The 6.115 Saga

I started work on this project almost a year ago. A majority of what follows happened over summer 2013, as of last week I finished the last task needed to get it to production.

This requires a bit of explanation.

There is a class taught by Prof. Leeb called Microcomputer Project Laboratory, or 6.115 in MIT speak. It runs each spring and students are taught how to work with microcontrollers and then are required to complete a sufficiently complex electronics project of their own design. To aid in this process, each student is given a briefcase size kit which holds protoboards, a microcontroller interface, power supplies, handheld tools, a bag of parts and whatever else they choose to use. It is highly encouraged that the kits be brought home so work can be done outside of class.

The 6.115 kit as used today and 10 years previous.

Motorsports CAN bus

This year I've decided to rejoin the MIT motorsports team. The team designs, builds, and races a car for one of the various FSAE competitions held each year. I was on the team for a little over a semester my freshman year working on a temperature sensor network; it went okay. Now I'm back and the team has switched to the electric competition. My main task is to compact the motor controllers such that they actually fit inside the car. Because that's moving a bit slowly, and in the interest of rekindling the blogging habit, I have a smaller project to present first.

Modern cars have electronics and sensors stuck inside just about every functional part. These bits and bobs need to talk to the main computer and eachother to be useful. Just about every car made after 1996 (and quite a few before then) use the CAN bus protocol for communication. Our car is being made after 1996 so it's going to use CAN bus. To reduce the number of wires running all over the car there will be a breakout CAN node in the front of the car. Last Saturday I mounted and wired the connectors in a laser cut panel I made the week before. It needed to be a custom job because there were all sorts of problems from the board through holes not being big enough to a lack of keyways in the panel.

TL;DR: here are some pictures of a thing I did on Saturday. Just to be clear, I didn't make the circuit or boards for this.

"Branded" boards.

The life and death of Zoran

We got tired of not having a name for the kart so we came up with Zoran. In Norse mythology he's the god of speed and the one who built Thor's Chariot. Charles (dear leader) thought we named our car Zorak, not quite, no. (Just to clarify, Zorak is the mantis in that clip and it's from a show called Space Ghost Coast to Coast).

We put together a logo type thing and engraved it on one of the leg plates. Here's a video showing the process, I suggest you click the little gear to speed up the playback. It prints rasters just like an inkjet, but at least thirty times cooler because lasers.

Raptors

I'm preparing velociraptors for this year's CPW. They're part of a target practice game. Come to Simmons if you'd like to play!

I love me some laser cutter. I pulled the source image from a jpeg then played around with CorelDraw to get a decent vector. The slot construction at the bottom is designed to fit on the back of the seats that are in the Sims MPR. My first test doing the surface details accidentally got sliced all the way through and I ended up with a dinosaur puzzle. Oops. A lot of the paths were being traced multiple times which was causing the cut through. I tried to get Corel to fix it for me but I eventually just sat there deleting lines for a half an hour. I also dialed the power way down. 100% speed, 10% power of 120 watts.

The main reason I went with vectors (as opposed to raster) is the time. I bought enough wood to make 24 of these guys. A raster this size would take at least 20 minutes, probably more like 30. After getting the vector nice (no double lines) each dino took about 5 minutes.

I may try another raptor design if I feel like there's time. Even at 5 minutes each these are going to take 2 more hours to cut. I'm hoping to get some artistic volunteers to help paint them so I don't poke my eye out with a paint brush. Updates to come.

Until next time.