11 of Micropython.
Documentation for using GPIO and many of the internal STM32 hardware peripherals can be found here: http://docs.micropython.org/en/v1.10/library/machine.html
CodeBot CB3 is running CircuitPython. Documentation for that is here: https://docs.circuitpython.org/en/latest/shared-bindings/index.html
The botcore library documentation has links to the source code which provides examples of using I/O, ADCs, and PWM.
Schematic Diagram¶
(detailed for CB2. See PDF of CB3 below for differences)
A schematic diagram is an electrical engineering drawing that shows all the components and interconnections on a piece of electronic hardware.
- Page 1 highlights
STM32 microcontroller
USB input connector and protection diodes
Dual H-bridge motor driver
Expansion connectors
Speaker
Debug headers
- Page 2 highlights
LED driver shift-registers
USER, LS, and Prox LEDs
Line Sensors
Proximity Sensors
Wheel Encoders
Pushbuttons
Accelerometer
- Page 3 highlights
Power supply
ON/OFF switch
