In this hands-on workshop, we will construct a device to measure soil moisture from just a pair of nails and BBC micro:bit. Once calibrated against different soils samples we will then connect a water pump to make an automated plant-watering system. All apparatus, instructions and code provided.
The BBC micro:bit has a few on-board sensors which we can access to create a simple sensor, with an output on the LED display. Taking this a little further there is a simple data-logging app for iOS and Android that connects via Bluetooth and will collect and graph real-time data from the accerometers, magnetometer or temperature sensor of the BBC micro:bit. I will provide a quick demonstration of these features before moving on to the main activity.
Taking things a step further still, it is possible to construct your own sensors for experients in the school lab. All secondary schools were sent a set of BBC microbits so hopfully most schools will have access to these. If not, then they are relatively inexpensive to purchase. In this workshop we will learn how to connect a pair of nails to inputs on the BBC mirco:bit using standard lab equipment and write some simple code to create a device to test the moisture level of soil in a plant pot. After calibrating our sensor against some different soil samples we will then add a small water pump to the output of the BBC micro:bit to create an automated plant-watering system.
We will be using a kit that has been kindly loaned to us for this session by Science Scope. Detials of which you can find here
here
