Re: SD540 Motor Controller
 

I was more referring to changing the Brake/Coast state while the robot is in operation using a signal input.

Is there actually an associated connector that goes with the speed controller? Just looking at it, it looks like you're expected to just connect the 3-pin PWM and 2-pin limit switch cables directly into the port at their associated pins (like the front panel button/LED pinouts on a PC motherboard).

Re: SD540 Motor Controller
 

The 16-pin connector is normally used with something like the one in the link below.

https://wwws.samtec.com/technical-sp...iesMaster=HCSD


I looked more closely at the drawing showing the pinout of the connector.

http://www.mindsensors.com/content/7...tor-controller

It does look like one would plug a standard 3-pin connector onto 3 of the 16 pins then plug a 2-pin connector onto 2 of the other pins for limit switches. This is a somewhat dangerous way to do it since if the PWM cable is plugged onto the wrong pins, either the motor controller, the robot controller or both may be damaged. Now I know what aldaeron was referring to when he wrote "It is very easy to plug the PWM into the limit switch pins or vice versa."

Re: SD540 Motor Controller
 

I agree. If we get these, we shall also get a bunch of 2x8 housings and clearly label one long edge with red and the other with green (or something similar) to clearly communicate "this side up" to the wiring team. We might even notch it some way and put our own tabs in place to prevent an incorrect insertion.

Re: SD540 Motor Controller
 

You could also get some 1 x 4 and 1 x 5 housings, insert some female pins and plug them onto the unused pins to block them off. This would allow you to use the standard 1 x 3 and 1 x 2 connectors that you are probably already using. Hansen Hobbies has the needed parts.

Re: SD540 Motor Controller
 

Check out this video of the SD540 in action!!

Re: SD540 Motor Controller
 

Now do the same thing on a 2014 style 6 CIM traction 6 wheel drive that belongs to another team so they can independently beat them up.

Re: SD540 Motor Controller
 

Presuming 6 CIMs are legal in the drive train this year :rolleyes:

::ducks and covers::

Re: SD540 Motor Controller
 

I want to see it on a 2 (1 per side) CIM pushybot with good traction being abused for 3+ minutes with a temperature measurement at the end. I think that's about as "worst case scenario" you can reasonably get for that speed controller.

Re: SD540 Motor Controller
 

That's my point though, the average team that uses PWMs is not going to go out and buy a bunch of these 16 pin connectors (which also adds to the cost of each controller), strip apart the ribbon cables, and splice each one with a 3-pin and 2 2-pin PWM cables, they're going to just plug a standard PWM cable into it, which seems like a terrible idea with this connector.

What's with that shaking/noise in the bot at the beginning of the video? It goes away at about the 14 second mark, and then comes back again at ~24 seconds.

Re: SD540 Motor Controller
 

I would like to hope any terrible rattling you hear is a mechanical problem with their test bot. Though it wouldn't speak well to their quality of building robots (and therefore robot parts), I don't think it should affect your opinion on the motor controller itself. Although, we did have one Jaguar that squeaked at us......

Re: SD540 Motor Controller
 

The test program switches the direction at full speed every 200ms for a given amount of times, then runs for a few seconds and switches direction at full speed again..

This tests the responsiveness of the controller as well as the peak currents on the floating motors. This test was run for 15 minutes without failure.

Re: SD540 Motor Controller
 

Those connectors can be purchased for under $2 each but it would be another part to buy and keep in stock. They take some finesse and knowledge to assemble correctly. It can be pretty easy to short out adjacent wires or get the ribbon cable swapped like the ones for the DIO's a couple of years ago. As the person responsible for teaching the electrical skills on our team, I would not want to have to teach yet another fiddly skill and to have to do QC on it.

Plugging a PWM cable into the 16-pin connector can be dangerous because there is nothing on the case of the controller indicating which pin the Pin 1 of the cable should plug onto. One would have to refer to drawings or manuals which are not always available. It would be best if the cable connection had some sore of key to prevent a reverse connection or at least the product is self-documenting in a way that is clearly visible. The connector being on the side makes it very difficult to use any sort of alignment marks that may be on the enclosure.


There have to be some objective test criteria for any test to be meaningful. What were the heat sink temperatures at the end of the 15 minutes? What were the peak and average currents during this test? Do the currents approach the maximum rated current (or current limit level, if there is such a feature)? What happens if the motors are run at "full power" for 1 or 2 seconds at a time for the full 15 minutes. The momentum of the robot will really come into play making it a more realistic test. How many drivers can switch directions 5 times in one second?

If the temperatures get as high as your published data shows, the service life of some of the parts in your product will drop from years to months or even weeks, most likely leading to failure of the controller. In our practice sessions our drivers will run until the batteries are noticeably weak (typically half an hour, depending on the total number of motors) then they will do a quick swap of the battery (1-2 minutes) and start practicing again. Some of the motors/controllers could be running at full load, essentially continuously, for a couple of hours at a time. I would not doubt that many other teams practice in the same way. Time is precious in this competition. No one can afford to wait for parts to cool down before continuing to practice.

Re: SD540 Motor Controller
 

Can they be purchased without the 3d printed parts in a sort of "Kit"?

Re: SD540 Motor Controller
 

Do you have a particular drive train like that in mind?
If you do I have 2 of these speed controls and a lot of spare parts.
Depending on what you have in mind I may have everything required.

Re: SD540 Motor Controller
 

How many FRC teams have these been beta tested with?

Agreeing with Adam...that's usually what most of us care about.

What is your current inventory like? Supply limitations are usually a big turn-off.