This week we're learning about different Inputs, measuring their values with our board, and making some noise.
In the group assignment we read the values of both soil sensor and microphone sesnor plus potentiometer. I'll document the soil sensor and microphone sensor.
First me an Doaa took thesoil sensor and started and use a simple code to display the reading of the sensor on the serial plotter and watched the fluctuations. We could see the transition from ~+1000 to ~800 once she put it in the water but we saw the noise as well.
This is logical since the probe is an exposed conductor that acts like a potentiometer its resistance vary inversely with the moisture. When Doaa put it in the water, its conductivity got higher, therefore the resistance was lowered. The sensor produces an output voltage based on the resistance
The Microphones are devices that convert the sound energy into electrical energy. Their sensors help an electronic product capture sound waves. The type we use is an Electret microphone (ECM). They use electrostatic and magnetic properties to function with an electret diaphragm that acts as a single capacitor plate. Once a signal is captured due to variation in capacitance, it's amplified.
We measured the signal raw at first and THE NOISE was Maddening, so Saeed introduced us to the art of calibrating our sensors with coding. We tuned the readings until it showed only the signal.
Credits: Engineering Product Design
Collin's Lab. I already decided to fabricate the board I designed in week 6. I only needed some pretifying for the schematics.
My components are listed in week 6's page . I used the same components but I added 2 Zero ohm resistors that can act as bridges.
I used the same design but modified some things.
After I made the things a bit neater I added the 0 ohm resistors in put them is rectangle with the name "Bridges". I like to arrange by functionality in my schematics.
I used adrian's code
Capacitive Touch PCB in KiCad