Web Radio Control generic antenna rotator controller firmware

The Web Radio Control generic antenna rotator controller firmware provides a general-purpose, text-based network protocol for controlling an azimuth antenna rotator. The firmware is built on Raspberry Pico W hardware, so that it can use the Wi-Fi network for interfacing with computer remote control.

The rotator position is determined using an absolute magnetic shaft encoder, which is a very accurate and durable sensor.

Hardware requirements

• Board: Raspberry Pico W

Suppoerted sensor for rotator position

• Rotator position input: PWM duty cycle read using Raspberry Pico Programmable I/O (PIO) and channel 0
  • Sensor: US Digital MA3 - Miniature Absolute Magnetic Shaft Encoder
    • NOTE: MA3 output needs 5V <-> 3.3V voltage level conversion for Raspberry Pico

Rotator control

Connect all pins via opto-isolators and relays to protect the Raspberry Pico.

Any Pico GPIO pin can be used for any purpose, the defaults are:

• Rotator position input: GPIO input, pin 2
• CW/CCW direction control: GPIO outputs, pins 5 and 6
• Azimuth < 0 or > 360 signals: GPIO inputs, pins 9 and 10
• Minimum/maximum azimuth signals: GPIO inputs, pins 11 and 12
• Speed control (optional): pin 7 (HIGH for fast speed, LOW for slow speed)
  • While the protocol supports speeds from 0 to 100, currently speeds 0-50 map to a slower speed and 50-100 to a faster speed.

Configuration

Define the following configuration values in file src/config.h:

Set the Wi-Fi network name and password using macros WIFI_SSID and WIFI_PASSWORD.

Set the desired TCP port for the network server using macros SERVER_TCP_PORT (defaults to 1234).

If you need to use a fixed IP address, set desired IP address using macro SERVER_FIXED_IP_ADDRESS. If the setting is commented out, the IP address will be assigned automatically using DHCP.

Set the default speed using DEFAULT_SPEED (0-100).

Set azimuth offset using ROTATOR_AZIMUTH_OFFSET_DEGREES if needed.

Build

platformio run

Flash

platformio run --target upload

Flash and monitor serial port

platformio run --target upload --target monitor

Network protocol commands

All successful responses being with OK and errors with ERROR.

Get controller state

STATE - Get controller state Example response: OK STATE AZ=50.9 SPEED=50 FLAGS=

Where:

• AZ = azimuth in degrees (0-360)
• SPEED = current speed (0-100)
• FLAGS = comma-separated list of flags:
  • CW = clockwise direction rotation active
  • CCW = counter-clockwise direction rotation active
  • T1 = threshold 1 reached (azimuth < 0)
  • T2 = threshold 2 reached (azimuth > 360)
  • L1 = limit 1 reached (minimum azimuth)
  • L2 = limit 2 reached (maximum azimuth)

Set azimuth

AZ [degrees] - Set target azimuth to [degrees]

Response: OK

Example command: AZ 180

Get azimuth

AZ? - Get current azimuth in degrees

Response: OK AZ 50.9

Move CW/CCW

MOVE CW - Start rotation in clockwise direction

Response: OK

MOVE CCW - Start rotation in counter-clockwise direction

Response: OK

Stop

STOP - Stop rotation

Response: OK

Park

PARK - Move to park position (azimuth 0)

Response: OK

Reset

RESET - Reset controller state: stop + set speed to default

Response: OK

Set speed

SPEED [0-100] - Set speed to [0-100]

Response: OK

Example command: SPEED 50

Get speed

SPEED? - Get current speed

Response: OK SPEED 50

Monitor state

MONITOR [0|1] - Monitor state changes: 0 = disable, 1 = enable

Response: OK MONITOR [0|1]

When enabled, controller outputs rotator state to the serial port continuously:

Example output: STATE AZ=50.9 SPEED=50 FLAGS=T1

Set azimuth offset

AZOFFSET [degrees] - Set azimuth offset to [degrees], can be negative or positive

Response: OK

Example command: AZOFFSET -10

Get azimuth offset

AZOFFSET? - Get current azimuth offset in degrees

Response: OK AZOFFSET -10

Get azimuth limits

AZLIMITS? - Get current azimuth limits in degrees

Response: OK AZLIMITS MIN=-90 MAX=450