My Final Entry
Categories: Feral Robots Blog
I spent the better part of 10 hours working at the lab today, Thursday the 23rd, working with my entire class of five on dogs, dog tags, wiring, and assembly. It was a long day, but in the end we got next to everything completed. Here’s how it went.
I arrived at the lab at 11:30. The very first thing I got accomplished was solder the sensor together. Readouts were very well and consistant, hanging below one volt when exposed to alchohol at common air levels, then it would peak to four or more volts when it came in contact with a potent alchohol source at close range. We found that the sensor took roughly a whole minute to stablize the readings before it was fit to sense – a very important note for our wiring (details below).
I grabbed a lunch and drink afterwards. Then we discussed the methodology of hooking up the equipment to the wiring board. It turns out that it is okay to solder wires directly to the pins of the board. The schematic would be very simple, far simpler than what the board is capable of doing. In short, we would program the board so that the dog would turn on or off when achohol levels detected by the sensor would jump over a set threshold.
The threshold was a little higher than 1 volt, common air levels of ethanol, alchohol, etc. The wiring board and the sensor circuit would be powered by a 9 volt battery. When the sensor detects a high concentration of alchohol, conductivity rises, and voltage increases. When that happens and the information is sent to the analog input pins of the wiring board, the board computes it, and sends a charge to a relay to the back of the dog. That relay acts as the on/off switch to turn on the dog. When the tog turns on, he will bark for five seconds before shutting down. The board is programmed to turn the relay on for no more than five seconds. The on/off will continue to function until levels have been reduced.
Because of the use of the relay, we used battery packs to hook them up outside the dog battery holds and taped them to the underside of the tog. The board itself was placed on top, and the sensor was taped to the side of Robodog’s head. Michael did all of the wiring, as he had knowledge in that particular field.
Finally, we discussed the dogtag that we were required to make. I wrote and submitted the pictures to him. I hope it comes out pretty nice looking.
There was a particular complication with the board. After we input the program that Michael wrote, the power from USB to the board completely cut out. At first, we believed that the circuit board overloaded as a result of connecting the sensor system to the board, but my classmates thought this was not possible, being a closed circuit and all. When I got home, I tried putting it on DC power and the circuit was alive. I have no clue if the circuit will ever be reprogrammable again. Hell, I don’t even know if the dog will even work correctly on presentation day in 14 hours. But I believe that the struggle was an exciting one.
At times I feel that I was going to fail the course. Much of the teaching, if any, was not done through the professor. Natalie expected us to have knowledge of wiring and electrical engineering when none of us did. Readings were limited or unprovided. In short, it felt counter-intuitive to be expected to get help from our peers who are just as confused as I was. I certainly wished that there was a little more instruction and a lot less coaching. The jump from basic transistor and motor knowledge of VIS147A to the wonderful world of Basic and wiring of VIS147B is crazy. Without a little straight-foward facts from the professor, we will just continue to second guess the research we do never knowing if what we did was correct.
In total, I spent more than two hundred dollars on this feral dog project. $120.00 for the dog (it’s a 2005 Christmas release!), $75.00 for the wiring board, and several more dollars on other components. I think overall, there are some things I wish I could do more with the project, and I wish I had more professional assistance. After all, universities exist to be melting pots for learning. But 200 bucks?………..well, I did underspend a few other visual art classes. I guess it all balances out.
It’s the moment of truth in 14 hours. We named our feral robotic dog ChemHound, after the word ‘bloodhound’. I’m comfortable that, if ChemHound does not work, we will not fail. Our log of our accomplishments are on this website, the program for the wiring board exists, and records of our construction preserved. The effort is there, I’m proud of the work me and Michael was able to get through given the circumstances. And 14 hours from now, I’m confident I can graduate University of California, San Diego stress-free.
Onw@rd.
