Process

Overview

Over the period of 15 weeks, I've gained much exposure to many aspects of electronics, from the basics like soldering to rather advanced microprocessor programming and these helped me to not just know theories from the electronics class but also, allow me to put those knowledge into use. Practical exploration allows in depth knowledge of the principles of electronics and better knowledge gained from it allows more creative control over ones work. While not all the components work in this project, 90 percent works and I would say thats a big success for me because in the course of the process, I have been facing troubles with every single component and I have to research and learn and try to get it working mostly all by my own efforts.

Led Matrix / drivers


Phillips 74hc595 driver setup

The first part of the project that I worked with was to try and get the led matrix working but immediately I was faced with an array of problems. I chose to use separate led bulbs as it is brighter and there is more that can be done with it but the downside is, there are alot more to be done. The first led driver that i bought was the phillip 74hc595 shift register led driver, while this driver handles the power output well and led movements very well, it is limited to a linear movement. To the best of my knowledge and after an enlightening explanation by Jens Wunderling , I realised that this driver was not able to control each led individually and in the way that I wanted to. Nevertheless, I tried experimenting it somemore and got pretty interesting results like how you can output multiple drivers ( daisy chaining) from the same initial driver output. Also I learnt quite abit about how bit shifting works.


Led 8x8 matrix for max 7219

Next I got a max 7219 which proved to be more suitable for my project, it is able to address each led individually with a specific setup which required alot of soldering. This however takes up quite alot of space and it would really help reduce alot of space if I could have used a custom printed circuit board instead.

Sensors / Components

I got alot of components and electrical parts for this project, some of them were not used due to practical reasons and some because it is not working at all. Here are some of the lists.

Fans / Motor

Initially I tried to use a pc cooler fan to try and get the rpm readings from the fan, unfortunately it did not work out as the brushless motor within it does not generate any electrical current by its own. Also the resistance of the fan is too hard for the wind to move. Next I tried 2 other motors which did not work as well because of the resistance of the motor that were not smooth enough. I also tried different fan blades which did not work too well.


The left and right outer motors had high resistance which did not allow the fans to move smoothly. However the center one with 4v was smooth enough to spin around long.


The two fans here could not capture enough win to move the motor.


IR interrupter

Next I tried to get readings by using an infrared interrupter, what this component does is that it detects the disruption of signal in between the 2 points so that is records the number of times it gets interrupted per minute. The downside of this method is that the programming part got too tedious. Finally, I managed to find a 4v motor from simlim towers for 2 dollars that worked perfectly.

Pir IR Sensor


Initially I had wanted to detect human presence as well so I got this nice ready made component sensor for $20 which worked perfectly for me. It is infrared so it detects movements even at night.

LDR Sensor


The ldr sensor is a light diode resistor that changes its resistance according to the light level. It is very cheap and one of the easiest to work with.

SHT11 temperature/ humidity sensor


This sensor is one of the most expensive but superbly accurate. ItŐs a digital sensor but the program for it proved to be rather complex.

Radio Transmitters / Transceivers


Maxstream Zigbees
Sparkfun Klp RF link

It has been most unfortunate that I have been unable to get any radio transceivers working , somehow I have not been able to communicate with the radios, even with the 2nd one that I got, Roshan Peiris tried to troubleshoot for me but to no avail also.

Improvements / optimisation

There are still alot that needs to be improved on and optimised for the design is not complete and spaces are wasted , more importantly, I would like to get the radio communication up and working soon. Roshan from mixed reality lab has promised that I can bring it to his lab to troubleshoot it.