Trouble with CAv3 & TDCM sensor

[Drizzt321]

So I'm having major troubles trying to get my CAv3 & TDCM sensor to play nicely together and give me a good PAS experience. Frankly, to get much of any PAS experience currently. Originally I had some amount of responsiveness, although it wasn't very good & pulsing a lot, but lately even going back to previous known settings (I save every write to it's own file before writing) I don't get anything.

I see a voltage & Nm change in the CA Live Data monitor, but I'm not getting any power assist when pedaling, nor do I see the little left/right bars going up at all. I've been through section 5.7 of the (un)official manual a few times, including a vaguely accurate torque scaling as per sub-section 13 on TDCM sensors. I just did a data logging on my commute today, and saw all 0's for the RPMs & Torque values. Is there something else to check? Other settings? Should I put in a shunt and use a multi-meter to monitor something? I could get the tools to pull out the sensor from the BB to check something, if that's necessary.

 

[teklektik]

The apparent dropout in your signals looks a little troubling, although hopefully it's just a config issue.

Email your setup file to info@ebikes.ca with a link to this thread or a similar description of the issue. The file will get all the details on the table. I believe this to be a matter best addressed by Justin and the guys at the shop.

 

[Drizzt321]

Attached is the config I had loaded up this morning. I have the eZee rear kit (eZee700R ) from ebikes.ca, CAv3 DPS, C3625-EZ_R controller, TDCM 120 kit.

And like I said, the torque scaling I'd consider only vaguely accurate. I used 2 1-liter plastic water bottles in a small cardboard box. I fudged the actual weight slightly above just what 2 liters of water would be.

 

[justin_le]

I see a voltage & Nm change in the CA Live Data monitor,

Can you tell me what actual voltage values you see, when there is no torque on the cranks and when you squeeze the brakes and apply full force on the pedals?

And similarly, in the Setup PAS sensor high level menu, do you see both the 'P' and the 'D' arrows toggle up and down as you spin the cranks?

Since you say you see 0 RPMs, then my hunch is that there is simply a bad connection on one or both of the quadrature PAS signals. We've seen a few cases where the plastic overmolded plug that comes off the TDCM BB isn't mated fully with the extension cable. It takes quite a bit of force to properly lock these two connectors together.

-Justin

 

[Drizzt321]

Going from memory here, the voltage when no torque is something around 2.42v, give or take. I'll check with full force when I go down to head home.

I don't recall the P & D arrows, although a few weeks ago when I was doing some maintenance I did pull the plug apart to do some wiring cleanup, so maybe I didn't quite fully mate it. I find it very difficult to put those 2 connectors together given their size and such. Poor actual user experience design. I'll double check the arrows and the connection.

 

[Drizzt321]

So the actual static values are 2.52v 2.7Nm with brakes and full force 3.3v 23Nm. This was after biking at speed for about 30min, and are different than what I saw when I first turned it on.

I also flipped the bike and unplugged/replugged the sensor.

D has a down arrow, whatever I do with the pedals
P, when I pedal backwards seems to alternate between up and down. Likewise when I pedal forward.

I can easily put together a 5 pin up by the CA to break out some wires to measure with my multimeter.

 

[justin_le]

So the actual static values are 2.52v 2.7Nm with brakes and full force 3.3v 23Nm. This was after biking at speed for about 30min, and are different than what I saw when I first turned it on.

I also flipped the bike and unplugged/replugged the sensor.

D has a down arrow, whatever I do with the pedals
P, when I pedal backwards seems to alternate between up and down. Likewise when I pedal forward.

Interesting. It will work fine if you switch to the "1-wire" sensor type and then select the "5V = Rev" direction polarity, since in principle you only need the 'P' arrow for the PAS to operate. If there wass a bad connection or tear in the wire or similar in the 2nd PAS signal then the 'D' arrow would always point up, rather than down. I'm presuming that if you unplug the sensor completely from the CA3, that both arrows point upwards?

 

[Drizzt321]

I'll be heading off work in a bit, I'll check if I unplug it what the CA says then. And do a brief test with 1-wire & 5v = Rev.

The wire has a bit of tape wrapped around it where it exits the BB, although otherwise loose in the hole, so I don't think it'd have worn through to cut one or more of the wires. If the above doesn't work, I'll have to do some checking with the multi-meter to see what general voltages I'm getting on each wire as it goes into the CA. Maybe even an oscilloscope :\

 

[Drizzt321]

So, setup as 1 wire & reverse, I get PAS. Strangely, I get some (a very little) while pedaling in reverse as well. The D remains pointed down, the P still alternates up/down. When the PAS sensor is completely unplugged both point upwards. Something else I can check?

 

[Drizzt321]

Also, I'm now not getting any pulsing or dropout like I was when I first installed it. Could you guys somehow have send me a THUN?

 

[justin_le]

So, setup as 1 wire & reverse, I get PAS. Strangely, I get some (a very little) while pedaling in reverse as well.

Yes, that will be the case, since now the CA has no way to differentiate pedaling forwards or backwards, so when you pedal backwards it looks just like you are pedaling forwards but with very little force on the pedals. If you increase the min start watts then when you spin the cranks in reverse very little assistance will go to zero.

 

[Drizzt321]

Ah, I see. Ok, so, something happened with the wires, any suggestions for troubleshooting if it's the cable from the connector to the CA, or if it's the cable coming out of the actual TDCM itself? My only thought is to use a battery and an LED or something to check if the power makes it through a particular wire. Is there details somewhere as to which pin on the TDCM side connects to which pin on the CA side?