DIY Fraction Finder on a budget

I want to say thanks to everyone for the info that you contribute to the forum as there’s something I learn everyday from you all. This one’s for you guys.

I am a serial tinkerer and always looking for a better way or different route to do things. I know this basic write up will get taken to the next level if you decide to do something with it. cough Budget all in one data logging device cough.

I’ll start this off by saying this is a build that will NOT get you to a 100% stable device that you can rely on a daily basis. It has some clunky programming which will lead to a buffer overflow when running it for a long period of time so it will need to be rewritten to some extent for stability. I have had some cool results using this device during SPD distillations and for around 100-300 or so depending on how crazy you want to get customizing the lights and pcb its a great tool to have around.

There are two ways to building this.

The first way is using:

  1. Arduino uno
  2. as7265x spectroscopy triad sensor (has an integrated UV, IR, and LED light to collect data from the
    410nm-940nm spectrum using electronic shutter)
  3. wires
  4. a computer.
    (optional) i2c shield and i2c connectors for you who don’t like soldering

The sensor connects to the arduino using i2c or spi which is then powered through the arudinos 3v power header. I will post a link to the pre-written python program and arduino .ino file. The computer connects to the arduino through serial. The python program will run and recognize the arduino and show you a graph displaying wavelength and a log count. A mount will have to be 3d printed or CNC machined to hold the sensor in place to the glassware or however you decide to use your new tool.

The second way is using:

  1. raspberry pi
  2. touch screen
  3. spi serial to usb or use your arduino as an i2c serial converter
  4. as7265x
  5. wires
    (optional) i2c shield and i2c connectors for you who don’t like soldering

The sensor connects to an spi serial to usb adapter (maybe can use the GPIO pins on the raspberry pi although there could be issues with this). Then you will have to tell the python program what serial and com port the sensor is using and could run it from there. I will say the Raspberry Pi is glitchy with the current python script so I mainly used it on my microsoft surface.


AMS as7265 triad sensor:
Jumper wires:
I2c shield:
i2c qwiic cable:
raspberry pi model 3 b+:
sd card (class 3) for raspberry pi
touch screen:
housing for touch screen: shortened amazon link

Arduino/python script, screenshots, and a video are here:

ps: Buy this stuff wherever for the best price, I just thought it’d be easiest to buy from one place.

I am working on some other cool projects and will keep you all updated! If you need a cad drawing or it makes sense for me to machine CNC mounts for the sensors its also possible.


I’ve been wondering about this, but was considering different sensors, because that is what I have on hand.

I can’t use the links provided as my router detected phishing attempts.

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Yikes, ok I will upload to google drive. There are a few other sensors that can be used. What do you have on hand?

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I used as my workaround.

Looks good.

I will check the specific sensors I have. They are adafruit breakout boards. The all-in-one SparkFun one is better. Might pick one up to use your code.


Damn @CBNight trying to get all of our information you little hacker. I’m only joking.

Glad you finally are sharing this with the community. Seems like I’ve been seeing this for the last 3-4 months.

Good job little brother. Wish you were still right down the road but we will catch up soon. :beers:


Thanks! It’s fixed now! The adafruit breakout also uses AMS sensors i believe (whether it be an as72651, as72652, or as72653). It should also work with what you have.


Haha you know me man. We’ve been talking about this one for a while. Sounds great brotha :fire:


The adafruit light sensor breakouts I have aren’t the AMS type. I have a few different ones for UV, IR and visible light, but they are cheap, and none of them are probably good enough for this application.

I will probably pick up the one you are using, or this one.


Almost bought that one. If anything it would be better as you could use your own fiber optic light source off circuit board to reduce stray light and then use the electronic shutter signal to open and close a shutter.


Love the idea of this thread. I need me a solution like this. Thanks for opening the conversation @CBNight. Thanks for the contributions thus far @blackie! Lets keep it movin! Cheers


Handheld!! That is so cool! thanks for sharing that.


I’m taking bets…

How many posts got by before someone hates on this project? :thinking:

1:2 - under 100 post
4/5 - under 200 post
2:1 - under 500 post.

Lol. I’m just joking but I know someone gonna come in and say this shit isn’t possible with over the counter tools and hardware.


LOL, there’s always someone that’ll say shit isn’t possible but we can’t let that stop us from trying.


I’ll take the 1:2 under 100 for a stack. If this involves and Chinese part it will be under 50, guaranted. :rofl::rofl::rofl:


You can ask @CBNight. Straight up. I asked him tonight for another project he is working on as long as it’s all Chinese parts. :joy::rofl::joy:. He’s like I’m giving it to you at cost. I said even more reason to make it all china. Trust me. He has another one he’s working on that cool too.

And the part in question for a legit one it’s only like $35. I just wanna China version just to upset people.

I swear I’m the furthest nationality away from Chinese. :joy::rofl::joy:


Thanks for your reply @drjackhughes. Im lame in this area so I appreciate your experience. I didn’t take the same from the article. I guess if I cant see thc then there must be indicators in the same range that we can use? Chlorophyll or sumthin… I dunno, spitballin…


Fraction Finder documentation shows THC above 450 nm. These sensors go down to 410 nm


right? I think its gonna be more doable then thought. You @blackie are one tek smaht mainah bub, respect! I really want a couple of them 901p sensor setups too.


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