This type of sensor uses two metal electrodes placed in the soil. The electrical resistance between them varies depending on the amount of water: the higher the moisture, the lower the resistance, as water allows for better electrical conduction. When the soil is dry, the resistance is much higher. The microcontroller evaluates these changes to assess how wet or dry the soil is.
The circuit uses an ATtiny45 microcontroller, with an LED that lights up via PB0 and a moisture sensor that sends data to PB4. It also includes programming pins and power connections.
Now that we have the circuit ready, we will proceed to cut our PCB using the appropriate tool. You can download the circuit file from the following link:circuito para cortar nuestra PCB
The next step will be cutting the board using the Roland Monofab. Once cut, I will proceed to solder the components in their proper places on the circuit. This was the final result of the process, with the board assembled and ready for testing or adjustments.
For this task, I used the PCB I made duringWeek 4: Electronics Production. The function of my PCB will be to supply the necessary voltage to the input board and load the code that will read sensor data and turn on a LED.
With the code completed, I will proceed to make the connections on my Week 4 PCB to supply the necessary voltage. By connecting the corresponding pins, they will act as bridges, ensuring the system works properly.
Once everything is finished, I will test my input circuit to analyze its operation in detail and observe how the data changes in response to humidity.
video funcionando
As final reflections, this project allowed me to better understand the integration between hardware and software, from creating the PCB to programming it to read sensor data and activate the LED. It was an opportunity to deepen my knowledge of handling analog inputs and the importance of precise design to ensure proper circuit operation. Testing helped me visualize how environmental conditions affect the readings, reinforcing the usefulness of such systems in monitoring applications.