Rick has some integrated sensors that can be accessed through its API or the Python library
MMA8452Q 3-axis, 12/8 bit accelerometerconnected on the 1st I2C bus. By convention, the axes of the accelerometer are re-mapped in the API from their manufacturer assignments onto the standard robot frame of reference (x forward, y laterally left, z vertically up). These are marked on the PCB.
A 0.1 Ω 1206 resistor (Schematic ref. R7 to R14) is attached from the Servo low-side to ground, and then to a GPIO on U1 for all motor channels except channel 9 (used for the Eyes). This permits motor current sensing, as a proxy for exertion/force/torque.
0x51
5V input, logic 3V3 (not 5V tolerant)
https://public.robotical.io/Schematics/VCNL4200_Board/VCNL4200_breakout_schematic.pdf
26mm × 13.5mm × 13mm (with connector) Cable & Connector Approx 22cm long, JST XH 5 pin (10mil spaced) on board to 2 × 3 female pin header