First thing I want to cover is the name. I started naming my projects since my first conventional Arduino robot, Frank. When I did that, I also named the light show project at that time Helga. Since there was a gap between F and H, I decided to fill it with Greg. I’ll continue the naming tradition probably with my newest light show when it gets its Christmas update. It’s not much of an importance but it brings a nice personality aspect to it. People seem to enjoy it. I thought of reusing the Frank name and declaring it Frank 2.0 but I didn’t go with it because, if I did, I would want the original cardboard smile which I threw out. Alternatively, I like calling Greg the Roving Billboard project.
As I talked about in my last post, I discovered a cheap electronics parts supplier in the province (most of my parts come from out of the province, closest was Quebec). I decided to pick up an LCD display along with the new LEDs that will be going into the light show update. With the LCD here, a short list of goals was created.
The goals were simple. Obviously I wanted to incorporate the LCD display somewhere on the robot. I also wanted a cleaner and more compact design compared to Frank. I’d also have to adjust to not being able to pan the ultrasonic sensor (the eyes) because the servo was recycled into the new light show. Let’s see how I did.
The original idea was to have the LCD sit on the top so that you could read what it was saying without having to bend down to his level to read off of the side. It’s still fine though because the sides would be plain and boring otherwise. This was a compromise, which leads me to the next goal.
With the jumper wires all being 20cm long, it took up a lot more room that I was expecting. I was going to seal the top with the LCD on it when I was finished wiring up but it didn’t work out. The compact design is aided by mounting the Arduino on its side. It also made sense to do this to help balance it with the LCD on the other side.
It was difficult working in such a small space. There is a breadboard buried at the very bottom for distributing the power and for the current-limiting resistors for the LEDs. I also had to make a clearance for the programming cable. Once the cable is removed, I can push the wall back up which doesn’t look all that bad.
I was struggling to get things into place so I ended up having to open up the side with the LCD. I found that a rubber band worked nicely to keep the wall up once the wiring was complete. I didn’t want to tape it in case I had to go back in.
Finally, the lack of the servo for the ultrasonic sensor was no issue. It just always turns in the same direction every time it encounters an obstacle and tries again.
This project worked out as a success in my view.
The first test was hilarious. I quickly found out that it was top heavy and unbalanced. I didn’t catch it falling over on video (because I was too busy laughing at it) but you get the idea of what the troubles were from this short clip:
To fix the problem, I added these paper bumpers alongside the castor wheel. Also, I found that mounting the 9v battery outside on the back using the rubber band helped the balance of it.
I want to take this project further by strapping a couple sensors on it and have it read out information on the LCD… but the wiring may prevent me from doing that. We’ll see. Thanks for reading, and stay tuned for the Christmas/2013 light show update!