Rot32

Hardware Requirements

• ESP32 board running MicroPython
• LSM303 accelerometer/magnetometer on I2C
• Generic H-bridge motor driver, sharing a ground with the ESP32
• A two-axis (azimuth/elevation) rotator

Wiring

Defaults from config.py for ESP32-S3

Signal	Pin
I2C SDA	GPIO8
I2C SCL	GPIO9
AZ+ / AZ- (PWM)	GPIO4 / GPIO5
EL+ / EL- (PWM)	GPIO6 / GPIO7

Install

1. Flash MicroPython from micropython.org/download for your module.
2. Edit config.py: set WIFI_SSID, WIFI_PASSWORD, and the pin numbers.
3. Copy the project files to the device, e.g. mpremote cp *.py *.html :.
4. Reset the board. The IP address is recorded in the log, readable at http://<device-ip>/api/log or over serial with SERIAL_LOGGING_ENABLED.

Web UI

Browse to http://<device-ip>/ for a simple control interface:

• Position: live azimuth/elevation readout, plus the current target while a move is in progress.
• Manual control: press-and-hold direction buttons plus a speed slider.
• Go To Position: numeric azimuth/elevation entry, plus Park and Reset.
• Motion Tuning: arrival window, arrival speed, slow-down distance, and acceleration.
• Calibration: declination, offsets, invert flags, axis selection, smoothing, and a magnetometer calibration wizard.

First-time setup

1. Pick the azimuth forward axis: rotate the antenna while level and try each of X/Y/Z until the Azimuth readout tracks correctly. Then tilt to a nonzero elevation and rotate again to confirm it is still accurate.
2. Pick the elevation axis pair: choose whichever of XY/XZ/YZ changes as you tilt the sensor.
3. Run the magnetometer calibration wizard: click Start, sweep the sensor through a full 360 degrees for 30 to 60 seconds, then click Finish.
4. Set magnetic declination for your location, then trim the azimuth and elevation offsets.
5. Raise Smoothing if the readout is jittery. Keep it at 0% while tuning axes and offsets so the display reacts immediately.

If azimuth is accurate at one heading but drifts at others, that is magnetic distortion near the sensor. Use the wizard, not the offset field, which shifts every heading by the same amount.

rotctld

TCP server on port 4533, accepting short and long command forms.

Command	Long form
P Az El	\set_pos
p	\get_pos
M Dir Speed	\move
S	\stop
K	\park
R 1	\reset
_	\get_info
1	\dump_caps
dump_state

Direction values for M: 2 up, 4 down, 8 left, 16 right. Locator commands are recognised but return unsupported.

printf 'p\n'         | nc 192.168.1.50 4533
printf 'P 180 30\n'  | nc 192.168.1.50 4533
printf 'M 16 60\n'   | nc 192.168.1.50 4533
printf 'S\n'         | nc 192.168.1.50 4533

The extended response protocol is supported by prefixing a command with +:

printf '+\\get_pos\n' | nc 192.168.1.50 4533