How we made a home cooling fan smart with JavaScript
(This article is co-authored by Chinedu Imoh)

Our friend had a damaged fan — the fan’s control board got fried. We were tired of seeing it lie around the house when we visit her on weekends but recycling electronics in Nigeria is not a thing. 

We thought, instead of harming the world by throwing the fan away, we could just pull out the damaged board, join the wires under the hood manually and still have the fan work.

With a flat screw driver, as seen in the picture on the right, we pulled out the control panel of the board and cut out the wire from the board.

At this point joining a couple of wires would get the fan back to live but it’s the era of IoT and we thought to ourselves — “this is a free fan we could play with, what can we do?”

Well it didn’t take us too long to REALIZE that with a Tessel 2 and a relay, we cloud turn this so-called damaged fan into one of the smartest device in our friend’s home.

This article outlines our journey to how we made this fan smart. At the end, you will learn:

  1. What requirements we used to make this fan smart
  1. How we used a relay to interface this fan with a Tessel IoT board
  1. How we controlled this fan with a computer (can be a phone) through a Tessel board

The best way to follow this article is to get the same devices we used but of course you might not have that luxury. This is why we are structuring this post in a way that you can apply what ever you learn in your IoT journey — regardless of whether:

  1. This is your first look at IoT or 
  1. You have been doing IoT stuff but want to learn how to control home appliances with IoT


This upcoming list does not have to be followed religiously and you can replace each part with what ever works best for you:

  1. A room fan — we are using Honeywell QuietSet Fan
  1. Tessel 2 IoT Board
  1. Basic knowledge of JavaScript/Node

  • You can buy a Tessel kit which comes with Tessel 2, cables, few sensors, etc. The relay and fan does not come with the kit but you can get those from the links.

Circuit Diagram

We are totally aware that this article targets both developers as well as electrical engineers. With this in mind, we chose to not draw a professional circuit diagram but a simpler flow diagram of what the connections look like.

The secondary reason for not making a professional circuit diagram is because we both have computer programming background and suck terribly at such.

The only thing you should care about are the wires we pulled out of the control chip. That said, feel free to skip the next section if you don’t want to understand where those wires poking out of the fan came from.