Plant Watering Calibration
Sections
1. Introduction
2. Hardware Check
3. Calibrate Water Sensor
4. Calibrate Soil Moisture Sensor
5. Upload to Arduino
1. Introduction
The plant watering kit monitors the soil moisture of a potted plant and waters it when a threshold is met. It will also monitor the water level of a reservoir and sound a buzzer if it gets too low.

If you haven't already assembled your kit, you can find assembly instructions here. After your kit is assembled, we'll need to upload the plant watering sketch to the Arduino. This lesson will lead you through calibrating the water sensors for the plant watering sketch.

2. Hardware Check
Please plug in your Arduino if you haven't already.
3. Calibrate Water Sensor
Connect the water sensor (photo on right) to pin A2 if it is not already. Put your finger between the wires. Observe the changing sensor value:
Current Sensor Value
0
Make sure the water container is empty, then press the Record Empty button.
Empty
0
Fill the container with water, then press the Record Full button.
Full
0
Then click the Compute Threshold button. We'll set the threshold to be halfway between the above measurements.
Threshold
0
4. Calibrate Soil Moisture Sensor
Connect the soil moisture sensor (photo on right) to pin A0 if it is not already. Put your finger between the wires. Observe the changing sensor value:
Current Sensor Value
0
Place the sensor into some dry soil, then press the Record Dry button.
Dry
0
Place the sensor into some wet soil, then press the Record Wet button.
Wet
0
Then click the Compute Threshold button. We'll set the threshold to be halfway between the above measurements.
Threshold
0
5. Upload to Arduino
Soil Moisture Sensor Threshold
0
Water Sensor Threshold
0
Write down the thresholds then go to the Arduino Programmer and click on the options tab to enter the thresholds. After you have entered the thresholds, select your board and port, then click Upload.

6. Lesson Done