Week 8

Last week! Here is the video that shows our sensor finally working to detect the difference of humidity of soil.

The code for the Arduino creates a square wave for sensor and for reference, then we use a library that calls an interrupt function when the voltage of sensor becomes equal to the reference. We measure time at beginning of each loop cycle and when the interrupts starts so we can calculate the time constant as difference of those times.

Arduino code
Arduino code

Also we print the last part of model:

3D-printed arm with water dispenser
3D-printed arm with water dispenser
3D-printed plate
3D-printed plate
3D-printed bottom reservoir
3D-printed bottom reservoir

Since the board was still a prototype we had also to etch the final version. We decided to use etching since it’s a faster method and it guaranteed a perfect result:

Final PCB
Final PCB
Final PCB
Final PCB