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!

 

[TheOtherZilla]

Interesting.

 

[Johnny_V]

Very ingenious. When my Chargemaster craps out on me, I'll give this a try. Thanks for sharing.

 

[Papa Charlie]

I like that. I use the Dandy tricker now with my Sartorius lab scale. I thought about buying the auto tricker, but it may not work with my CP64 model and didn't want the head ache. I also like the ability to set the value without having to weight out the load I want first. I always saw this as a PIA.

Does the Raspberry bring the Bluetooth feature into this or is that a product of the AND Scale?

Looks like I will be able to eliminate a few of the components with the Dandy tricker.

Looks like I have another project on hand.

 

[Ammolytics]

Does the Raspberry bring the Bluetooth feature into this or is that a product of the AND Scale?

As described in the article, I'm using the Raspberry Pi Zero W, which has onboard Bluetooth and Wifi.
Hope this helps!

 

[Papa Charlie]

As described in the article, I'm using the Raspberry Pi Zero W, which has onboard Bluetooth and Wifi.
Hope this helps!

It does thank you.
Looking over the BOM, I think this is the list I need to fill if I use my Dandy for the trickler.


One Raspberry Pi Zero W kit
One Adafruit mini proto board or similar
One 16GB MicroSD card
One Serial to USB cable, except that I will need a USB to 25 pin (Printer Cable)
One Null modem adapter (2-pack), I think I would need a QVS DB9 Female to DB25 Female RS232 Serial Null Modem Adapter
One NPN 2222 transistor or similar
One 1N4001 diode or similar
One 200 Ω resistor or similar
Jumper wires

 

[Ammolytics]

It does thank you.
Looking over the BOM, I think this is the list I need to fill if I use my Dandy for the trickler.


One Raspberry Pi Zero W kit
One Adafruit mini proto board or similar
One 16GB MicroSD card
One Serial to USB cable, except that I will need a USB to 25 pin (Printer Cable)
One Null modem adapter (2-pack), I can purchase either male or female. not sure if I would require this unless it is changing the pin assignments.
One NPN 2222 transistor or similar
One 1N4001 diode or similar
One 200 Ω resistor or similar
Jumper wires

Yeah, that should do it, assuming the Dandy trickler uses a 3V motor.

 

[Papa Charlie]

So with the QVS DB9 Female to DB25 Female RS232 Serial Null Modem Adapter I would just order the Serial to USB cable that you referenced correct?

With regards to the motor, I will have to double check, it has the ability to trickle at two rates. It would be nice to be able to hand trickle through the buttons or have the Pi send the signals. That would require me to tap into the Dandy's circuit board. Have to think on that.

Thank you very much for posting this. Very cool project. Looks like I will placing an order for some components tonight.

 

[Ammolytics]

So with the QVS DB9 Female to DB25 Female RS232 Serial Null Modem Adapter I would just order the Serial to USB cable that you referenced correct?

There are two parts you need, 1) the USB-to-Serial cable and 2) the Serial null modem adapter.

The A&D scales use a rather non-standard Serial port setup, which is why two adapters are needed. The parts I listed were the least-expensive option I could find.

With regards to the motor, I will have to double check, it has the ability to trickle at two rates. It would be nice to be able to hand trickle through the buttons or have the Pi send the signals. That would require me to tap into the Dandy's circuit board. Have to think on that.

If you know what batteries it uses, that should tell you the voltage. Two AA or AAA would be 3V.
You might consider just cutting the wires to connect directly to the Dandy's motor. I'd guess that the speeds on the Dandy are controlled by changing the voltage. The Open Trickler, instead, changes the pulse rate to control the speed of the trickler to make it a software problem instead of a hardware problem.

Thank you very much for posting this. Very cool project. Looks like I will placing an order for some components tonight.

Thank you for checking it out! I look forward to seeing what you can make with it!

 

[TrxR]

Do you have a more i depth instructions on assembly of the electronics?

 

[ballisticdaddy]

Looks interesting but almost 1.5 minutes to trickle 5 grains does seem like a long time..or is it just me?

