This was a fun chapter to get you used to solving real-world problems. Think of ways in which this system can be improved by adding other sensors like an LDR or actuators like a water pump to make this project even better.
Let's recap what we learned:
Understanding the dielectric constant of the soil, which can be thought of as the soil's ability to conduct electricity
How we can interface the soil to our circuit using probes
Then we came across our super voltage divider circuit again
Using conditional statements to give our project logic
You have got through the journey in this book with flying colors, High-5! (Use the Bot!)
I hope what you have learnt so far would have changed your perspective of how you can do things by creating objects that can think for themselves and interact with you or the world around them.
This is just the beginning of the huge playground of sensors, actuators, electronics, and mechanisms out there that control everything from the automatic breaking system in cars...