[FRC Blog] 2017 Motor (and Servo?) Controllers and MXP

[Bkeeneykid]

Posted on the FRC Blog, 12/16/2016: http://www.firstinspires.org/robotics/frc/blog/2017-motor-controllers-mxp

2017 Motor (and Servo?) Controllers and MXP
Written by Kevin O'Connor, FIRST Robotics Competition Robotics Engineer.
It’s getting to be that time of year where many teams are working on budgets for control system items and planning pre-Kickoff purchases so we wanted to let you know about some changes to legal actuator controllers and MXP boards for 2017.

Actuator Controllers

The complete actuator controller list from 2016 will be legal for 2017:

A. Motor Controllers


Jaguar Motor Controller (P/N: MDL-BDC, MDL-BDC24, and 217-3367)
SD540 Motor Controller (P/N: SD540x1, SD540x2, SD540x4, SD540Bx1, SD540Bx2, SD540Bx4)
Spark Motor Controller (P/N: REV-11-1200)
Talon Motor Controller (P/N: CTRE_Talon, CTRE_Talon_SR, and am-2195)
Talon SRX Motor Controller (P/N: 217-8080, am-2854, 14-838288)
Victor 884 Motor Controller (P/N: VICTOR-884-12/12)
Victor 888 Motor Controller (P/N: 217-2769)
Victor SP Motor Controller (P/N: 217-9090, am-2855, 14-868380)

B. Relay Modules


Spike H-Bridge Relay (P/N: 217-0220 and SPIKE-RELAY-H)

C. Pneumatics controllers


Pneumatics Control Module (P/N: am-2858, 217-4243)

In addition, the following new devices have been approved for 2017:

Digilent DMC60 Motor Controller (Part #: P/N: 410-334-1)

The DMC60 is a PWM motor controller with a 60A continuous current rating, four multi-color LED indicators for feedback, integrated thermal sensing and protection to prevent overheating and damage, and a sealed, ruggedized, and compact aluminum case. For full details, please consult Digilent’s specification sheet (https://reference.digilentinc.com/dmc-60/reference-manual).

Mindsensors SD540C (Part# SD540C)

Mindsensors.com has been a long time mentor of FIRST Robotics Competition Team 540 and designed this controller jointly with Team 540 students. This controller is manufactured in USA. The SD540C is a CAN enabled version of the series of SD540 motor controllers introduced last season, enabling many of closed loop features teams have come to enjoy with other CAN motor controllers. The SD540C will use the new “Device Library” software approach described previously in the Blog (https://reference.digilentinc.com/dmc-60/reference-manual), so check the Mindsensors website (http://www.mindsensors.com/68-frc) for both device and software availability.

REV Servo Power Module

The Servo Power Module from REV Robotics enables teams to use larger and/or more servos on their robots than can be powered from the roboRIO alone by taking the signal from roboRIO PWM ports and injecting external power onto the power wire. As always, read the 2017 Robot Rules carefully to make sure you understand how to use this device legally and what devices may be legally used with it. The Servo Power Module will be available on or before Kickoff on the Rev Robotics website (http://www.revrobotics.com/frc/electronics/).

MXP

The complete active MXP list from 2016 will be legal for 2017:


Kauai Labs navX MXP
RCAL MXP Daughterboard
REV Robotics RIOduino
REV Robotics Digit Board
WCP Spartan Sensor Board

In addition, a new board, the “Huskie Board”, has been approved for 2017:

Huskie Board

The Huskie Board is a board designed by FIRST Robotics Competition Team 3061 and manufactured and distributed by Playing With Fusion Inc. The board provides features including: data logging to micro-SD, breakout of roboRIO PWM and Analog I/O, additional analog input expansion, LCD serial connection, 4 controllable indicator LEDs, a 4-switch DIP switch input, and more. The board and software will be available from the Playing With Fusion website. (http://www.playingwithfusion.com/)

[Bkeeneykid]

Is there something I'm missing, because I see no advantage to the new DMC-60 other than "integrated thermal sensing and protection to prevent overheating and damage". Can someone enlighten me? I figure for only $20 I can get CAN and a SRX with all of it's advantages, or just get a Victor SP.

[bobbysq]

Agreed. The DMC60 apears to just be a Victor SP clone that costs $10 more. The SD540C is intriguing though, having CAN for only $50. I'm not sure it provides much of an advantage over the SPARK still though, unless you want to use more than 10.
Edit: I just noticed that the blog post notes "closed loop features" but the product page just mentions limit switches, which are on the SD540/B, as well as the SPARK. If it does have PID control features it's pretty much game over for the SRX.

