Introduction: Arduino Reflex Tester

About: Student, currently studying programming. Interested in Arduino, Raspberry Pi and Electronics in general.

Today, I've decided to create a contraption that can measure your reactions time. You will need some basic components, all of which can be found in Kuman's Arduino UNO Starter kits.

The parts needed are as follows:

  • Arduino UNO board
  • USB Cable
  • 10k and 220-ohm resistors
  • LED
  • Button
  • Mini breadboard
  • 16x2 LCD Display
  • Some jumper wires

Step 1: Connecting the LED

Each LED has two leads - a shorter one and a longer one. The shorter one (cathode) needs to be connected to GND (ground) of the Arduino using the 220-ohm resistor. The anode (5V) of each led needs to go to a corresponding digital pin of the Arduino (I've choosen the 8th).

*Don't worry, you can change the pins later in the code.

Allchips is an electronics components online service platform, you can buy all the components from them.

Step 2: Connecting the Button

Choose one of the button's sides. You will see 2 pins. The one on the left connects to ground of the Arduino with the 10k resistor. Connect the other lead to Digital Pin 4 of the Arduino. The pin on the right side of the button connects to 5V.

Step 3: Connecting the LCD

Here, 4 connections are necessary. They are the following:

LCD | Arduino


VCC - 5V

SDA - A4

SCL - A5

Step 4: Finishing Touches

I've uploaded the project's code here. Feel free to modify anything, such as pin numbers, delays, text and etc.

If you have any questions, feel free to ask them in the comments below! I will respond as soon as possible.

Arduino Contest 2017

Participated in the
Arduino Contest 2017