MicroPython Driver for MLX90640 IR Camera

Introduction

This repository contains a MicroPython driver for the MLX90640 thermal camera sensor. This driver is a small refactored and small optimized version based on the original Adafruit CircuitPython MLX90640 driver, but for MicroPython.

(There are still things to refactor and optimize here, but the current version is enough to get you started.)

This driver was tested on:

• Raspberry Pi Pico W

Basic Usage

To use the MLX90640 driver with MicroPyServer, follow these steps:

1. Initialize and configure the I2C connection:

   import machine
   i2c = machine.I2C(1, sda=machine.Pin(6), scl=machine.Pin(7), freq=400000)

2. Set up the MLX90640 sensor with the desired refresh rate:

   from drivers.mlx90640 import MLX90640, RefreshRate
   mlx = MLX90640(i2c)
   mlx.refresh_rate = RefreshRate.REFRESH_2_HZ

3. Continuously capture:

   frame = init_float_array(768)
   while True:
       mlx.get_frame(frame)
       print(frame)

Example Integration with MicroPyServer

Here is a simple example of how the MLX90640 driver can be integrated with MicroPyServer to serve thermal imaging data over a network. It will be helpful if you don't have appropriate screen to show the image.

import machine
from micropyserver import MicroPyServer
from drivers.mlx90640 import MLX90640, RefreshRate, init_float_array

class IrCameraServer:
    def __init__(self):
        i2c = machine.I2C(1, sda=machine.Pin(6), scl=machine.Pin(7), freq=400000)
        self.mlx = MLX90640(i2c)
        self.mlx.refresh_rate = RefreshRate.REFRESH_2_HZ
        self.frame = init_float_array(768)

        self.server = MicroPyServer()
        self.server.add_route('/', self.show_index)
        self.server.add_route('/result.bytes', self.show_result)

    def show_index(self, request):
        # Serve HTML content
        
        self.server.send('HTTP/1.0 200 OK\r\n')
        self.server.send('Content-Type: text/html; charset=utf-8\r\n\r\n')

        with open('renderer.html', 'r') as file:
            self.server.send(file.read())

    def show_result(self, request):
        # Serve thermal image data
        
        self.server.send('HTTP/1.0 200 OK\r\n')
        self.server.send('Content-Type: application/octet-stream\r\n\r\n')
        self.mlx.get_frame(self.frame)
        self.server.send_bytes(bytes(self.frame))

    def run(self):
        # Need to connect to WiFi before running the server
        self.server.start()

# Usage:
camera_server = IrCameraServer()
camera_server.run()

Implementation of MicroPyServer.send_bytes:

    def send_bytes(self, data):
        """ Send data to client """
        if self._connect is None:
            raise Exception("Can't send response, no connection instance")
        self._connect.sendall(data)

NOTE: You can find file renderer.html in this repository.

Contributing

Contributions to enhance or extend the functionality of this MLX90640 driver are welcome.

License

This project is licensed under the MIT License - see the LICENSE file for details.