The REV servo controller seems interesting, although I can't seem to find it on REV's site. If it's just a single thing for a servo, it might not be worth it, (and one could probably inject more power into the PWM wires by splicing) but if it has multiple ports, it could be cool to have if you had a lot of servos.

[Lil' Lavery]

Curious to see what the 2017 Servo rules will look like. Could kill off the small niches in which the NeveRest 60 had some FRC applicability.

[Bkeeneykid]

Agreed. The DMC60 apears to just be a Victor SP clone that costs $10 more. The SD540C is intriguing though, having CAN for only $50. I'm not sure it provides much of an advantage over the SPARK still though, unless you want to use more than 10.

The REV servo controller seems interesting, although I can't seem to find it on REV's site. If it's just a single thing for a servo, it might not be worth it, (and one could probably inject more power into the PWM wires by splicing) but if it has multiple ports, it could be cool to have if you had a lot of servos.

I also couldn't find the new Huskie board either, and that certainly seems interesting. 3061 posted an image of it on their twitter account, but this is all that I've seen of it: https://pbs.twimg.com/media/CcwNFi2WIAAy5H9.jpg.

Honestly, looking at the DMC-60's manual, it looks like it was trying to be a SP but then they went over budget. $10 cheaper, it would have been great. But hey, it now has four lights. How's that for innovation? I'll get our robot to look even more like a disco on the inside.

I do think CAN offers a lot of advantages over a PWM controller like the SPARK. Assuming they can solve some of the issues that the one amazon review had pointed out (the amazon product page has seemingly disappeared, presumably to replace with the SD540C), I think this could be a great product.

[Lil' Lavery]

The Digilent DMC60 has a much higher maximum voltage (28VDC) than the Victor SP (16VDC), which makes it suitable for a wider range of non-FRC applications. The integrated thermistor would also come in handy in applications with longer run times than ~150 seconds.

The voltage protection features are interesting for FRC. Cutting off the motor's power before the RoboRio browns out could be a positive feature. However the current settings indicate a 5.75V Under Voltage Protection, which is lower than the RoboRio's 6.8V BrownOut Phase 1 condition. Additionally the 5.75V protection doesn't kick in until after 5 seconds. Anyone have any insight into time-based criteria for RoboRio Phase 1 brownouts?
General empirical performance testing when compared against the Victor SP and Spark would also be useful information to have.

[cad321]

Assuming they can solve some of the issues that the one amazon review had pointed out (the amazon product page has seemingly disappeared, presumably to replace with the SD540C), I think this could be a great product.

Although I can't say for certain, it looks as though they've made the new version a little more robust. In the picture it looks as though the case is now injection molded, and some of the connections appear to be more "professional." For me, as long as it functions as advertised and the finished product is held in something more robust than a 3d printed case, I would be happy. This is a motor controller giving you CAN capabilities for sub $50. I think they would make a great addition to a teams arsenal for when you don't need all the power of an SRX, but don't want to deal with adding pesky PWM cables.

[mman1506]

I have a feeling that the DMC-60 might be a Vex OEM product. NI also offers a lot of post secondary educational robotics solutions and it could be an addition to the product line that also has use in FRC. I'd be an odd move for NI to copy something so blatantly. Could anyone from Vex comment?

[Mike Copioli]

I have a feeling that the DMC-60 might be a Vex OEM product. NI also offers a lot of post secondary educational robotics solutions and it could be an addition to the product line that also has use in FRC. I'd be an odd move for NI to copy something so blatantly. Could anyone from Vex comment?

The DMC-60 is not a VEX or CTRE product.

[mman1506]

The DMC-60 is not a VEX or CTRE product.

Wow, that makes me put a lot less faith in the product.

[Nate Laverdure]

Agreed that It's Tricky to see why an FRC team would choose to Run DMCs over the Victor SP.

[Deetman]

Wow, that makes me put a lot less faith in the product considering how NI handled the Jaguar.

The Jaguar was developed and built originally by Texas Instruments (TI) (well technically a company that got acquired by TI). I don't remember National Instruments (NI) doing anything with development or support of the Jaguars, but I could have missed that.

[Greg Needel]

The REV servo controller seems interesting, although I can't seem to find it on REV's site. If it's just a single thing for a servo, it might not be worth it, (and one could probably inject more power into the PWM wires by splicing) but if it has multiple ports, it could be cool to have if you had a lot of servos.

