That might as well be the name of my “Wastebin Project” category. I haven’t done a Wastebin Project in a while so I’m shaking off the dust on this blog category today. This category is for those small random projects that only last for a day. They usually happen without proper thoughtful prototyping. It’s just about getting the creative juices flowing, experimenting, and having fun thinking on the fly.

Anyways, today I wanted to try something I’ve been meaning to do for a while, and that is try to create the smallest mobile robot I can. I also wanted to challenge myself to see what I could come up with in an hour.

I’ve done a couple of mobile robots before. My first robot was “Frank” who won the hearts of many. My second robot, “Greg”, was what I liked to call the Mobile Billboard because it was a rectangular bot with an LCD strapped to it. With my PCB designs that I’ve been posting about for the past little while, I can get a mobile robot to get into an even smaller form. Spoiler: It doesn’t work out, but seeing what doesn’t work along the way was interesting to me.IMG_20140924_154601This was it at the end of the project. If things did work out, I’d swap out the jumper wires for shorter soldered wires to neaten things up. What really was the final nail in the coffin was a wire between the 9v battery holder and my AMS1117 Voltage Regulator Board broke. But that was just one nail, among a few others.

The big thing I learned was that the servo library doesn’t work with the Attiny85 microcontroller because the servo library relies on 16-bit timers while the Attiny85 has 8-bit timers. I’ll have to look into it, but upon some light research it looks like it’s possible. After I realized that, I swapped out my Attiny85 Breakout Board with my Atmega328p Breakout Board. I got the servos rolling, but there was no control or logic behind it.

I wanted to try using a photoresistor instead of the ultrasonic sensor to be the eyes of the bot. I didn’t test the photoresistor so I couldn’t calibrate it. I was just guessing values but none of them worked so I don’t even know if the photoresistor was working at all. I still have the circuit so I can play around with it.

IMG_20140924_155017I kept the chassis because I want to try this again. This is how I always make my chassis but it’s a lot smaller compared to my previous robots.
IMG_20140924_155031This is the photo resistor circuit, as well as the power supply outputs (the headers) for the servos. I’ll play around with the photoresistor and maybe this could be back again in round two.

Thanks for reading! I’m still working out plans for my next project. It should be a light show… Stay tuned!