My Smart Sprinkler System Part 1.

Introduction
You might be aware that I have been frustrated about forgetting to switch off appliances before leaving home. I guess its a sign of old age, my forgetfulness is becoming fairly pronounced. but instead of grumbling, as a technological determinist, I decided to create a smart home.

I have been tinkering with microcontrollers for some years, but creating a smart home got me jumping into the deep end of Internet of Things IOT. I have short listed several projects that I will need to create to have a smart home, and you can find them from looking through my blog for IOT and my smart home. here -

As you can see I have a whole lot of projects to keep me busy for a long long time. but not to worry, they are all simple modular systems that latch unto each other to create a smart system. I usual, I will share them here with you. you can follow the steps and recreate them for yourself if you have the basic skills of soldiering and following simple instructions. I will also share Gerber files, circuit diagrams and a whole lot of information to help you build these systems on your own.

To Sprinkle Or not to Sprinkle
for today, I will focus on the plants in my compound. I want to be able to automatically water the lawn, plants around the compound at preset times every single day of the year without much manual intervention. Yes one can easily buy a working water sprinkler of the shelve in any hardware store. but there is no fun in that. Plus, we can build a smarter system that takes cognizant of the weather to decided if it should give the plants their usual dose of water, or not water at all if it has rained in the last 24 hours.



The making of the Project Circuit Boards PCB
Examples abound on the internet on how to create a PCB.

1. Transfer a circuit trace from a Laser Printer to a paper and unto a PCB board.
2. Rule traces manually by hand.

feel free to look them up and choose which one to use. but there are basically only two methods open to you, One, to carefully draw it with your hand using a permanent maker like a fine point sharpie, or two, to use a purpose built application to design the circuit and print it out using a Laser printer (not a bubble jet ink based printer).

1. Manual Trace
I typically use the manual tracing method only when the design is simple or I don't have access to a Laser Printer and time is of the essence. Though this would typically give a rough amateurish outcome, but as usual, I put a little method to the madness. As expected, this manual process, though fast, creates a not so professional outcome. but there are a whole lot of lessons to learn from this method, so I will show you how to make a PCB using the manual writing method.

1st step is to clean the PCB with steel wool and use 4 pins to sandwich the dotted project board, the two sided board against a piece of paper.

I usually pull out a dotted project PCB as a guide to help me mark the necessary points from studying my circuit on the bread board, I experiment with where each component will fit by placing them on the paper, punching a tiny hole through the doted project board.

 At the end I get a fair idea of where things would end up and I rule the lines on the paper.

I then manually rule the necessary traces with a sharpie (permanent marker). If I make mistakes, I wipe them off with cotton wool dipped in acetone and touchup with a fine tipped sharpie or any permanent marker after it dries.

These markings are actually thin plastic traces protecting the copper upon which they are written. the protection prevents corrosion by the chemicals when dropped in an etching bathe. Spend all the time you need reviewing the traces, make sure there are not shorts and that each pad connects to a matching hole that way when drilled the components will easily fall in place. this is particularly important if they are surface mounted components - I avoid  them cos they are very difficult to solder, but they are cheaper and also small, ideal for compact designs.

If you are able to follw these steps you will have something similar to the image above and ready for the next phase - etching the copper plate in an acid bathe. I will show you just how in another article. until then cheers.