DIY Gyre Controller Idea

[erk]

I currently have a Gyre pump and while I like its ability to move water, I don't like the simplistic flow control. Since the motor is a BLDC using BEMF control, I thought why not look into what options are available. Seems there are options, but all fairly complex until I found the following from TI:

http://www.digikey.com/product-deta...m-pQCQ3ZTt6QK8i24nfmOYCQ1SUb-6cD_9hoCPH3w_wcB

http://www.ti.com/lit/ug/slwu083a/slwu083a.pdf

Their sensorless BLDC chip on a demo board ready to go. Employs 5V PWM for speed control and allows forward and reverse control as well as lockup and thermal protection. I'm really tempted to buy one of these and see what can be done. I'd love to be able to drive the motor from my RPi/Arduino controller. I really want to implement a sine wave flow pattern that simulates ebb and flow of the waves with surges once or maybe twice a day to emulate tidal shifts. Something like A + B*sin(t/43000) + C*sin(t/10). Time is in seconds. A, B, and C can be time varying to simulate randomness or be a randomly changing amplitude.

Has anyone else considered the TI sensorless BLDC controller? Any obstacles you may see that will get in the way? I'm already aware of the BEMF constant, but that can be approximated thru experimentation. Just looking for input and if you know of any obstacles that may be impossible or very difficult to overcome.

 

[erk]

I decided to go ahead and buy the eval board anyway. I figure I can use it for BLDC motor development on other projects if it doesn't work out for this project.

 

[erk]

Just wanted to update this thread for anyone interested. I got the eval board and it is extremely small and simple. It has an empty pad to connect a 5V PWM signal.

My next steps are:
- Wire pump motor to protoboard
(I bought an extension cable for the Gyre. I'll cannibalize it for this project)
- Power source for the board
(I have some 12VDC wall worts I can scavenge for this)
- Create COM channel using wye resistor network
(I'm hoping I can find the wye network of resistors on the Gyre controller, but if not I can just do trial and error till I find the right resistance.)

I know the XF150 uses 24VDC to power the board. I don't plan to run the pump anywhere near it's max output and hope that 12VDC works fine. I may discover it doesn't and will need to get the 24V eval board. I did find out when I opened the Gyre controller that it utilizes the 6 power mosfet design for Back EMF BLDC motor control. This is definitely possible to do, the issue now is finding time.

 

[erk]

Time to revisit this thread. I never hooked up the TI BEMF BLDC controller because it was for 12VDC, not 24VDC. Since the Gyres are all 24VDC, they wouldn't run as efficiently or possibly even run with the load.

BUT...

TI has a 24VDC controller!

https://www.digikey.com/product-detail/en/texas-instruments/DRV10983EVM/296-38466-ND/4996090

And this comes with easy to connect terminals and a way to communicate over I2C with a PC. This isn't a solution for the average reef keeper, but for those of us that created our own controllers, this would give us the ability to add pump control to our systems. This controller would also work for any 24V sensorless BLDC pumps. I checked the BRS site and the Sicce SDC would be an option, but you'd have to limit it to 3A max.

 

[erk]

I'm pretty excited. The DRV10983 works like a charm. I can control the motor with the potentiometer very nicely. The board also has a PWM input. This means I can control the pump however I want. I created a quick video of it in work and will upload it as soon as possible. It would be nice to create a board specifically for this driver. I may try to create a small carrier board for this driver or see if someone else will.

Here is a pinout diagram of the DRV10983.

 

[McPikie]

I'm pretty excited. The DRV10983 works like a charm. I can control the motor with the potentiometer very nicely. The board also has a PWM input. This means I can control the pump however I want. I created a quick video of it in work and will upload it as soon as possible. It would be nice to create a board specifically for this driver. I may try to create a small carrier board for this driver or see if someone else will.

Here is a pinout diagram of the DRV10983.

I know nothing of electrics, but is this basically a custom control kinda thing where you can adjust and set everything from a tablet/PC and then leave alone?

 

[doughboy]

I had worked on a similar project, but used atmega chip (used in arduino) with some bare metal programming. I was going to use it for controlling Jebao DC pump. I got it to drive the motor, but never finished the project. There are complete BLDC motor controller boards you can buy on ebay that will work on DC pumps for like $10. They usually have the speed and direction inputs.

 

[erk]

I know nothing of electrics, but is this basically a custom control kinda thing where you can adjust and set everything from a tablet/PC and then leave alone?

You would need to do a bit of work to get it to that point. First need an interface that outputs a PWM signal and can connect to the WiFi. Then have to write some code/gui to adjust flow settings on the fly.

 

[erk]

I had worked on a similar project, but used atmega chip (used in arduino) with some bare metal programming. I was going to use it for controlling Jebao DC pump. I got it to drive the motor, but never finished the project. There are complete BLDC motor controller boards you can buy on ebay that will work on DC pumps for like $10. They usually have the speed and direction inputs.

