REV PDH batch 12/22 battery voltage monitor problem

Technical Electrical
1

Hello all, @democat and I think there may be some problems with the 12/22 PDH batch.

For us (7125) the PDH works perfectly normal, except that the battery voltage monitor seems to be very very messed up.

With a fresh battery, that the DS states is roughly 13 volts will register as such on the PDH

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After dropping to low 13, high 12 volts all the way to low 11 volts, the PDH gets fully stuck displaying only 12.0, and nothing else.
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When the battery drops to low 11V the PDH will finally get back to displaying a number other than 12.0, but its super super glitchy and it doesn’t feel right.
The battery during this according to the DS was at 11.7 dropping to 11.4 when compressor came on.
(Don’t mind the compressor I just put a leaky plug in it while we were working)
Video of 12.0 dropping to 11.4 when compressor turns on.

You can also see the PDH freaking out in the latter half of this clip.
If anyone else has any info about this, please respond and let me know.

5 Likes
2

Some additional videos:
https://drive.google.com/file/d/1h6FAPEMA6rcMWtLoVzqcqPP3Ss7Nb5KB/view?usp=drivesdk

https://drive.google.com/file/d/1MWIbhiIRfOIA8mcOao-PBcO0gPQLIjIU/view?usp=drivesdk

3

Also our PDH does not have a flashing white LED (yet) but yours does.

1 Like
4

Can confirm that us and 3 other teams I’ve chatted with have also seen the issue. If you email REV you should be able to RMA this. Unfortunately for us its a pain to replace this close to competitions and we’d rather just bite the bullet on this issue since so far it has only affected the display.

You stated the PDH also freaked out, what behavior did you see? I can’t tell from your clip.

@Greg_Needel @dyanoshak are aware of the issue.

5

Not necessarily flashing, but just solid white status LED, and the breaker lights are all off.

6

yes, sorry its a really bad clip of whats happening, as its not why I was recording that clip, I just happened to notice the display while watching over my clips from today. It seems to just be flickering between some 11.x value and 12.0

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Yea I’m not sure that this is an option for us atm, given the fact that we only have one PDH, we would have to switch back to a PDP, then switch back again to the PDH when we get it back and its really not worth the effort.

If there was some way REV could get an RMA to us at an event because they are also based out of TX we would probably take that offer, but that seems unlikely lol.

Also sorry, really should’ve just made one response lol

8

4422 has the same issue on our PDH. The voltage monitor reads fine until 12.0 volts at which point it refuses to go any lower, though the Driver Station still reports a normal amount. We figured we’d just run with it for the season and hope there’s no other problems with it since we only discovered the issue last week and we compete week 1

1 Like
9

Team 5113 seems to have the same issues, though it refuses to read voltages over 12v, instead of under 12v. Breaker lights seem to work though.

Not really sure if it’s worth it to RMA - seeing it’s only the screen (especially this close to our week 1 comp), but certainly annoying.

3 Likes
10

Would you happen to know what batch these are from, there is a sticker on the back of the board.
Im just curious if these are all from the 12/22 batch or if its a more general issue.

11

Confirming another sticky “12.0” PDH display here. Bookmarking this for now. Way too many higher priorities than this right now . Can’t access the date code right now, but this one came in our rookie KOP.

2 Likes
12

We also have this issue on at least 1 of our 2 new PDHs this year (need to test the other one). We have reached out to Rev and they asked us to go through the whole recovery factory reset routine but did not make a difference, still have yet to hear back from them since.

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13

I just noticed this on our PDH yesterday and thought it was odd. It stuck at 12.0 for a while and then flickered between 12.0 and 12.5 for a bit.

1 Like
14

We are tracking this issue and have a few different units coming back to us for evaluation. If you haven’t opened a ticket up yet please do so.

So far the only thing we have seen reported is the display not being accurate, which is annoying, but doesn’t impact the usability of the device.

Once we get more information into the cause of this, we will publish information on the fix or return/RMA process involved.

5 Likes
15

Thank you for bringing attention to this issue. Ours was also bought around the same time as yours, and it experiencing a very similar problem.

1 Like
16

I’d noticed the battery voltage sticking at 12.0 often, but hadn’t explored whether that was inaccurate. We bought the PDH this year, so could be same batch.

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17

Just confirmed. It is from the 12/22 batch.

1 Like
18

I can add to this an state that ours doesnt display battery voltage at all. Everything functions as intended and the robot operates just fine, however we have no battery voltage screen at all.

19

Do people who are experiencing the issue still get an accurate voltage when polling it in code? Or is it just the display.

20

The driverstation shows the voltage just fine like it always does. Its just the display.