Getting Started with Arduino

Try Other Analogue Sensors

Using the same circuit that you have seen in the previous section, you can connect a lot of other resistive sensors that work in more or less the same way. For example, you could connect a thermistor, which is a simple device whose resistance changes with temperature. In the circuit, I have shown you how changes in resistance become changes in voltage that can be measured by Arduino.

If you do work with a thermistor, be aware that there isn't a direct connection between the value you read and the actual temperature measured. If you need an exact reading, you should read the numbers that come out of the analogue pin while measuring with a real thermometer. You could put these numbers side by side in a table and work out a way to calibrate the analogue results to real-world temperatures.

Until now, we have just used an LED as an output device, but how do we read the actual values that Arduino is reading from the sensor? We can't make the board blink the values in Morse code (well, we could, but there is an easier way for humans to read the values). For this, we can have Arduino talk to a computer over a serial port, which is described in the next section.