Looking for a few beta testers for a (mostly) robotics motor driver

[Comatose]

Hello all,

I've got a new set of motor drivers coming out, and would like a couple or three more beta testers, so I figured I'd ask here. These are bidirectional brushed motor drivers, synchronous rectification/regenerative type drive. 6-24v input (2s to 6s lithium). Inputs are r/c, serial or analog. All configuration is by DIP switches, and connections are by screw terminals. They're protected from overcurrent and overtemperature.

The primary application for these is robots and vehicles, but they're easy to interface for more mundane tasks, like speed/direction control on pumps, automating tools, micro DC cnc machine spindles, and the like. All the modes update about 3000 times a second (except the R/C modes which are limited by the R/C pulse length to more like 300 updates/second max) so they're good as the output stage of a feedback control loop.

Because of the way the drive works, these can not be used to drive non-inductive loads like lamps or heaters.

The first ones out the door are 10 amp drivers, so those are the ones I need beta testers for right now. If you're interested in being a tester, respond in the thread. I'm hoping to release these soon, so beta testers would need to have time to play with them in the next week and a half or so. There will also be a 20 amp released a few weeks later, and a dual 10A version a couple weeks after that.


Attached is a picture. Physical dimensions are 2.25"x1.25"x.75"

*edit* I forgot to mention that our beta testers are actual testers, so if you're in the beta we'll send you one (or possibly two) free of charge in return for an honest trial and evaluation.

[imeins]

How do you feel about Australians ? ;)

Although my need is for a low current device on a robotics platform using LEGO motors to start with and working up from there. If it works well it would actually go to my son who is at college and scraping together bits to build himself a robot.

Regards,

Ingmar

[ALtitudeap]

Perfect. I have a small cnc mill that uses a car motor for its spindle this would be a perfect trial. Have been looking for a good way to adjudt its speed.

[MX]

My daughter's interested in robots, so I've been thinking I'd resurrect an old robot chassis I did a few years ago. It's got two 12v DC gearmotors for drive. I don't think it would be ready in the next week and a half, but if you need a beta tester when the dual 10A version is about ready, I'd be interested in helping test that.

MX

[Comatose]

imeins: Australians and other fairly quick-to-ship-to countries aren't a problem at all. Have any details/web pages on your robots to share? Lego robotics can have really interesting results. I had several robotics classes in college that were pure or mostly lego hardware.

ALtitudeap: sounds good. Do you have any details on your micro CNC you could share? Depending on what motor you're using and at what voltage it might be a better test for the 20A driver. If you're using mach2 or mach3, that would work fantastically set up as a pwm controlled spindle with a direction input, which is provided for in the software.

MX: I'll pencil you in for the dual. For what its worth, all the singles have what I call "Diff-Drive Mix" modes, which you feed the steering and forward/reverse channels into both drivers, and they take care of the mixing internally. Kinda the same functionality as having a dual driver but with the flexibility of two singles, without having to buy a mixer. Those are there in R/C and analog mode. I figure if you're sending serial commands you can handle doing mixing in software.

[kfong]

I'm interested, lots of robot experience, R/C, electronics and high power apps.

Kin

My website,
http://www.embeddedtronics.com/

[MX]

...MX: I'll pencil you in for the dual. For what its worth, all the singles have what I call "Diff-Drive Mix" modes, which you feed the steering and forward/reverse channels into both drivers, and they take care of the mixing internally. Kinda the same functionality as having a dual driver but with the flexibility of two singles, without having to buy a mixer. Those are there in R/C and analog mode. I figure if you're sending serial commands you can handle doing mixing in software.

So there's actually two drivers per single board?

In my original implementation, I just did a pulse stream out and did PWM to get different speeds. That's handled by your Atmega chip now, right? So I could just send a serial command with speed for each drive, correct?

MX

[Comatose]

No, the single drivers have one driver per board. But they have two input channels. So you can feed the speed and the turning R/C pulses or analog values to the S1 and S2 inputs of both drivers, and they'll both mix the channels to yield a left and a right wheel. The two channel input is also used for separate speed and direction control in analog and as an estop in some serial modes.

The dual driver has two drivers per board, of course.

Serial data or a filtered pwm, either works. There's a simplified serial mode where you just spit out characters 0-255 (full forward to full backwards), a simplified serial with slave select (bring the s2 line high on the target driver, send your character, then bring it low) to allow multiple drivers on the same serial transmitter, and a packetized serial mode for multiple drivers with one pin.

[MX]

No, the single drivers have one driver per board. But they have two input channels. So you can feed the speed and the turning R/C pulses or analog values to the S1 and S2 inputs of both drivers, and they'll both mix the channels to yield a left and a right wheel. The two channel input is also used for separate speed and direction control in analog and as an estop in some serial modes.

My brain must not be in gear today :o . Do you have a block diagram or simple schematic showing how you drive two drive motors with one driver?

MX

[Comatose]

Oh, i see where we're not communicating correctly. To drive two motors with the single design you need two of them. They both take the same two speed/direction inputs and mix them to make a left wheel and a right wheel. I'll have an example of this on the site later today in the robotics forum.

[ALtitudeap]

I am using a brute cnc (crankorgan.com) i am using a speed600 car motor right now at 5 volts. but could use more voltage.

[ALtitudeap]

do you have on in the 30 to 40 amp range

[Nightz]

Comatose,
If your still looking for testers, let me know. I am instersted.
I have a couple applications where they may be a good fit.

Thanks,
-Rocko

[shooshoo]

When the dual 10amp ones come out I'd love to test it for you. I have a dual motor pt boat that needs the mixing that you mentioned.

Thanks,
Shawn

[hbsloper]

If you still need testers I am currently building a small laser cnc machine.

Thanks,
Steve

[imeins]

Comatose - give my beta to one of the others in the list please. Something has come up work wise and I'll be too tied up in the next week or two.

:) Ingmar