Cool Engineering

Info on some cool engineering projects

Wednesday, June 11, 2008

Line following robot Rev2

The battery powered line following robot is all built up and running around the floor!

Friday, June 06, 2008

Walk the line - Version 2

The picture below shows the PCB for Rev2 for the line following robot. It has a few upgrades and modifications on Rev1, namely:
- Operates off 6V supply (4AA batteries) - Rev1 was designed to operate off 4.5V (3 batteries) but this wasn't enough voltage for the motors - hence the upgrade
- The footprint on the pots fixed - just messed up the numbering of the pins - grr
- Removed some testing LED's - the algorithm has been verified now so I can free up some boardspace

Interestingly I'm still looking for a better way of protecting PCB's - the following have been tried:
- No protection: copper corrodes and looks horrible
- Leaving photo resist layer on - it eventually scratches off in patches, that corrodes and looks horrible
- Solder screening - invariably some bridges are created which need to be tracked down, doesn't look particularly nice
- Spray on coating (currently use) - dries overnight, smells horrible, makes a bit of a mess when soldering - but does the job fairly well (although it can be a bit patchy) - possibly I have to try some different spray on coatings

Thursday, June 05, 2008

POV Plans

After quickly coding up some C code to drive LEDs I was quickly able to write some POV based messages when the LED line was waved through the air. Unfortunately I didn't have a chance to take any photos of the writing that was being flashed through the air. The grand plan for open day is to use a wireless MSP430 module to allow us to wirelessly program whatever message we would like.

Below I have included a couple of photos that were taken from the version 1 line tracking robot. For interests sake the CD that I used for the baseplate was from the TI microprocessors that didn't quite work - the device ID for the USB driver was wrong (and the version of IAR studio was 2 versions old).

Wednesday, June 04, 2008

Walk the line

Yesterday I finally assembled the line-following robot (the latest of my robotic creations) into a form that I could code up and test. An hour or two later the PID algorithms were more or less working (currently only the 'P' is tuned in) and my line following robot is following lines.
In the video you will see some power cables and such detracting features as the photo-sensors being held on with electrical tape. Thesether than simply running around on my desk following the oval like (or an alternate circuit looks sowill be remedied in version 2 - which will be powered by 4 AA batteries and will have a proper sensor mounting system. This will give it greater range of mobility so we can plot a path to follow around the lab rather than on my desk around the oval like (or alternately an track looking something like Australia if you squint) printed track.