Lesson 1 – Measuring Temperature
During Lesson 1 we introduced the idea of the space launch to the Computer Club students who were very excited by the prospect and had many many questions to ask! We don’t know all the answers yet, but that’s part of the fun in finding out how we will make things work.
We all agreed that we would want to measure the temperature as the balloon went up and find out exactly how cold it is in near-space. We know that the BBC micro:bit can measure temperature easily, so in our first lesson we used the Microsoft PXT editor and in pairs we set one micro:bit to measure the temperature and send it via radio to the other micro:bit.
Micro:bit 1 (Transmit temperature)
Micro:bit 2 (Receiver)
We used our micro:bit to measure the temperature in different places around the school and also outside in the playground. Our results demonstrated that the temperature readings provided by the micro:bit were not very accurate as it is the temperature of the micro:bit processor that is displayed and not the actual temperature.
We repeated the experiment but this time with a TMP36 temperature sensor connected to the pins on our microbit and this provided much more accurate readings.
We think that we will measure temperature with both the onboard micro:bit sensor and the TMP36 for the external temperature as we are interested in both measurements.
Teacher’s Note: There are a number of examples of using the TMP36 sensor with the BBC micro:bit on the internet, but in preparing for this lesson it became clear that using the block editor or PXT editor introduced inaccuracies as they don’t (yet!) support floating point arithmetic. There are other tutorials for using the sensor in MicroPython which provide more accurate results. As we hadn’t introduced our pupils to MicroPython at this stage we didn’t write the program for the TMP36 in the lesson but had them pre-configured for the pupils to send the data to the receiver micro:bits from the first part of the experiment.