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Mystery of Green and Blue light

A project log for Automatic Diet Tracker

You wear it and it tells you if you are loosing weight or not.

MarekMarek 08/24/2014 at 19:120 Comments

I know the title sounds really mysterious, but just have a look at the gathered data.

(Date Time R_max R_min G_max G_min B_max B_min Ir_max Ir_min)

2014/8/23 0:39:55 55 49 1 0 1 0 25 22

2014/8/23 0:59:1 84 73 2 1 1 0 47 41

2014/8/23 9:7:35 97 87 3 1 2 1 53 47

2014/8/23 9:21:30 105 94 3 2 2 1 48 42

2014/8/23 9:49:25 90 80 2 1 45 0 48 43

2014/8/23 10:0:20 94 84 4 2 2 0 50 44

2014/8/23 10:18:2 4294937202 1601 500 445 226 204 2 1

2014/8/23 10:30:3 89 79 3 2 2 1 47 42

2014/8/23 10:48:44 96 85 4 3 3 2 48 43

2014/8/23 11:5:2 104 93 5 4 3 2 49 44

2014/8/23 11:7:8 79 70 3 2 2 1 40 35

2014/8/24 12:39:49 103 93 3 2 1 0 45 40

2014/8/24 13:20:11 0 0 0 0 0 0 0 0

2014/8/24 19:14:54 91 80 2 1 1 0 45 39  

Red and Ir seem to be correct, they behave normally. The points where values are very high (ex. 2014/08/23 10:18:2) are points where I have moved the device and let incident light in, in other words, the data is contaminated with external light, like daylight for exampl.

Points where value is very low are probably cause by something blocking light emission from the sensor, maybe I forgot to move my sleeve or maybe I had something on my hand right below TSL235R converter.

I can see the blue and green light blinking from the device, so I can exclude possible explonation that what is measured are tiny amount of incident light transmited through the skin.

I will print out the sources and have them checked one more time, it must be something simple, like not resetting the value of a variable or something similar.

Since I'm cutting my fingers to measure glucosis levels I decided to buy something more practical then simple alcohol (for disinfection). It was expensive but much more practical, you can see it on the picture above.

I abandoned making home urine color tests with my homebuild device. It takes too much time and is not very comfortable. I'm not someone who likes having much contact with urine :P. So I decided to try to find some test strip that are capable of veryfind urine specific gravity parameter, which can be related to body hydration.

If anyone has an idea how to explain the blue and green light phenomena, let me know in the comments.

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