Sorry we were late making our product page public. You can learn more about it here http://www.revrobotics.com/rev-11-1144/

Curious to see what the 2017 Servo rules will look like. Could kill off the small niches in which the NeveRest 60 had some FRC applicability.

We don't know what the rules will end up being but this is designed to allow much larger servos on robots, so I would hope the rules are open enough to allow them. In addition to our Smart robot servo, there are plenty of large scale servos available in the open market.

The real added benefits of this come from cost per degree of freedom, since you don't need a separate motor controller for your servos you can save at-least $45 per actuation over a motor by just removing that requirement. We will all learn in January what FIRST will allow this year.

[Billfred]

I notice the NavX Micro isn't on the legal list, that's a bit disappointing.
The NavX Micro isn't an MXP board (http://firstchoicebyandymark.com/fc17-074).

[pilleya]

The Servo Power Module is a 6V 90W power injector that enables the use of high-power RC servos in applications where a robot controller cannot directly provide adequate power.

There are some really powerful Brushless Servos with steel/titanium gears out in the RC marketplace so this sounds like an awesome addition to the electrical components that FRC teams have available to them.

Some of the High-End Brushless Servo's can be more than $100 so it seems like there could be disparity between what the Servos teams have available to them. But we will have to wait until we see the specific rules.

[Andrew Schreiber]

Anyone know of any extra documentation on what the SD540C gives you?

[Basel A]

The NavX Micro isn't an MXP board (http://firstchoicebyandymark.com/fc17-074).

Yeah figured that out about 10 seconds after I posted (that's always how it works of course)

[Bkeeneykid]

Just found that SD540 review. I'd love to get a statement from any of the Mindsensors or team 540 people on if any of these problems are solved with the SD540C.

Link: https://www.amazon.com/review/R1JCF3G3RLAH92/ref=cm_cr_dp_title?ie=UTF8&ASIN=B01A7B13F2&channel=detail-glance&nodeID=165793011&store=toys-and-games

[mman1506]

Just found that SD540 review. I'd love to get a statement from any of the Mindsensors or team 540 people on if any of these problems are solved with the SD540C.

Link: https://www.amazon.com/review/R1JCF3G3RLAH92/ref=cm_cr_dp_title?ie=UTF8&ASIN=B01A7B13F2&channel=detail-glance&nodeID=165793011&store=toys-and-games

Don't forget this scathing test by CTRE https://www.ctr-electronics.com/downloads/pdf/Motor-Controller-Power-Testing.pdf

[bobbysq]

Don't forget this scathing test by CTRE https://www.ctr-electronics.com/downloads/pdf/Motor-Controller-Power-Testing.pdf

I believe the SD540B has the shutdown feature removed, but the underperformance otherwise is something to consider.

Are there any plans to redo this test with the SD540B/C and the DMC-60?

Edit: The DMC-60 appears to have VERY similar mounting capabilities to the T̶a̶l̶o̶n̶ ̶S̶R̶ Victor SP. The bolt hole distance is the same and there are some zip tie grooves in the same place. It also appears that one could use them as a drop-in replacement for them.

[slibert]

Yeah figured that out about 10 seconds after I posted (that's always how it works of course)

Yes, just to be clear, navX-Micro is definitely legal.

Rather than connect to the MXP port, NavX-Micro connects via USB and I2C and is software compatible with the NavX-MXP libraries. So it's a drop-in addition if you already use NavX-MXP.

Navx-Micro is a great option for teams that have already populated the single RoboRIO MXP port with another MXP board, need a second IMU for turret angle or robot arm angle, or are teams with a limited budget. The 2017 NavX libraries will support multiple NavX-family devices, so you can use both NavX-MXP and NavX-Micro on a single robot - even at the full 200 Hz update rate. And even more, there's upcoming support for video processing latency correction to be released soon.

[Bkeeneykid]

Edit: The DMC-60 appears to have VERY similar mounting capabilities to the Talon SR. The bolt hole distance is the same and there are some zip tie grooves in the same place. It also appears that one could use them as a drop-in replacement for them.

Did you mean the Talon SRX? It says on the product page it's a drop in replacement for the Victor SP, but it's size the same as the SRX. If it was a drop in replacement for the SRX, it should have CAN, but it's too large to be a "drop in" replacement for the SP.

