The MonkMakes Plant Monitor can be connected with alligator clip leads (great for the Circuit Playground Express or micro:bit) or header pins, which are easier for boards designed to be breadboard friendly like our Feather range of boards or the Raspberry Pi Pico.

On the front side of the board, the rings have the following functions (from left to right).

• ANALOG output: This can be connected to the analog input of a microcontroller and outputs a voltage of between 0 (bone dry) and 2.5V (very wet). If you don't care about using the Plant Monitor's temperature or relative humidity (of the air) features, then this can be a simple way to interface to the board
• TX_OUT: UART serial output from the Plant Monitor. If you are using this to communicate with your microcontroller board, then this should be connected to the RX (receive) pin of the microcontroller
• RX_IN: UART serial input. This should be connected to the TX (transmit) pin of the microcontroller
• 3V: Connect to a 3.3V microcontroller power supply. 
• GND: Ground connection

The header pin connections on the back of the Plant Monitor mirror the connections provided by the alligator clip ring connectors. You can use female to male header leads to connect these to a solderless breadboard.