In this project, we'll use an npm module that allows us to set up a Raspberry Pi broker on a Pi—if you have one Pi, we'll have it talk to itself as if it's two separate devices, and if you have a second Pi, we'll have them talk to each other.
If you are only using your original Pi, skip this section.
Use the instructions in Chapter 1, Setting Up Your Development Environment, to set up your second Pi. You do not need a cobbler or any other accessories for this project; if you use a second Pi, you just need a good power source and a microSD card set up as stated in Chapter 1, Setting Up Your Development Environment.
If you are using two Pis, the Pi without the cobbler is the broker Pi, and your original Pi with the cobbler is the client Pi.
If you are using two Pis, you will want to set the hostname of the broker Pi so that they don't collide. To do this, run the following command:
sudo raspi-configThen select Network...