Input Device

A. What are Input Devices?

Input Devices are those components which allow person to enter data, command, signals into a computer or microcontroller. This helps to interact with the outside world by receiving information from users, sensos, or other systems.

B. Trying Flex Sensor

I finally got to try out a flex sensor for the first time!

The plan was simple—if the sensor bends past a certain point, an LED should blink.

Making sure all the connections were easy. The sensor was hooked up to an analog pin, a 10KΩ resistor to GND, and an LED to a digital pin.

But. this dd not work out. I tried changing codes thrice, but led wasn't blinking.

It was important to ensure that the processor which was in use, in arduiono IDE was installed in Library.

Since, code was not not working, planned to check indiviaually whether led, jumper connections, sensor were at right place. Went ahead by checking Sensor Monitor.

Readings were between 2-3-4, but it should have been somewhere from 500-600. Here, error was found. Something was wrong with my sensor connection input.

C. Using Tilt Sensor

So, I decided to mess around with a tilt sensor and my RP2040 to see if I could make something fun happen. The plan? If the sensor tilts, an LED should turn ON.

What is a Tilt Sensor?

A tilt sensor is like a tiny switch that reacts to movement. Inside, there's either a metal ball or liquid mercury that moves when the sensor is tilted. This either closes or breaks the circuit, giving an output of HIGH (1) or LOW (0).

Imagine a rolling marble in a box—if the box is flat, the marble stays still. If you tilt it, the marble rolls to a different side. That’s pretty much how this sensor works!

Since I wanted a simple ON/OFF reaction, I set up the tilt sensor with one pin connected to GP15 and the other to GND. The LED was connected to GP14 through a 330Ω resistor, and I also added a 10KΩ pull-down resistor to ensure stable readings and avoid unwanted flickering. The idea was straightforward—when the sensor is upright, the circuit remains open, and the LED stays OFF. But when the sensor tilts, it closes the circuit, sending a HIGH signal to the RP2040, which turns the LED ON.

At first, things didn’t go exactly as planned. The LED kept flickering randomly, even when I wasn’t moving the sensor.

I took an average of multiple readings to smooth out any noise. Once these adjustments were in place, the system worked exactly