Getting Started
This is a perfect application for a $14 Raspberry Pi Zero WH as this device is compact, inexpensive, powerful, and has built-in WiFi. Here is the list of everything we need per sensor node and the approximate cost:
- Raspberry Pi Zero WH ($14)
- Micro SD card ($4)
- Raspberry Pi power supply ($8)
- DHT22 Temperature/Humidity Sensor ($5)
- (Optional) Raspberry Pi Zero W case ($6)
The setup for each sensor node is going to cost ~$31 plus shipping, taxes, and the case. You can easily get each item above in bulk to minimize shipping costs with the exception of the Raspberry Pi Zero WH, which may be more challenging outside of the UK. You cannot find a vendor that allows you to purchase more than one Zero per Raspberry Pi Foundation rules.
We are using the $14 Zero WH instead of the $10 Zero W since the Zero WH has the header pre-soldered, which will make our project assembly super quick and easy.
We are using the DHT22 temperature/humidity sensor because of its temperature accuracy (+/- 0.5 °C), humidity range (0–100%), and low cost. We also want something really easy to wire up without having to add a pull-up resistor.