 

[Ammolytics]

Do you have a more i depth instructions on assembly of the electronics?

In the article, there's a schematic diagram as well as a rendering of a the Pi with all components wired up. There's also some photos of the assembled board. Is there something specific you were looking for that those don't cover? I'd be happy to help if I can.

 

[Ammolytics]

Looks interesting but almost 1.5 minutes to trickle 5 grains does seem like a long time..or is it just me?

A couple of things to keep in mind:

1. I didn't "tune" the trickler before I shot the video because I didn't want it to be misleading. Once tuned, I have it running fast enough that I'm constantly pouring from the trickler/scale into a case and from the chargemaster into the trickler/scale.
2. Since it's a DIY/open design, there are a lot of variables. For example, folks may choose different motors or lengths of tube, etc. One of my next goals is to add a calibration mode which will trickle at various speeds for say, 15 seconds to determine flow rates on their trickler with the powder they choose. Then, it should always perform quite quickly.
3. As I stated in the video, this is just a starting point. Because it's open, I hope to get more folks contributing to the codebase so as to improve it for the world.

Hopefully this helps to clarify!

 

[TrxR]

In the article, there's a schematic diagram as well as a rendering of a the Pi with all components wired up. There's also some photos of the assembled board. Is there something specific you were looking for that those don't cover? I'd be happy to help if I can.

Im assuming you solder all 40 pins on the backside of the Pi board as well as the top side of adafruit board?

Is it possible to see a more close up shot of the adafruit board wiring?

Thanks

 

[mtnman31]

Great project. I'm already vested in an auto-trickler but will keep following this project as I am a tinkerer at heart.

 

[Papa Charlie]

I am placing the order for the components to adapt the open Trickler process to my Sartorius CP64 Analytical Scale.

I am not positive about the cabling between the scale and the Pi unit. According to Sartorius I need a 25-pin D Submini DB25 connector for the connection at the scale. I want to verify the connections as Sartorius makes the following statement in their manual.

Male connector used (please use connectors with the same specifications):
25-pin D-Submini DB25 with integrated shielded cable clamp assembly
(Amp 826 985-1C) and fastening screws (Amp type 164868-1)

!Warning When Using Pre-wired RS-232 Connecting Cables:
RS-232 cables purchased from other manufacturers often have incorrect pin assignments for use with Sartorius balances/scales. Be sure to check the pin assignment against the chart below before connecting the cable, and disconnect any lines marked “Internally Connected” (e.g., pin 6). Failure to do so may damage or even completely ruin your balance/scale and/or peripheral device.


Pin Assignment Chart:
Pin 1: Shield
Pin 2: Data output (TxD)
Pin 3: Data input (RxD)
Pin 4: Internal ground (GND)
Pin 5: Clear to send (CTS)
Pin 6: Internally connected
Pin 7: Internal ground (GND)
Pin 8: Internal ground (GND)
Pin 9: Reset _ In *)
Pin 10: Not connected
Pin 11: +12 V
Pin 12: Reset _ Out *) For remote switch
Pin 13: + 5 V
Pin 14: Internal ground (GND)
Pin 15: Universal remote switch
Pin 16: Not connected
Pin 17: Not connected
Pin 18: Not connected
Pin 19: Not connected
Pin 20: Data terminal ready (DTR)
Pin 21: Ground input for external supply voltage
Pin 22: Not connected
Pin 23: Not connected
Pin 24: Ext. supply voltage input + 12 ... 30 V
Pin 25: + 5 V

*) = Hardware restart

So I am thinking I need an adapter to go from the 25 pin to the 9 pin, Mini DB25 Male to DB9 Female, Male to Female M/F Serial at Modem Mini Adapter Gender Changer Coupler RS-232

https://www.amazon.com/dp/B07KVGFC3W/?tag=accuratescom-20

Followed by the Null modem adapter and the serial to USB cable as you outlined.

Is this correct. I am concerned about Sartorius’s warning above and don’t wish to fry my scale.

Thanks very much for your help.

 

[Ammolytics]

Im assuming you solder all 40 pins on the backside of the Pi board as well as the top side of adafruit board?

