ItsyBitsy M4 Express Projects 24 & 25:

9 DoF IMU or Accelerometer


(click to enlarge)


 9 DoF IMU v1.0 Schematic


 9 DoF IMU v1.0 PCB Layout


 9 DoF IMU v1.0 PCB (Top)


 9 DoF IMU v1.0 PCB (Bottom)


 9 DoF IMU v1.0 Bill of Materials



Accelerometer v1.1 Schematic


Accelerometer v1.1 Board Layout


 Accelerometer v1.1 PCB (Top)


 Accelerometer v1.1 PCB (Bottom)


Accelerometer v1.1 Bill of Materials



Projects 24 & 25 continue on from Project 23 using these devices:

 - Adafruit ItsyBitsy M4 Express #3800 (a.k.a. IB-M4E) (more I/O pins than QT PY)

 - Adafruit #4311 2.0" TFT display

 - Adafruit #2652 BME280 T/H/BP sensor

 - Adafruit #2124 LiPoly charger

 - Joystick JS5208 and Adafruit #4697 rubber nub cap

 - Adafruit #4667 PIR BL412


For each project a sensor board was added as shown below:

Project 24: Adafruit #4754 9 Degrees of Freedom Orientation IMU

Project 25: Adafruit #2809 LIS3DH Accelerometer


Testing Your Accelerometer or 9DoF:

Make sure you install the appropriate libraries before testing the code below. You'll need to click on these #4754 and #2809 links for instructions.

When you initially receive your your Accelerometer, test it with acceldemo_IBM4E.ino

Test your 9 DoF with 9DoF-IMU_rotation_vector.ino first before adding it to the PCB.


Setting Up Your System:

 - Download and follow this .pdf file to setup the ItsyBitsy M4 Express microcontroller for Arduino: https://cdn-learn.adafruit.com/downloads/pdf/introducing-adafruit-itsybitsy-m4.pdf. Follow the directions regarding the .uf2 file because it is needed for either Arduino or CircuitPython programming. Search Adafruit.com for info on "flash_nuke.uf2" to cleanup your board if double-pressing the Reset button won't fix it. Check here first: https://learn.adafruit.com/getting-started-with-raspberry-pi-pico-circuitpython/circuitpython

 - Download and follow this .pdf file to setup the 2.0" 320x240 TFT display for Arduino: https://cdn-learn.adafruit.com/downloads/pdf/2-0-inch-320-x-240-color-ips-tft-display.pdf

 - Download and follow this .pdf file to setup the BME280 or BMP280 sensors: https://cdn-learn.adafruit.com/downloads/pdf/adafruit-bme280-humidity-barometric-pressure-temperature-sensor-breakout.pdf. Adafruit's new driver requirements seem to ward off the Chinese clones of their sensors, that is, what once worked no longer does. The Adafruit board is $15us so I'll continue to use their product.



Here's some code that is a work in progress as I add more of the PCB devices to the board.

The temp/BP sensor, RTC and Accelerometer are started up (which includes a quick test of each).

Text is displayed on a non-black background, a different colour for each reporting line, e.g. date & time are black text on a white background.





Updated 2023-03-09 @ 8am