Week 8: Input Devices

Assignment: Measure something - add a sensor to a microcontroller board that you have designed and read it.

I chose to use an accelorometer as my sensor (ADXL345) for this weeks project, since it’d be cool to control my final project with my hands/other motion.

First, using the pinouts, I configured the schematic on Fusion for the board. In order to read the values from the register, I used the I2C communication protocol between the ADXL and Xiao Rp2040, which requires pull-up resistors to create a high signal when no voltage is pushing a pin down.

The ADXL345 is a very tiny chip, so soldering it was very tricky. I gently lined the traces with solder paste, and used the hot air gun to melt the paste.

Don’t leave the tape on while heating up the board from the bottom!

God bless solder paste.

In the end, it worked! It’s a bit finicky in terms of detecting acceleration, but very good at detecting orientation!

Files

Note that the schematic pictures above are from combination of input/output devices week. I built on top of my accelorometer board using thes ame Fusion file, but can’t seem to revert history.
Week8+Week9 Accel + Stepper Board