Can you mix the new Rev electronics system with the old system? For example just use a new REV PDH with the old CTRE PCM…
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We have used a rev pdh with the CTRE pcm, it worked fine, no issues that we found, and I see no reason why they wouldn’t be compatible
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Sure! We ran an all-CTRE setup at Electric City Regional, but added a REV Radio Power Module and Pneumatics Hub for Championship without changing anything else out.
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So long as you’re not using two versions of the same component absolutely. We used the CTRE PDB and PCM alongside the Rev Mini Power Module and Radio Power Module this year.
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I’m not even sure using two versions of the “same-ish” component at once is even an issue. As an example, the pneumatic modules are explicitly instantiated by type so I’m not sure there would be a problem using both at once (it’s sort of an extreme example) - using an explicit solenoid port would be tied to the specific module its on.
I have both a CTRE and REV pneumatic module here - we switched during the build but didn’t actually run both but from the software-side, it seems like you could support a mix (so long as each is at a unique CAN ID which basically applies to everything anyway)
Yup, we used the new PDH with the old VRM (no pneumatics, but the plan would have been to use a PCM).
The only combination you have to be careful to avoid is connecting the same radio to both a VRM and RPM. Aside from not being FRC legal, it wouldn’t work right and there’s no reason for it. The VRM feeds the radio at 12V, while the RPM works at 18V. Either of those is within the range of radio input voltages, but if you connect them together they’ll mess with each other and you’ll probably end up burning something out.
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While I agree with you, I’m not aware of what rule actually makes this illegal. R616 is an “or” which I’d assume means you can use both (previously I believe the barrel back and POE were written as an inclusive “or”). On top of that, at the first event I inspected at this year there was some talk of recommending RPM POE + VRM barrel jack until an inspector spoke up and said their team fried something by trying it.
Are you thinking that it is acceptable to connect a VRM and a RPM to one radio? What advantage do you think there will be by doing this?
The VRM puts out 12 V. The RPM puts out 18 V. Connecting two voltage sources together can make them “fight” each other and possibly damage one or the other. Depending on the internal circuitry in the VRM and RPM, it will at least cause one or both to go into shutdown mode to protect themselves. Electrically, there is no reason to connect both a VRM and an RPM to the same radio.
Previously there was no “or”:
2019 game manual:
R54. The Wireless Bridge (Radio) power must be supplied directly by the 12V 2A output of a CTR Electronics Voltage Regulator Module (VRM) (P/N: am-2857, 217-4245) and must be the only load connected to those terminals.
Here is a graphic that shows the (exactly 4) legal ways to power the robot radio in 2022:
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Can you point out the specific rule that makes using an RPM & VRM on the same radio illegal? As I said in my previous post, I had multiple LRIs recommending using both at the first event I inspected at (neither of which had experience with the new rev control system afaik). I’m well aware of the bad effects of such (and as I said, a fellow inspector who’s team had the new rev components fried one by trying it), but I’m not sure if it’s exactly against the rules. I never ran into a team trying it this year, so it never crossed my mind as to the legality of it.
R616 *Power radio as specified – Part 1. The wireless bridge (radio) power must be supplied by either:
A. the 12V 2A output of a CTR Electronics Voltage Regulator Module (VRM) (P/N am-2857, 217-4245), as shown in Figure 9-13, and must be the only load connected to those terminals or
B. using an Ethernet cable between a REV Radio Power Module (RPM) (P/N REV-11-1856) and the “18-24v POE” Ethernet port on the wireless bridge.
and its blue box,
Note that this prohibits using any other active POE injector device to power the radio but does not prohibit using any PASSIVE CONDUCTORS to inject the VRM power into an Ethernet cable plugged into the radio port labeled “18-24v POE.”
The “either/or” here could be is exclusive, which prohibits mixing the VRM and RPM.
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Is exclusive.
The diagram linked above was created by me and used in both the CSA and RI training from what I was told. Those were the only four legal methods to power the radio.
As for causing the radio power components to release their magic smoke by using both… uhh… not likely. More likely is that the radio was bad or the wiring was.
But hey, I’m not an LRI… I’m just a guy with striped pants.
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