Forrest O. Interactive

Week 09. Input Devices

Adafruit LSM303AGR

The board that I produced last week wasn't up to the task, so I fell back to bread board.

RP2040 on breadboard with I2C

Connecting LSM303AGR to XIAO RP2040 with JST to pin connector.

Note the QUIIC connector color convention for the wires.

  • Yellow: SDL
  • Blue: SDA
  • Red: 3.3V
  • Black: ground

QUIIC pinout graphic. XIAO RP2040 pinout graphic.

Saleae probing between I2C connection between magnetometer and microcontroller.

Probing the I2C connection with the Saleae. I followed the color convention for blue and yellow wires.

Using the magsensor.ino example code, which reads the magnetometer sensor every 100ms. It is loaded on the XIAO RP2040.

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2s view. You can see the 10 times per second that data is communicated.

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1ms view. Zooming into 1 report of the sensor reading.

X: -55.35  Y: -30.60  Z: -30.75  uT
X: -54.60  Y: -30.60  Z: -30.75  uT
X: -55.50  Y: -30.15  Z: -31.20  uT

This program outputs messages like this in the Arduino serial monitor.

Next steps

  • Characterize power requirements and SPI control of addressable LED strip.
    • FastLED Arduino library.
    • WLED ESP32 web server for LED control.
  • Make circuit board that can support battery, RP2040, sensor, and LED power and control.
  • Connect mag sensor and do programming to make LED colors react to orientation changes.
  • Continue tactile labyrinth prototyping.

Reference