picohost

Host control and management tools for Raspberry Pi Pico devices running the EIGSEP multi-application firmware.

Overview

This package provides a Python library for communicating with Raspberry Pi Pico devices running the custom multi-application firmware. It includes:

• Base communication classes for serial JSON protocol
• Specialized device classes for motor, temperature control, and RF switch applications
• Test scripts for development and debugging
• Device discovery and flashing tools
• Example code showing usage patterns

Features

• Automatic device discovery - Find connected Pico devices
• JSON command protocol - Send structured commands and receive responses
• Background monitoring - Continuous status updates in separate thread
• Context manager support - Easy connection management
• Extensible design - Easy to add support for new applications

Installation

# Install in development mode
pip install -e .

# Or install with dev dependencies
pip install -e ".[dev]"

Quick Start

Basic Usage

from picohost import PicoDevice

# Find available devices
ports = PicoDevice.find_pico_ports()
print(f"Found devices: {ports}")

# Connect and send commands
with PicoDevice(ports[0]) as device:
    device.send_command({"cmd": "status"})
    response = device.wait_for_response()
    print(f"Response: {response}")

Motor Control

from picohost import PicoMotor

# Connect to motor device (DIP switch set to 000)
with PicoMotor("/dev/ttyACM0") as motor:
    # Move 1000 steps on both axes
    motor.move(pulses_az=1000, pulses_el=1000)
    
    # Set individual axis positions
    motor.set_azimuth_position(5000)
    motor.set_elevation_position(2000)

Temperature Control

from picohost import PicoPeltier

# Connect to temperature controller (DIP switch set to 001)
with PicoPeltier("/dev/ttyACM0") as peltier:
    # Set temperature to 25C on channel 1
    peltier.set_temperature(25.0, channel=1)
    peltier.enable(channel=1)
    
    # Get current temperature readings
    status = peltier.get_status()
    print(f"Current temp: {status.get('temperature', 'N/A')}°C")

RF Switch Control

from picohost import PicoRFSwitch

# Connect to RF switch device (DIP switch set to 101)
with PicoRFSwitch("/dev/ttyACM0") as switch:
    # Set switch state to 5
    switch.set_switch_state(5)
    
    # Get current switch state
    state = switch.get_switch_state()
    print(f"Current switch state: {state}")

Device Classes

PicoDevice (Base Class)

The base class provides core functionality:

• Connection management - Connect/disconnect to serial ports
• Command sending - Send JSON commands with error handling
• Response parsing - Parse JSON responses from devices
• Background monitoring - Continuous reading of status updates
• Custom handlers - Set callbacks for responses

Specialized Classes

Currently implemented:

• PicoMotor - Stepper motor control (APP_MOTOR = 0)
• PicoPeltier - Temperature control (APP_TEMPCTRL = 1)
• PicoRFSwitch - RF switch control (APP_RFSWITCH = 5)

Firmware-only applications (no Python class yet):

• Temperature Monitor (APP_TEMPMON = 2) - Temperature sensing only
• IMU Sensor (APP_IMU_EL = 3, APP_IMU_AZ = 6) - BNO08x sensor interface
• Lidar Sensor (APP_LIDAR = 4) - Lidar sensor interface

Command Protocol

All communication uses JSON over serial (115200 baud). Commands are sent as JSON objects followed by newline:

{"cmd": "command_name", "param1": value1, "param2": value2}

Responses are JSON objects:

{"status": "ok", "result": "success"}

Test Scripts

The package includes several test scripts in scripts/:

• test_motor_pico_v2.py - Motor control testing
• test_peltier_v2.py - Temperature control testing
• test_rfswitch_pico_v2.py - RF switch testing
• monitor_picos.py - General device monitoring
• example_usage.py - Usage examples

Run tests with:

# Motor test (requires DIP switch set to 000)
python scripts/test_motor_pico_v2.py /dev/ttyACM0

# Temperature test (requires DIP switch set to 001)
python scripts/test_peltier_v2.py -p /dev/ttyACM0

# RF switch test (requires DIP switch set to 101)
python scripts/test_rfswitch_pico_v2.py /dev/ttyACM0

# Monitor all connected devices
python scripts/monitor_picos.py

Development

Running Tests

# Run unit tests
pytest

# Run with coverage
pytest --cov=picohost

Adding New Device Types

1. Create a new class inheriting from PicoDevice:

class MyDevice(PicoDevice):
    def my_command(self, param):
        return self.send_command({"cmd": "my_cmd", "param": param})
        
    def get_status(self):
        """Get device status"""
        return self.send_command({"cmd": "status"})

2. Add to __init__.py:

from .mydevice import MyDevice
__all__.append("MyDevice")

3. Create test script following the existing patterns in scripts/.

4. Update this README with usage examples.

Architecture

The firmware implements a multi-app dispatch system where DIP switches (GPIO 2,3,4) select which application runs:

• APP_MOTOR (0) - Stepper motor control
• APP_TEMPCTRL (1) - Temperature control with Peltier elements
• APP_TEMPMON (2) - Temperature monitoring only
• APP_IMU_EL (3) - IMU sensor (elevation / board)
• APP_LIDAR (4) - Lidar sensor interface
• APP_RFSWITCH (5) - RF switch control
• APP_IMU_AZ (6) - IMU sensor (azimuth / antenna)

Each app implements:

• app_init() - Initialize hardware
• app_server() - Process JSON commands
• app_op() - Continuous operations
• app_status() - Send status updates

DIP Switch Configuration

Set GPIO pins 2, 3, 4 to select the application before powering on:

Hardware Support

• Raspberry Pi Pico 2 (RP2350) - Primary target
• Raspberry Pi Pico (RP2040) - Also supported
• USB Serial - CDC ACM interface (VID:0x2E8A, PID:0x0009)
• Device naming - Enumerates as PICO_000, PICO_001, etc.

Flashing Tool

The package includes a flashing tool for managing multiple devices:

# Flash all connected Picos
python -m picohost.flash_picos --uf2 ../build/pico_multi.uf2

# List available devices
python -m picohost.flash_picos --list

Contributing

1. Fork the repository
2. Create a feature branch
3. Add tests for new functionality
4. Run tests and ensure they pass
5. Submit a pull request

Priority areas for contribution:

• Python classes for APP_TEMPMON, APP_IMU_EL, APP_IMU_AZ, and APP_LIDAR
• Additional test scripts
• Enhanced device discovery and management

License

MIT License - see LICENSE file for details.