The chip is completely dead, incinerating itself. This is the second one that has killed itself. The wiring is correct, using both a custom crimped length, and one that was crimped from the factory. It is plugged correctly into the rio, (analog IO), and the two that have failed so far have been in different Analog IO ports on the rio. The cables are plugged in properly, and 5v is being supplied to all the encoders. Anybody else having this issue?
Time to start probing that RIO to see what is actually on that 5V rail… then check what the voltage potential is at the end of the cable while jiggling the robot around.
Double check everything is good with the cable you have been using. Not just the connectors, the whole cable length.
My money is on something being wired wrong or 12v somehow entering the system through some wiring issue like insulation being rubbed off.
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Sending you a DM so we can get some replacements shipped out to you. The first thing to check would be continuity at the RIO between 5V and 12V and 5V and ground, as Skye alluded to above. Then the voltage potential between 5V and Ground would be next.
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Upon further testing, the RIO Analog 5V-Ground rails are all 5.05V, and the end of the cables were the same voltage. Everything on the robot is grounded properly, the really weird thing is that both ones that died were using different cables and on different AIO ports and swerve modules.
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Huh.
If you know, what were you doing when they let the smoke out? Robot just sit there powered on, driving around? Aggressive cycle practice? etc.
The multiple failures over different cables is concerning. Yes the encoders could be somehow defective, but the other common denominator is the rio 
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I can try another rio tomorrow afternoon. Robot was sitting there, maybe some swerve modules turning as we were testing drive code, but that’s about it.
We’re going to get some replacements heading your way tomorrow too.
Appreciate you letting us know. For folks reading we always want to know about stuff like this so we can help make it right. Feel free to DM me here or you can always email us at [email protected]
Thanks!
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On a different note, since you sell the max spline bearings any chance in you making these at a more reasonable price
With WCP selling a similar spline these could be used for either
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Thriftybot is great at helping making things right. Always quick to respond and correct a situation when called upon.
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Any chance they were plugged in backwards?
Isn’t the way pwm style connection is set up supposed to prevent this from being an issue? (Honest question)
I guess backwards would create a 5v potential across the signal side (by definition) , which in turn really depends how/what reverse voltage protection would exist… Worth some investigation I suspect.
You are right that cable orientation is a dead simple explanation.
Yeah, the positive supply is in the middle, with the signal and ground on the outside pins – so these two would be reversed if the cable was plugged in backwards at one end. The relay pins are nearby as well, but those should normally not be powered. This design is supposed to minimize the potential for trouble.
My thinking is that the failure is unusual and looks like the type of thing reverse polarity might explain, AND this is the type of thing that happens in FRC a lot, in my experience.
I’m really just looking for data. Without the schematic, it’s tough to say what might happen in this scenario, but it’s at least a reasonable theory at this stage. Given that we’re talking about an analog output, I wouldn’t be shocked if this had a problem with the input having an applied voltage on it (in relation to the +ve supply).
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Applying 5V or GND to the signal pin does not wreck the sensor, so that’s not the issue. New sensors have been sent, so that should isolate the issue to a set up issue or two bad encoders.
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We encountered the same situation.
3 out of 8 encoders we ordered at june, have died, all in different ocasions, wiring and mechanisms.
Did you find the reason for it?
Any suggestions to avoiding it in the future?
Were they all running off the same rio? Did you check the things Skye posed above? Other than that, maybe post some pictures or more info so others in this thread can help (TTB people included)
We had 4 of these die on us (amongst other issues such as them displaying absurd values in the millions) in the 2024 season, 2 of which died at competition which screwed up the drivetrain for the entire thing for no apparent reason (no shorts on the RIO or anything), so we just bought cancoders which have worked perfectly for us since.
Failing out of nowhere is not something we have heard happen before. Would you happen to still have them and be able to send them back to us? We will dm a shipping label.
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We have a couple TTB encoders but I’m not sure if they were the ones that broke or not, I’ll check on Tuesday.
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I wasn’t able to find them sorry. They must have been assumed to be the dead ones and thrown out during cleaning
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