Double power on FRC Radios

Hello! One of our mentors on our team recently mentioned something about possibly having two power inputs on the FRC radios so if one was disconnected during a match the other would still be giving enough power to the radio to not be disconnected and loose comms. Is this something you can do where you can use a POE injector and a REV Robotics radio power module? I am just not sure how this works and any knowledge about the subject would be greatly appreciated! :slight_smile:

I also was wondering if anyone had resources or any knowledge about possible snap on connectors for Ethernet cables so that they are less likely to jiggle out or come loose in a match. If anyone has any resources like that or knows of anything like that please let me know that too please!

Thank you all for your help -
Dom from the N.E.W. Apple Corps.

You are allowed to double power the radio through the VRM(to barrel jack of the radio) and a POE injector, but if you use the Radio Power Module you are not allowed to double power the radio.


These are the 4 FRC-legal [1] ways to power your radio: Legal Options for Wiring your Robot Radio in 2022

I recommend you pick 1 of these 4!

[1] In 2022 and 2023


Good answers above about powering the radio. For the problem of ethernet cables coming loose, there is one solution that we (and a lot of other teams) have employed that never fails…hot glue. Basically, you put hot glue onto the junction between the ethernet cable connector and the body of the thing it’s plugged into (radio, RoboRIO, ethernet switch, Limelight, etc.). This will ensure that it does not pop out accidentally during a match, no matter how hard you get hit. But it’s also pretty easy to strip off the glue when you need to remove the connector for something like programming the radio at the beginning of an event. Just be sure to bring the hot glue gun with you to events to restore the glue for any connector you have to remove. We’ve never had a cable come out (except on purpose) since we started doing this.

It’s rare for these to “jiggle out”. Most of the time, they are not plugged in all the way. Seriously, those connectors are used all over the world in applications that are more extreme than FRC (though FRC probably has some record for most extreme use involving adolescents).

Some key questions for you:

  • Do you make your own cables? If so, why?
  • Do you buy your cables? Where do you get them from?
  • Do the cables have overmolded boots? Are they also filled with plastic/rubber?
  • Do you use cables where the clip/tab has broken off?
  • Do you secure your cables and strain relieve the ends?
  1. We do not make our own cables. Our team decided that since these cables are harder to crimp and make strong connections for that we would just order the closest lengths we need.
  2. We do buy our own cables. In all honesty we have ordered multiple different kinds from different vendors. Most have been ordered from AndyMark but some other ones have been ordered from amazon. I could get a full list of what was ordered and go over it with our supply team members but I currently wouldn’t know where to find the information off the top of my head.
  3. Again, we have multiple kinds of Ethernet cables. Some are and others we have aren’t. This is the main reason we want to use double power on our radio, just for added reliability.
  4. None of the cables we use have broken clips or tabs on them.
  5. We secure all of our cables for minimal strain and do the best we can to make sure all our connections are clipped in properly. To my knowledge all of our cables have strain relief ends to them as well.