04 / SYSTEM2026

LeRobot 6-DOF Arm — Teach & Replay

6-DOF teach-and-replay arm on serial-bus servos

No microcontroller. Six servos on one serial bus, and a bus that sometimes lied.

Hardware / Serial bus / Python · STATUS: PHYSICAL

A hand physically guiding the 3D-printed 6-DOF arm while a laptop shows live per-servo position, angle, and status feedback
KINESTHETIC TEACH — LIVE SERVO FEEDBACK ON SCREEN

SYSTEM SHEET

SYSTEM
6-DOF 3D-printed arm, no microcontroller — host PC talks straight to the bus
SERVOS
6× Feetech ST3215 serial-bus servos, daisy-chained on a Waveshare driver board
CONTROL
Python, 3 threads at 50 Hz — read, control, record
MODE
Kinesthetic teach & replay: grab the arm, move it, play it back
DEBUGGING
Intermittent bus faults chased at the protocol level — no firmware to blame

MY SCOPE

  • Adapted the open LeRobot arm design — printed and assembled the hardware
  • Wrote the ST3215 serial-bus control stack: 3 threads at 50 Hz
  • Kinesthetic teach-and-replay recorder
  • Protocol-level debugging of intermittent bus faults

CONNECTED WORK