Serial API

Preliminary documentation. This product is in pre-launch preview; specifications and commands may change before shipping.

The arm appears as a USB serial device (115200 baud, 8N1). Each command is one line of JSON; each reply is one line of JSON.

Read status

{"cmd": "status"}

{"ok": true, "mode": "follow", "pos": {"height": 142, "depth": 80, "tilt": 6, "pan": -3},
 "user": {"present": true, "distance_mm": 612}, "fw": "1.2.0"}

Positions are millimetres (height, depth) and degrees (tilt, pan).

Move

{"cmd": "move", "height": 180, "tilt": 5, "speed": 15}

Omitted axes stay where they are. speed is mm/s (max 20). Moving manually switches the arm to manual mode.

Modes

{"cmd": "mode", "value": "follow"}

Presets

{"cmd": "preset.save", "slot": "stand"}
{"cmd": "preset.go", "slot": "sit"}

Slots: sit, stand.

Tracking tuning

{"cmd": "tracking", "deadband_mm": 40, "delay_s": 3, "distance_mm": 600}

Python example: stand at 2 pm

import json, serial, time

arm = serial.Serial("/dev/ttyACM0", 115200, timeout=1)

def send(**cmd):
    arm.write((json.dumps(cmd) + "\n").encode())
    return json.loads(arm.readline())

while True:
    if time.strftime("%H:%M") == "14:00":
        send(cmd="preset.go", slot="stand")
    time.sleep(30)

Errors

Errors reply with {"ok": false, "error": "<code>"}. Codes: bad_json, unknown_cmd, out_of_range, obstructed, overload.