FRC Blog - 2016 Motor Controllers

[Mr. B]

Will the PG71 Gearmotors offered on FIRST Choice be Legal? Both have a 775 motor on them

[Mark McLeod]

Everything on FIRST Choice is legal by definition. (or maybe not :-) the season rules, rule )
The 775 motors on the PG71's are not Banebot motors which are the only ones that have been discontinued and thus made illegal.

[Jared Russell]

Originally Posted by Mark McLeod

Everything on FIRST Choice is legal by definition.

So that digital multimeter is a legal robot part!

[notmattlythgoe]

Originally Posted by Jared Russell

So that digital multimeter is a legal robot part!

[AllenGregoryIV]

Originally Posted by Jared Russell

So that digital multimeter is a legal robot part!

Seems perfectly legal to me. Not sure what you would use it for but it is legal. Actually it might even be legal as a

"Custom high impedance voltage monitoring or low impedance current monitoring circuitry connected to the ROBOT’S electrical
system is acceptable, if the effect on the ROBOT outputs is inconsequential."

[Mr. B]

I know first hand that this statement is incorrect.
" In the past FIRST Choice components have always been FIRST legal."

[Mark McLeod]

Originally Posted by Jared Russell

So that digital multimeter is a legal robot part!

Only putting a battery in it is illegal on a robot

[Thad House]

Originally Posted by Mark McLeod

Only putting a battery in it is illegal on a robot

Actually, if I remember right, COTS devices are allowed to use their internal batteries...

Originally Posted by cgmv123

Non-legal 2009-2014 control system components were in FIRST Choice last year.

There were no rules saying you couldn't use those parts. Just that they couldn't directly control the robot with them. If you wanted to put a cRIO on the bot and use it for camera processing then communicate to the RoboRIO you legally could.

[cgmv123]

Originally Posted by Thad House

There were no rules saying you couldn't use those parts. Just that they couldn't directly control the robot with them. If you wanted to put a cRIO on the bot and use it for camera processing then communicate to the RoboRIO you legally could.

You could probably have gotten away with a cRIO, but I don't think you could have gotten away with an earlier PDB.

[Michael Corsetto]

Cross The Road Electronics has posted a detailed report of some Motor Controller Output Power Testing they preformed with the four main FRC speed controllers on the market:

• Victor SP
• Talon SRX
• SPARK
• SD540

Link to .pdf document here

Please take note of the test results on page 7. I'm very concerned about the SD540's performance, particularly that the SD540 appears to brown out at 9.5V.

2016 will be the year of the brown out...

-Mike

[Thad House]

Originally Posted by Michael Corsetto

2016 will be the year of the brown out...
-Mike

Programmers better bring their A game this year if teams want any sort of speed with 3 CIMs. Some very intelligent ramping and shifting code is going to be required for all the top teams.

Maybe someone who knows a lot about working with motor controls would be willing to do a white paper or something how how to limit current. Trying to find documentation online on how to do that has been impossible for me.

[Ryan Dognaux]

Originally Posted by Thad House

Programmers better bring their A game this year if teams want any sort of speed with 3 CIMs. Some very intelligent ramping and shifting code is going to be required for all the top teams.

With everything I've been reading about brown outs, I think we're just going to go back to the tried and true '4 CIMs on your drive' depending on the game. It just isn't worth the risk of being dead on the field in a match.

[Jared Russell]

Originally Posted by Thad House

Programmers better bring their A game this year if teams want any sort of speed with 3 CIMs. Some very intelligent ramping and shifting code is going to be required for all the top teams.

Maybe someone who knows a lot about working with motor controls would be willing to do a white paper or something how how to limit current. Trying to find documentation online on how to do that has been impossible for me.

It would be awesome if the Talon SRX gets a firmware update that lets it do this (current limiting). It can already do ramping.

[AdamHeard]

Originally Posted by Jared Russell

It would be awesome if the Talon SRX gets a firmware update that lets it do this (current limiting). It can already do ramping.

Yup Yup.

I'd love this for FRC, and a few non-FRC applications I use Talons for.

[notmattlythgoe]

Originally Posted by AdamHeard

Yup Yup.

I'd love this for FRC, and a few non-FRC applications I use Talons for.

A continuous sensor option would be nice too. Similar to the continuous sensor option in the WPILib PID Controllers.