BiWeekly/Logbook 8/14

Hello! So we’ve come to a unanimous decision that we will try to purchase a premade amplifier/filter if we can find one under $30 at all costs. In the case that we can’t obtain this, we plan to re-evaluate the approach we are using and use a sensitive motion sensor to track blinks rather than look for brainwaves.

I found an integrated chip called the TGAM (it I more than just an IC, it’s a actually a small pcb) that

is sold by the company Neurosky. This chip takes V+-, reference ground, and 1 electrode input. The electrode is meant to go on the forhead while the reference can go somewhere else on the body, although the manufacturer recommends the ear lobe. The chip processes the input on board and outputs. The Neurosky website lists the following specs on the chip

• Raw sampled wave values (128Hz or 512Hz, depending on hardware)
• Signal poor quality metrics
• eSense Attention and Meditation meter values
• EEG band power values for delta, theta, alpha, beta, and gamma

The chip comes programmed with NeuroSky eSense, A/D, amplification off head detection, and noise filtering for EMG and 50/60Hz AC powerline interference

The following sites have more information

http://developer.neurosky.com/docs/doku.php?id=what_is_thinkgear

http://www.seeedstudio.com/document/pdf/TGAM%20Datasheet.pdf

All these things, especially the filtering, were things we failed to get working in out homemade design. It is our hope that this chip will solve our immediate issues and get us back on track. The output goes out as uart at 1200, 9600, or  57600 output baud rate, so easy for the Arduino to handle! The website did not have a list price, only prices for the full headsets that Neurosky develops. I sent them an ‘inquiry’ but they ignored me; instead I ordered a toy off of amazon that uses the TGAM chip, this toy is commonly used for diy bloggers and interfacing it with other things is well documented on many websites. (The MindFlex Toy)

On another note: did you know EEG actually stands for Electroencephalogram? I learned this from the neurosky website.

We’re meeting up on Monday (hopefully) to go over our presentation, we can’t be sure if we’ll have much to show off, but we’re going to film a short clip explaining our project and then itegrate into videos of the working machine (like an advertisement) later down the road.