Electronics 4:31 pm
Ok, first post of the year. That’s pretty bad, nevermind. Just posting my latest endevours.
Here’s a pic demonstrating it working. A 300w power supply being used to light an LED 
It really isn’t that difficult. I followed the guide to make it here:
http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply
Electronics and Programming assembly, lunchbot, microcontroller, robot 11:54 am
I made my first microcontroller based robot over the weekend. It is far from finished. But it can drive around randomly. Getting something to move randomly was harder than it should have been. I realised overnight that I don’t actually need a random number generator if I want it to appear to move randomly. I just need to use any function that is chaotic.
The motors are controlled using two h-bridges. I’ve used BD139 and BD140 transistors. They can handle a continuous current of 1.5A. That will be enough for the toy motors I am using.
A PIC16F505 Microchip microcontroller is the brains behind my robot. It’s a pretty limited chip. It has room for 1024 12-bit instructions and 72 bytes of RAM. I’ll replace it once I need some extra functionality. I started writing the code in C but I had lots of problems with it. Certain math functions seem to freeze up and I kept getting confusing errors. So I’m re-writing it in assembly using gputils.
As you can see, there isn’t much to it. Eight transistors to control two motors with a few diodes and resistors and the microcontroller. The container has lots of room to add a big PCB later. In the top right corner you can see a capacitor with the battery leads connected to it. That’s the power switch. When I want to turn it on I plug that into the breadboard. It’s a bit crude, I’ll probably plug it in the wrong way or in the wrong place and fry everything knowing my luck.
I have a few plans for this little robot in the future. I want to give it more brains than any lunch box should ever have. It’ll be able to create maps and mark locations of interest. I’ll attempt to make it appear curious so when it finds something it hasn’t seen before it will keep going back until it isn’t new anymore. Hopefully I’ll make more than one and have them communicate via beeps or flashy lights. Then they can follow each other around and have twice as much fun.
I also want it to be able to recharge itself by homing in on a charging station that sends out a beacon.
I only had a 8-bit “random” number generator when I videoed this. So It repeats itself twice in that short time.
Electronics and Uni line follower, lunchbot, massey, robolympics, robot 7:13 pm
Today was the competition day for the robots we built in our first year engineering class. I’m not sure the event deserves to be called robolympics but nevermind. It was fun. We didn’t win 
Our robot was too slow and the gearbox fell apart during one of the six events. It was also the event that ours was going to do well in. Line following a spiral in and out. We made it half way. Only one team completed it properly. It’s a pity.
These robots are really really dumb. All the can do is crudely follow a line and back up and turn when they run into an obstacle.
I think our robot was the best looking. It has personality 
Electronics 9:35 pm
I lost the cycle computer for my bike a few months ago and haven’t the money to replace it. I used it as a pocket watch and that’s why I lost it. I’ve had a few ideas for projects lately and I think I can incorporate them into a neat bloggable project. A new cycle computer. Features:
I’ll probably be building it in this order. So by the end of the week I should have some photos and oscilloscope screen captures showing something that resembles a pulse.
