Quantity   Component name
1 × BBC Micro:bit From your preferred retailer, should be easy enough to find, if you don't already have a board.
1 × ESP32 Devkit For this project, I used the classic AliExpress ESP32, found here: https://www.aliexpress.com/item/32928267626.html?spm=a2g0s.9042311.0.0.27424c4diSTFua
1 × SparkFun Weather:bit Found here: https://www.sparkfun.com/products/15837
1 × SparkFun Soil Moisture Sensor Found here: https://www.sparkfun.com/products/13322
1 × Buck Converter Step 12V input down to 3.3V. I used AliExpress buck converter, found here: https://www.aliexpress.com/item/32826540392.html?spm=a2g0s.9042311.0.0.27424c4dBWJoEV
1 × TIP31C Power Transistor Just standard TO220 package
1 × 47 ohm Resistor Used for TIP31C base transistor