This lab activity allows students to get familiar with Arduino's, a very 'Real-world' product that can be used in an almost limitless set of practical applications...if you know how to work them.

Students count Binary Coded Decimal (BCD) using four LEDs. Consider a pattern of 4 bits: the smallest bit takes a value of 1, the next 2, then 4, and the largest 8. By adding the sum of the 4 bits that are “HIGH” (1 or “on”) in a weighted sum, we can represent larger numbers. In fact, the total number of different states that we can represent is 24 (the power 4 is used because we have 4 bits). More details in the lab sheet...

In this lab students are required to construct a temperature monitoring circuit to measure the temperature, using an Arduino. The circuit will need to light up LEDs based on the temperature; a typical application could be to detect if someone has a high temperature, to alert them to a potential health issue.

Task Specification

The circuit must have a temperature sensor and a button for input, and two LEDs for outputs. It must perform the following functions:

• If no button is pressed, do nothing - both LEDs remain off

• If the button is held down, light up LEDs in the following pattern:

  • Temperature below 20°C - one LED

  • Temperature above 20.0°C - two LEDs

(yes, this is not a realistic body temperature - but this should be easy to demonstrate using household equipment, and could be easily adapted!)