"Compound interest is the eighth wonder of the world. He, who understands it, earns it; he who doesn't, pays it."
- Albert Einstein
We have come a long way since we started. We saw how to build basic prototypes with the Arduino in the previous chapters. In this chapter, we will take a step ahead by learning to build a compound device prototype using the Arduino platform.
We will cover the following topics in this chapter:
- Introduction to a compound device
- Using a smoke detecting sensor device
- Reading digital input from a sensor device
- Reading analog input from a sensor device
- Working with a MQ2 gas sensor
- Working with a Piezo Buzzer
- Sending digital signals to peripherals
- Receiving digital signals to peripherals
- Sending analog signals to peripherals
- Receiving analog signals to peripherals
- Read and writing using SD cards for local storage