2026 CS Artefact
The artefact I created for the 2026 project uses micro:bit. It is an automatic watering device designed to measure the level of moisture in the soil of a plant. In accordance to the "What if" scenario, if the moisture content is too dry, a signal is sent to automatically pump water into the plant. With this in mind, this demonstrates how embedded systems can help to monitor environmental conditions.
To meet requirements, this device uses both analog/digital inputs and outputs, the Kitronik pronged moisture sensor is used as an analog input and it measures the level of moisture in the soil. Then, it sends an analog signal to the micro:bit through the pin P0. This allows the device to repeatedly monitor the soil and its water content, this data is used to decide whether the plant needs water or not.
On the other hand, the digital output for this device is a water pump which is connected to P1 in the microbit. When the level of moisture drops below a certain value (Under 300) the micro:bit activates the pump for a short period, moistening the soil and turning off.
When the microbit is turned on manually and the program begins to run, the device begins operating automatically, continuously reading a moisture value inside a forever loop. As previously mentioned if the level of moisture in the soil drops below a certain value, the pump begins to activate for five seconds. If the level of moisture is not adequate, the pump activates again. If the level of moisture is adequate it remains off, and the system continues to monitor the soil, reading the moisture value. To connect these components together safely to the pump I used a resistor to limit the amount of electrical current into the circuit. A transistor was also a major component, acting like a switch and allowing a control signal to control a larger current from a battery pack.
My artefact also contains visual feedback, this is from micro:bits LED display. A happy face icon on the LED display is shown when the device indicates that the moisture level is adequate, however a sad face icon is shown when the device indicates that moisture levels are inadequate.
To conclude, this system demonstrates how embedded devices can be utilized to simulate real life environmental conditions used in research and in agriculture, this technology is similar to irrigation systems that help real farmers maintain healthy plants and manage water consumption. However, this device demonstrates at fraction of a price of most irrigation systems, it may assist farmers particularly in poverty stricken areas that are also affected by drought to maintain healthy plants just as much as any farmer who utilizes the average irrigation system.
A video demonstration of the full artefact is displayed below. It covers all requirements, showing how it monitors soil moisture levels and automatically activating the pump if the soil becomes too dry.