[bobbysq]

Did you mean the Talon SRX? It says on the product page it's a drop in replacement for the Victor SP, but it's size the same as the SRX. If it was a drop in replacement for the SRX, it should have CAN, but it's too large to be a "drop in" replacement for the SP.

I actually meant the Victor SP. It's about the same width, so it should fit in with some clearance for most people's mounting configurations, provided you didn't rely on the length too much. I'm not sure why one would want this though, but if I were to guess, they're just trying to establish a standard for motor controller sizes.

[bobbysq]

Did anyone in the beta get offered to test these? If so, could you try some tests to figure out the general quality of the new motor controllers?

[Mark McLeod]

We haven't seen any for Beta Testing.
Beta Testing this year has been on the software rewrites and updates.

[JStein]

I also couldn't find the new Huskie board either, and that certainly seems interesting. 3061 posted an image of it on their twitter account, but this is all that I've seen of it: https://pbs.twimg.com/media/CcwNFi2WIAAy5H9.jpg.

I want to touch on this quick, as we weren't quite sure of how the timing on all of this was going to work. Playing With Fusion, Inc. will be manufacturing and handling ordering for the Huskie Board - a product of Huskie Robotics, FRC Team 3061.

We expect to have them in stock by about the 30th and will be pushing information to the PWF website this week as it is available (and organized!). Please feel free to contact us with any questions (CustomerService@PlayingWithFusion.com)

-Justin, Playing With Fusion, Inc

[Bkeeneykid]

I want to touch on this quick, as we weren't quite sure of how the timing on all of this was going to work. Playing With Fusion, Inc. will be manufacturing and handling ordering for the Huskie Board - a product of Huskie Robotics, FRC Team 3061.

We expect to have them in stock by about the 30th and will be pushing information to the PWF website this week as it is available (and organized!). Please feel free to contact us with any questions (CustomerService@PlayingWithFusion.com)

-Justin, Playing With Fusion, Inc

I'm certainly excited about this. Two things that I'm personally dying to know

I noticed unlike other MXP board like REV's, there's no MXP pass through, so if my team just got the IMU that plugs into the MXP or another board, we could only have one?
Any idea on estimated price? The $200 of the spartan board always threw me away, but this seems like it could be worth it into that range just because it can do so many really useful things.

[JStein]

I'm certainly excited about this. Two things that I'm personally dying to know

I noticed unlike other MXP board like REV's, there's no MXP pass through, so if my team just got the IMU that plugs into the MXP or another board, we could only have one?
Any idea on estimated price? The $200 of the spartan board always threw me away, but this seems like it could be worth it into that range just because it can do so many really useful things.


1) I'm assuming you mean you want to stack MXP boards. Since the Huskie Board doesn't have a pass-through, this would have to be the top of the stack to work that way.

2) Price for the Huskie Board is $99.95. It's probably worth noting that Huskie Robotics is getting all of the profit on the boards sold. We are assembling the boards 'at or below cost' with components covered by the Huskie team.

-Justin, Playing With Fusion, Inc

[Rich Anderson]

Sorry we were late making our product page public. You can learn more about it here http://www.revrobotics.com/rev-11-1144/



We don't know what the rules will end up being but this is designed to allow much larger servos on robots, so I would hope the rules are open enough to allow them. In addition to our Smart robot servo, there are plenty of large scale servos available in the open market.

The real added benefits of this come from cost per degree of freedom, since you don't need a separate motor controller for your servos you can save at-least $45 per actuation over a motor by just removing that requirement. We will all learn in January what FIRST will allow this year.

I am working on a prototype turret driven by a pixy cam, and am worried about the servo load on the pixy. Would the motor controller be the answer for an arduino server output too? I am thinking of using a parallel 12v to 5v power supply similar to the LED light hookup on the RioDuino. The servo power supply sounds neat if the game calls for servos this year (I would like to use the Smart servos, which we already have in our inventory).

[EmileH]

How come Analog Devices' ADIS16448 isn't listed as an approved device on the MXP, even though it is available in FIRST Choice? (http://firstchoicebyandymark.com/fc17-007)

[Mark McLeod]

How come Analog Devices' ADIS16448 isn't listed as an approved device on the MXP, even though it is available in FIRST Choice? (http://firstchoicebyandymark.com/fc17-007)
FIRST gave us a list of legal MXP all-in-one active boards, not the individual devices we plug into the roboRIO expansion port or the 3rd party MXP all-in-one active boards.
What we plug into them is up to us.

[EmileH]

FIRST gave us a list of legal MXP's, not the devices we plug into MXPs.
What we plug into them is up to us.

