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INPUT DEVICES

This week, I will work on probing the analog levels and digital signals of an input device. During the process, I will use a multimeter and an oscilloscope to measure and analyze the different signals that the device will generate.
First, I will focus on the analog signals. I will observe how changes in the input affect the output of the device and identify patterns in the waves that I measure. This will help me understand better how continuous signals behave and their importance in data processing.
Next, I will move on to the digital signals. Here, I will notice that the variations will be more discrete and easier to interpret. I will learn to differentiate between high and low levels and how these translate into useful information for the system.
Reflecting on this experience, I will realize how fundamental it is to understand both analog and digital signals for the design and improvement of electronic devices. Each type of signal will have its own relevance and applicability, and this exercise will provide me with a clearer view of how they interact in a system. I am excited to apply this knowledge in future projects.

My input

plain table
For this task, I have decided to use a humidity sensor instead of a temperature sensor to measure the plant's moisture levels. My goal is for the LED to turn on automatically when the plant is dry. I will use an appropriate soil moisture sensor to detect the moisture levels, and a microcontroller such as the ATtiny to process this information and activate the LED when needed.

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.

Design to my input circuit

Squematic diagram

plain table

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.