Big Changes and Important Progress

There have been exciting changes and big news since the last post. I might break it into several posts to cover everything.

First, let us start with the brain. The initial plan was to use a TI ARM microcontroller to control the spectrometer, run the lcd screen, and talk to the computer. Upon further consideration and careful thought, we have been working with a small, ARM-based SoC from Allwinner, the A13. This will allow everything we need plus more: digital and analog GPIO, native LCD driver, plus all the good bits that a full linux distribution would have (sans X server). I'll detail plans for this subsystem as they come along, but the plan is that this control system will be its own device, that will be embedded in the spectrometer, but be a neat board all by its lonesome. On the software side, this opens up entirely new worlds. With the decision to move to a full embedded linux system, we have also opted to use the QT application framework, streamlining the process for making a fluid and intuitive experience using one of the stablest open source projects in the game.

Next, let's talk about progress on the actual spectrometer. So far it's been really promising. After several iterations of machining the spectrometer profile into polycarbonate, I have arrived at a prototype that I'm very comfortable with milling into aluminum. Compared to theoretical design and calculation, it's at least as accurate as a pair of calipers can confirm, using two separate laser sources (532nm and 650nm). Right now my process involves cutting the curvature into the material and then pasting a strip of mirror film onto the curvature to prototype expensive mirrors, which works for proof-of-concept, but won't cut it at the calibration stage. Anyway, the next step of the game is to get optical mirrors to go with the diffraction grating, and start to contact suppliers in China to source components for prototypes in the near future.this breakthrough has been huge from my perspective, and I'll provide pictures of the prototype later in the week. 

That's all for now, be sure to check out the repo for any updates on circuit diagrams, cad diagrams, and code, and comment if you have any questions.