Ah, now I understand. Thank you.

[Bkeeneykid]

Another thing to consider is that this is only the approved list of active devices. Under R69 from last year, this is the definition of a active device:

An ACTIVE DEVICE is any device capable of dynamically controlling and/or converting a source of electrical energy by the application of external electrical stimulus.

The ADIS doesn't control and deliver a source of electrical energy, so it wouldn't need to be on this list.

[bobbysq]

I am working on a prototype turret driven by a pixy cam, and am worried about the servo load on the pixy. Would the motor controller be the answer for an arduino server output too? I am thinking of using a parallel 12v to 5v power supply similar to the LED light hookup on the RioDuino. The servo power supply sounds neat if the game calls for servos this year (I would like to use the Smart servos, which we already have in our inventory).

It should be able to act as an output for any device. If I were to guess, it outputs +6V on the center rail and GND and signal are simply passed through.

Also, remember that in competition servos need to be controlled by the RoboRIO.

[Poppeseed]

How come Analog Devices' ADIS16448 isn't listed as an approved device on the MXP, even though it is available in FIRST Choice? (http://firstchoicebyandymark.com/fc17-007)

This list is only for active devices. My understanding from the 2016 rules (R68/R69) is that it's only considered active if it generates motion from the output pins. Something like the ADIS16448 is a sensor, and therefore flals under their passive device label.

You can read more from their blog (http://www.firstinspires.org/roboticsprograms/frc/blog-myRIO-Expansion-Port-Whats-the-Deal)in 2014 if you like, but rules may have changed since then.

[Joe Ross]

Based on the SD540C Library documentation (http://www.mindsensors.com/reference/FRC/html/Java/) it looks like the SD540C is just a CAN enabled dumb speed controller, rather then a Talon SRX competitor.

[bobbysq]

It appears to have a few "smart" features, like getting the limit switch and changing brake/coast while driving. Overall, I think I'd still pick the SPARK over this at the moment, seeing how it offers the same limit switch stop feature (it's not hard to code in anyway) and costs $5 less with the option of buying through Amazon Prime.

However, something to note is that the manual (http://www.mindsensors.com/pdfs/SD540C-User-Guide.pdf) mentions encoder inputs and currently says:
Closed loop Control feature is not available in firmware at this time.
However, you can upgrade firmware of your device to use those
features as soon as the firmware is available.

If they can add this feature soon (and before Kickoff soon, people won't design for features they don't have) and it works well, then the Talon SRX may be seeing its last season of being the dominant motor controller.

[marshall]

If they can add this feature soon (and before Kickoff soon, people won't design for features they don't have) and it works well, then the Talon SRX may be seeing its last season of being the dominant motor controller.

If. (https://en.wikipedia.org/wiki/Laconic_phrase)

[Michael Hill]

So I guess nothing came out of the BLDC motor controller being demoed by CTRE at CMP last year?

[Greg Needel]

I am working on a prototype turret driven by a pixy cam, and am worried about the servo load on the pixy. Would the motor controller be the answer for an arduino server output too? I am thinking of using a parallel 12v to 5v power supply similar to the LED light hookup on the RioDuino. The servo power supply sounds neat if the game calls for servos this year (I would like to use the Smart servos, which we already have in our inventory).

Yes, absolutely. The Servo Power Module is designed to inject power to any servo and pass through the signal line. We do interface with the signal line to so you can read status of each channel via LED feedback, but if you are running a PWM signal this will just work.

It is designed to accept a voltage range from 9-20v. ( 7v is the brownout, but 9v is required to start) We just posted our quick start data sheet so people can dig a bit more into it. http://www.revrobotics.com/content/docs/REV-11-1144-QS.pdf

And Units are available now at REVrobotics.com and soon to Amazon.

[bobbysq]

So I guess nothing came out of the BLDC motor controller being demoed by CTRE at CMP last year?

I'm wondering about this too. Maybe they couldn't convince FIRST to legalize a variety of brushless motors in time? They could also have not finished it for FRC use yet, since it appeared to only have an input for the HERO board.

[JStein]

The Huskie Board is now in full production with virtually unlimited supply over the course of the season. Our inventory shown is "built and on hand", but most backorder quantities will be 3-5 days. The board is available here: http://playingwithfusion.com/productview.php?pdid=88

The Huskies will be releasing more content shortly, so stay tuned!

Happy New Year!
-Justin, Playing With Fusion, Inc