Open Trickler: The DIY Smart Powder Trickler

[ammolytics]

Hey everyone!

I wrote an in-depth article about a project I've been working on -- the Open Trickler!

https://blog.ammolytics.com/2019-04-30/diy-smart-trickler.html

In this article, I describe how I built it, how it works, and how you can build your own for under $60! The project is open-sourced and it uses off-the-shelf components. The controller was written with NodeJS and the mobile app with Flutter.

I hope that this content is high quality enough to justify the time you spend reading it, and how much time it took me to create it!

I’d love to hear your feedback and answer any questions!

 

[bluebie]

Very cool project dude, nice to see hackers getting into this space!

 

[ammolytics]

Very cool project dude, nice to see hackers getting into this space!

Thanks!

 

[flyer]

I like it but I think there has to be a better way to attach the vibrator.

Maybe use a .32 H&R Magnum case or an M1 Carbine case to fit over the trickler tube and drill out the primer pocket to fit the motor.

 

[ammolytics]

I like it but I think there has to be a better way to attach the vibrator.

Maybe use a .32 H&R Magnum case or an M1 Carbine case to fit over the trickler tube and drill out the primer pocket to fit the motor.

I'd love to find a better way, especially if it uses parts that are easy for anyone to find.
I don't have either of those cases lying around, but I may try a .223 or .308 case to see if they'll work.
Honestly though, you could just zip tie the motor to the outside of the tube and plug one end with a screw and it'd work just as well.

 

[ammolytics]

Quick update: A lot of progress has been made on the OpenTrickler project over the past couple weeks (holiday vacation).

- An iOS app is ready for testing (PM me your iOS email address if interested)
- A ready-to-go microSD image can be downloaded and flashed
- The OpenTrickler code lives on a FAT-32 partition, allowing the microSD card to be used as a USB drive. You can tweak the program from any computer (Windows, Apple, Linux)
- If you set it up with WiFi, you can view the OpenTrickler debug and system logs from your web browser

It was a ton of work getting to this point. I learned a lot of new things along the way and I feel very proud of the progress that's been made.

 

[kclo4]

I know this is a bit of a necro-post but I was wondering if there was any other serial interface scales at a lower price point than the FX-120i's. Something maybe better than the usual chargemaster but not $500+.
Great project.

 

[ammolytics]

I know this is a bit of a necro-post but I was wondering if there was any other serial interface scales at a lower price point than the FX-120i's. Something maybe better than the usual chargemaster but not $500+.
Great project.

The project is definitely alive and well! Most of the conversations about it happen over on GitHub:
https://github.com/ammolytics/projects/issues

You're not the first to ask about other scales. It shouldn't be too hard to support others that have serial cable support. See more in this ticket:
https://github.com/ammolytics/projects/issues/35

Obviously, it's not cost effective for me to buy a bunch of scales and make them all work, so I'm leaving this work up to the community.

It's also worth noting that the most recent SD card image for this project makes the code accessible when you plug the card into your computer. This lets you customize and tweak it very easily without having to understand the Linux system that runs it. Debug logs are available through your browser while the device runs, so you can see if your code changes work or are broken.
https://github.com/ammolytics/projects/blob/develop/trickler/peripheral/README.md

 

[ammolytics]

Hey everyone! I created a Discord to make it easier for folks who are building an Open Trickler to chat with and support each other.

Discord - A New Way to Chat with Friends & Communities

Discord is the easiest way to communicate over voice, video, and text. Chat, hang out, and stay close with your friends and communities.

discord.gg

This invite link expires in 1 day to keep out spammers, but feel free to email me directly and I'd be happy to invite you!

 

[A5scott]

Pretty cool project.
Is there a way to change the feedback loop? Rather than hooking into the back of the scale, have an iPhone or other type of camera read the digital readout on the front and trickle accordingly? That would be useable with any digital scale.
Thanks,
Scott

 

[ammolytics]

Pretty cool project.
Is there a way to change the feedback loop? Rather than hooking into the back of the scale, have an iPhone or other type of camera read the digital readout on the front and trickle accordingly? That would be useable with any digital scale.

Interesting idea! The main two reasons for connecting directly to the scale are 1) speed 2) reliability.

Regarding speed, the A&D scale can be configured to update the display 20 times per second. Doing the image analysis that fast on your phone would be tricky.
Regarding reliability, a text value of the exact weight on the scale is the best-case scenario. OCR and image analysis depends on a lot of things (camera quality, image quality, lighting conditions, text framing, font being used, etc) to try and get close to the right value. It also struggles with decimals -- I know because I tried something similar just using the Google Goggles app on my Pixel 2 when trying to read values from digital calipers. It got it right about 1/10 times. Frankly, when it comes to pouring gunpowder, I'd want something more reliable than that.

All of that said, I don't want to discourage you -- everything is worth exploring. Even if it doesn't work out in the end, you'll still have learned a lot in the process!

There are other folks talking in the Discord about machine vision as a way to use a balance beam scale -- hop on in and join the fun!

 

[A5scott]

Oh I bet it would be a lot slower with the camera reading the scale. There has to be a way to program it so that it reads 4 or 5 digits and eliminates the decimal, so the last two characters would be programmed to be the tenth and hundredth place.
I completely agree that a hardwired link is way more reliable, accurate, precise and faster. Just thinking out loud about a way to have it compatible with any scale including beam scales.
I’m not a programmer but that simulation and control class from engineering school 25 years ago was popping into my head lol

Scott