Brand new Cycle Analyst DP v3.1 Speedo stopped working. Please help.

Hey everyone,

I've been searching through ES for some months now picking up tips and generally excellent advice. I've built 2 ebikes over the past 7 months and had much troubleshooting along the way which 95% of the time, I've researched and solved the issues myself. The other 5%, I've reached out to the Ebike community and managed to get going again..

So I purchased a CA DP v3 direct from Grin. I took delivery a week ago and managed to clock up 50 miles so far. All working well with some tuning here and there to suit my needs. During a commute on Tuesday, my CA speedo started showing low mph 3 - 5 or so for about 10 seconds and then went to 0mph and has stayed there ever since. So as you can imagine I'm very dissapointed

I've checked the wiring to the controller and all seems okay. Everything is working as expected, PAS, throttle etc so i've no reason to expect an issue with the controller. I also had this delivered 2 weeks ago. I've reset the CA to it's defaults and this has not fixed it. This evening I took the back off the CA and checked the yellow wire had not disconnected and it hadn't. I checked continuity from the yellow solder pad on the CA circuit board to the end of the plug and this is okay also..

I emailed Grin on Tuesday evening but I guess they're busy as I've not had a response.

I really like the CA and this will not stop me using it but as you can imagine I'm quite dissapointed.

Any help would be really appreciated.

All best
Paul.

Well at least it reads accurately at a stop sign or when the bike it parked

I don't have one, but my understanding it that the CA is using the motor's hall signals to determine the speed. Could it be a problem with the controller not passing through the signals, rather than a fault with the CA?

Thanks E-HP,

Although it's new controller, it's possible that is the problem. I plan on taking the controller apart in the next few days to see if I can find the issue. I'm hoping it's just a dodgy solder joint.

I'll report back my findings.

Thanks for your prompt response

E-HP said:

Well at least it reads accurately at a stop sign or when the bike it parked

I don't have one, but my understanding it that the CA is using the motor's hall signals to determine the speed. Could it be a problem with the controller not passing through the signals, rather than a fault with the CA?

Click to expand...

ax_foley said:

I'll report back my findings.

Click to expand...

Good luck. I'd like to hear how it turns out for future reference. I'm sure at some point I'll get a Cycle Analyst.

And by the way, welcome to the forum!

Since you've already verified the connection from CA PCB to CA-DP connector, then it has to be before it gets to the CA's DP connector. That can be anywhere from the controller side of that connector to the inside of the motor.



CA-DP uses one of the three hall signals from the motor for the speed signal.

This wire is usually connected directly to the same point on the PCB that the hall signal comes into the controller on.

That means that it is likely there is no signal from the motor itself; the hall providing that signal is either disconnected from the controller or failed.

You can test the halls but this requires a pullup from the signal to 5v, normally done inside the controller. Easiest to leave the controller connected and powered on for this test. Multimeter from ground to hall signal pad on controller PCB or back of hall connector between motor and controller will show a toggling voltage as you spin the wheel by hand (bike upside down easiest, usually), when hall working. No toggling = no hall signal (broken wire or broken hall).

If it's a geared hubmotor, you have ot turn it backwards to get the hall signals (motor won't spin forward by hand due to internal freewheel). If it's DD hub, works either way.

There's three hall signals, so if one of them is still working you can simply move the CA's speedo wire from the non working one to the working one.

If none are working then the most likely culprit is either ground or 5v to the halls in the motor is disconnected.




Either way, if the halls aren't working but your bike still does power the motor normally, it means your controller is either sensorless or autoswitching when sensors fail. So you don't have to fix the sensors if they aren't working. (but it might make the bike startup smoother, or run quieter, if it's an autoswitching controller, especially if it's like the Grinfineons and only uses sinewave when halls work).



If no halls work and you don't want to fix them you can get the SA speed sensor from Grin Tech, and solder it into the CA where the speedo wire from the DP plug used to go. If you don't want to solder, you can buy their ConnPack of JST housings and pins, and crimp yourself up a pass-thru 6pin connector that doesn't pass the speedo wire thru from the controller, but does all the others, and on the CA side just crimp in the SA sensor wires to the speedo wire and ground.

Thank you all so much for your responses.

It is now all sorted

I opened up the controller (which is as new as the CA). I followed the yellow wire that the CA plug is connected to into the controller and found it disconnected with a 1K resistor attached. The leg of the resistor had come away fully. I knew that it needed to be connected back to the hall line but getting in amoungst the wores to solder was too tight and i'd do more damage than good. So I soldered a 1K resistor onto a peice of wire, spliced it into the yellow hall wire just outside the controller and boom!!.. all working again..

I've just finished my 13 mile commute and everything is working perefectly.

Thank you all again for you help. I've learned a lot.. Maybe one day I'll not need to ask questions.. but unlikely :wink:

Thanks for following up. :thumb: I'll store that in the old memory bank for when I finally break down and buy one.