Is it possible to see a more close up shot of the adafruit board wiring?

Thanks

Yeah, you'll have to solder on the GPIO header if you use the Adafruit proto board.
I don't have any photos now, but I am planning on soldering up 2 more of them tonight. I'll take some photos or a video along the way and will share tomorrow. Will that work?

 

[Ammolytics]

Great project. I'm already vested in an auto-trickler but will keep following this project as I am a tinkerer at heart.

Thanks!

I am placing the order for the components to adapt the open Trickler process to my Sartorius CP64 Analytical Scale.

I am not positive about the cabling between the scale and the Pi unit. According to Sartorius I need a 25-pin D Submini DB25 connector for the connection at the scale. I want to verify the connections as Sartorius makes the following statement in their manual.

Male connector used (please use connectors with the same specifications):
25-pin D-Submini DB25 with integrated shielded cable clamp assembly
(Amp 826 985-1C) and fastening screws (Amp type 164868-1)

!Warning When Using Pre-wired RS-232 Connecting Cables:
RS-232 cables purchased from other manufacturers often have incorrect pin assignments for use with Sartorius balances/scales. Be sure to check the pin assignment against the chart below before connecting the cable, and disconnect any lines marked “Internally Connected” (e.g., pin 6). Failure to do so may damage or even completely ruin your balance/scale and/or peripheral device.


Pin Assignment Chart:
Pin 1: Shield
Pin 2: Data output (TxD)
Pin 3: Data input (RxD)
Pin 4: Internal ground (GND)
Pin 5: Clear to send (CTS)
Pin 6: Internally connected
Pin 7: Internal ground (GND)
Pin 8: Internal ground (GND)
Pin 9: Reset _ In *)
Pin 10: Not connected
Pin 11: +12 V
Pin 12: Reset _ Out *) For remote switch
Pin 13: + 5 V
Pin 14: Internal ground (GND)
Pin 15: Universal remote switch
Pin 16: Not connected
Pin 17: Not connected
Pin 18: Not connected
Pin 19: Not connected
Pin 20: Data terminal ready (DTR)
Pin 21: Ground input for external supply voltage
Pin 22: Not connected
Pin 23: Not connected
Pin 24: Ext. supply voltage input + 12 ... 30 V
Pin 25: + 5 V

*) = Hardware restart

So I am thinking I need an adapter to go from the 25 pin to the 9 pin, Mini DB25 Male to DB9 Female, Male to Female M/F Serial at Modem Mini Adapter Gender Changer Coupler RS-232

https://www.amazon.com/dp/B07KVGFC3W/?tag=accuratescom-20

Followed by the Null modem adapter and the serial to USB cable as you outlined.

Is this correct. I am concerned about Sartorius’s warning above and don’t wish to fry my scale.

Thanks very much for your help.

First, thank you! I don't have a Sartorious, but I would love to work with you on adding support for it.
Re: Serial pin assignment: It may help to compare with the 9-pin interface used by the A&D. They describe it in detail on Page 56 of the manual: https://www.aandd.jp/products/manual/balances/fz_fx-i.pdf

Since the Sartorious still uses the RS-232 standard, I'd expect it to use standard cables. The manual makes it sound like that may not be the case and I'd have to do a bit more reading to determine what's required.

You may not need the null modem adapter. It all depends on how the specific serial-to-usb cables are wired and the communication protocol.

Sorry that I don't have a better answer for you right now. I'll dig in a bit more this evening and try to find something more helpful.
FWIW: My first prototype used a serial-to-usb adapter that had the wrong interface for the scale, so I just used jumper wires to connect the correct pins. It worked fine for that phase, but wasn't exactly elegant.

 

[TrxR]

Yeah, you'll have to solder on the GPIO header if you use the Adafruit proto board.
I don't have any photos now, but I am planning on soldering up 2 more of them tonight. I'll take some photos or a video along the way and will share tomorrow. Will that work?

That would be great.

Thanks

 

[itchyTF]

Looks like a fun project but according to your article it looks like it's not iPhone compatible yet. If so, any idea when?