HexDrive2

Standalone EEPROM-side app source for Team RobotMad HexDrive2 boards.

What This Repo Contains

• hexdrive2.py: the MicroPython app that is compiled to .mpy, copied onto a hexpansion EEPROM, and run by BadgeOS as app.mpy.

The exported runtime class is HexDriveApp.

Current Scope

The current implementation is the BadgeBot-derived HexDrive app with support for:

• HexDrive2 EEPROM detection.
• Motor-only, servo-only, mixed motor/servo, and uncommitted HexDrive variants.
• Keep-alive shutdown to de-energise outputs if updates stop arriving.
• HexDrive2 helper controls for the distance-sensor XSHUT pin and sensor LED.

Building

Compile the EEPROM app with mpy-cross:

mpy-cross -v hexdrive2.py -o hexdrive2.mpy

The resulting hexdrive2.mpy should then be copied into the consuming app's EEPROM/ directory. When a host app writes that file to a hexpansion EEPROM it is renamed to app.mpy on the EEPROM so BadgeOS will discover it automatically.

Public API

The current HexDriveApp implementation exposes these control methods:

• set_power(state): enable or disable the HexDrive supply.
• set_motors((left, right)): set signed motor outputs in the range -65535..65535 for supported motor channels.
• set_servoposition(channel=None, position=None): set servo pulse positions; channels are logical servo channels, not always direct physical pin numbers.
• set_servocentre(centre, channel=None): adjust servo centre trim.
• set_freq(freq, channel=None, servo=False): adjust PWM frequency for either motor or servo channels.
• set_keep_alive(period_ms): change the watchdog timeout.
• set_dist_xshut(state): HexDrive2-only distance-sensor reset/power pin control.
• set_sensor_led(state): HexDrive2-only sensor illumination LED control.

Behaviour Notes

• PWM outputs are allocated lazily so unused channels do not consume PWM resources.
• The keep-alive watchdog is refreshed by set_motors() and set_servoposition() updates.

Intended Consumers

This repository is intended to be used as a git submodule by:

• BadgeBot
• HexManager

Those host apps are responsible for compiling hexdrive2.py to EEPROM/hexdrive2.mpy and deploying the artifact to the badge.