I never could find anything that could control sensorless BLDC motors online. Granted that was a over a year ago. I'm sure others have come up with new driver boards. The best part about the TI driver is it's compactness. An entire 6 MOSFET driver and buck converter in a single analog IC. And the preferred input is 5V PWM signal instead of 0-10V reference.

 

[peterj66]

Very interesting find. Not that expensive either. Planning a modular controller build and this chip definiteky will come in handy.

 

[erk]

Very interesting find. Not that expensive either. Planning a modular controller build and this chip definiteky will come in handy.

I contacted Pololu about making a BLDC controller using the DRV10983. They came back with some interesting news. They are currently working on developing some BLDC controllers, but were not aware of this driver. I did explain my reasoning for preferring this driver, so maybe Pololu will develop a carrier or full up driver board.

 

[Ranjib]

@erk if this works on 5v pwm, then i can drive this straight with reef-pi, since we generate straight 16 channels 5v pwm using pca9685.
Silly question, how this is different from using something simpler like l293d (dual hbridge + darlington ??)

 

[Ranjib]

This is super exciting . Thank you for sharing,
Godspeed.

 

[erk]

@erk if this works on 5v pwm, then i can drive this straight with reef-pi, since we generate straight 16 channels 5v pwm using pca9685.
Silly question, how this is different from using something simpler like l293d (dual hbridge + darlington ??)

This link from Digikey gives a good explanation, better than anything I can say.

https://www.digikey.com/en/articles...ntrolling-sensorless-bldc-motors-via-back-emf

The main point is how to sense and compare the bemf from the inactive phase. The main method is using a 3 phase H-bridge. The L293D has only two H-bridges in each IC and doesn't include the buck converter. The DRV10983 contains the 3 phase H-bridge circuit and all the power and sense electronics in one package and includes a PWM input. The PWM input is probably the most interesting part of all this. A digital rather than analog control as part of the chip. There is also the fact that I don't need to create a wye sense circuit connected to my three phases. That is all inside the chip. I don't need to convert my digital output to a 0-10V output. Essentially a plug and play driver for sensorless BLDC motors.

 

[Ranjib]

This link from Digikey gives a good explanation, better than anything I can say.

https://www.digikey.com/en/articles...ntrolling-sensorless-bldc-motors-via-back-emf

The main point is how to sense and compare the bemf from the inactive phase. The main method is using a 3 phase H-bridge. The L293D has only two H-bridges in each IC and doesn't include the buck converter. The DRV10983 contains the 3 phase H-bridge circuit and all the power and sense electronics in one package and includes a PWM input. The PWM input is probably the most interesting part of all this. A digital rather than analog control as part of the chip. There is also the fact that I don't need to create a wye sense circuit connected to my three phases. That is all inside the chip. I don't need to convert my digital output to a 0-10V output. Essentially a plug and play driver for sensorless BLDC motors.

So, This saves the opamp for analog conversion and also gives more safety. Nice . I have not hooked up my jebao powerhead yet with reef-pi. I was planning to use simple power mosfet. Keep us posted on your build. I'll definitely try to control a gyre in future

 

[doughboy]

I never could find anything that could control sensorless BLDC motors online. Granted that was a over a year ago. I'm sure others have come up with new driver boards. The best part about the TI driver is it's compactness. An entire 6 MOSFET driver and buck converter in a single analog IC. And the preferred input is 5V PWM signal instead of 0-10V reference.

https://www.ebay.com/itm/DC-12V-24V...615878&hash=item2819d4da8b:g:t5wAAOSwqBJXVVC~

these boards have been around for years.

 

[peterj66]

https://www.ebay.com/itm/DC-12V-24V...615878&hash=item2819d4da8b:g:t5wAAOSwqBJXVVC~

these boards have been around for years.

Wasnt there some kind of issue with getting that board to work?

 

[doughboy]

Wasnt there some kind of issue with getting that board to work?

so you follow my diy thread on RC?

this board does not run the pump to the same max output as stock pump controller. unless you run your stock controller at full power, then it is a non issue and solution costs about $10 and is available now.

The TI chip looks like an excellent chip.

 

[erk]

https://www.ebay.com/itm/DC-12V-24V...615878&hash=item2819d4da8b:g:t5wAAOSwqBJXVVC~

these boards have been around for years.

I wish I had found that in my previous search. When I searched for sensorless BLDC drivers, I must have missed it. That board is basically the TI chip. The only thing I'm confused is what does it mean by signal? Is that 0-10V or PWM or 4-20mA?

 

[erk]

So, This saves the opamp for analog conversion and also gives more safety. Nice . I have not hooked up my jebao powerhead yet with reef-pi. I was planning to use simple power mosfet. Keep us posted on your build. I'll definitely try to control a gyre in future

The DRV10983 can handle any 24V BLDC motor up to 40W. So if the Jebao uses a 24V power supply, you could use it. Just might not get full flow. Since the XF150/250 uses 60W max, I'm not getting full flow out of it either. But that is fine for me and my 40B. This driver could also be used for the new Ice Cap gyres, specifically the 1K.