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4. Hardware Guide

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rirozizo edited this page Apr 13, 2020 · 4 revisions

It's Available On YouTube!

HERE

On the Raspberry Pi

  • You're gonna need constant power to the Pi. Any power source that you can rely on will do. You'd need to power on the Pi using the USB-C port on it. I have my main Internet router plugged into a UPS, so I have that on 24/7. The router has a USB Port and so I used that to power up the Pi. It works just fine.
  • To use the pins on the Pi, I used a set of female to male jumper wires (This isn't the exact one I bought since I never buy from amazon myself). These wires will usually go from the Pi itself to the breadboard so that everything is a bit more tidy.
  • The GPIO Pin used to control the relay in the script is GPIO Number (TBD) which is the (TBD) one in the physical board itself.
  • The Raspberry Pi will be used to power up the relay. For that we're going to use both the 5V GPIO pin, and the 3V3 one.

Breadboard

This section will contain everything you need to know to wire everything up from the Raspberry Pi to the relay

Relay

In my case, I bought this specific relay from this specific store in my country. Now this relay is a 4 Channel opto-isolated relay. This basically means that it can control 4 different devices at the same time. In this project, we're controlling 1 device only so far. I just figured I'd buy a 4 channel one so we can control more devices later on.

The Problem

The relay that I've bought is an "Active LOW" relay. This means that whenever you give it a LOW signal, the relay switches on. And whenever you give it a HIGH signal, it switches back off. The only problem with that is that while the Pi is booting up, before it gets to run the script itself, the relay switches on. The workaround for this is to find the right IC (Maybe an NPN Transistor) to put before the GPIO pin reaches the Relay pin so that this doesn't happen. The solution, on the other hand, is to find an "Active HIGH" relay instead. But oh well.

How to wire everything up

Please do keep in mind that working with high voltage electricity can cause serious injuries. Be careful while wiring! Please follow the guide HERE on youtube so that you don't make any mistakes.

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