BT problems- MP Edge has 48-52v going to the Bluetooth dongle?

[Slackerman]

Hey folks.

New to the forums.
Having an interesting problem with my brand new Magic Pie Edge rear 700c motor that I got about 4 weeks ago and it was suggested I seek some input from the forums.

First, the set-up.
Bike is running a brand new Magic Pie Edge 700c rear hub with an 8-speed freewheel.
I have two 7s5p Lion 18650 packs I built myself. (fyi. I work as a battery technician rebuilding tool batteries and the like) currently hooked into series for a 52v 10ah pack

The Problem
The Bluetooth doesn't work right, on power up the Bluetooth Dongle lights up solid blue for about half a second the immediately starts to flash/strobe like crazy. It has done this since I first turned it on about 4 weeks ago (the rest of the system worked great!) I kind of gave up on it because the first google responses showed me version problems with android, not a rapidly blinking dongle. so I used the bike anyways with the throttle instead of pedal assist.

After I submitted my support ticket I got the idea from Gary to test the voltage going to the plug. every pin was reading somewhere between 48-52v, the full voltage of the battery pack. No pins look bent an the cable looks to be fine...
I would guess that BT, like usb should be around 5ish volts.

Is there any thoughts what could be going on? all help is much appreciated. 

UPDATE: I have now lost all throttle response and the motor is non operational.

Thank you,
Slackerman

[Bikemad]

Hi andto the forum.

On the lower left hand side of the following diagram, you can see the pin allocations for the five pin connector on the Motor harness that is used for the Bluetooth, USB and the Smart LCD Display:



As pin 5 is supplied with battery voltage, if you had inadvertently bridged pins 4 and 5 with the meter probe while measuring the voltages, there's a possibility that some of the controller's electronic components (and perhaps the Hall sensors in the motor, throttle, and Pedelec sensor too) may have been damaged by full battery voltage being momentarily applied to the +5V circuit. 

This might also explain why the motor is no longer working. 

However, I still don't understand why "every pin was reading somewhere between 48-52v", as the voltage at pin 2 (the ground connection) should still be reading ~0V.

Incidentally, a battery pack voltage of 48-52V seems quite low for a 14S pack, as this equates to an average voltage of just 3.43-3.71V per cell.

Alan
 

[Slackerman]

Alan.
Thankyou for the response and the diagram

My mistake,
When I was testing the voltages I was using a 48v SLA pack, not my lithium.

I have a new controller installed and it still isn't running. I'll look up how to test the throttles hall sensor first and go from there
Again, much appreciated

~Chris

[Slackerman]

Thanks for any input 
So I was able to take apart the thumb throttle to get to the hall sensor and I think I found the first problem.

The green signal wire at rest is only 0.02v and doesn't change when a magnet is present.
So, I'm going to order a new sensor ( or maybe the whole throttle) and then see if the motor runs.

I am a little worried about the sensors in the motor too, think they are bad too?
I've seen mentioned a sensorless mode, is that a thing with the edge? What's the big difference?

p.s Neat trick with the protection on the multimeters probe, and the needle. Also, Germans guys thread was a good read, wish I found it sooner lol

Thanks again!
~Chris

[Slackerman]

UPDATE:

IT LIVES!!!!!

So after reading what Bikemad had to say, I dove into the throttle and found that its Hall Effect Sensor was fried, lame but probably my own fault from what it sounds like.

First,
I ordered some generic ones from amazon.... wrong ones. (shoulda known)

Second,
I did more research to find out there are lots of different kinds of hall effect sensors. So I ordered some Honeywell SS441 sensors from digikey.com.... wrong kind... (they were just on or off, not linear)

Third,
Did more research and ordered again from digikey.com the Honeywell SS495A. bench tested them with positive results!
Installed the sensor and reassembled the bike and nothing.... turned the sensor the other direction in the throttle and I'm back up and running, even from a stand still ( so the senors in the motor did not blow  )

So now the last thing, Back to the BLUETOOTH...
So I don't bridge pins again. Where would be the safest place to test the voltage that would go the the dongle? or would it be best just to plug it in and see what happens?

Thank you,

Chris

[Tommycat]

The blue tooth, throttle sensor, PAS sensor, and motor hall sensors all get their power from the same 5+vdc source. Since it runs, I'd say your good there. But if you'd like to re-check, the easiest without being in a connector would be the 4 wire unterminated wires coming out of the lower 5 cable connector. (see the map above) Red is 5+vdc and black battery ground. Make sure you isolate and insulate all of them when done... See post #40...



Regards,
T.C.

[Bikemad]

Did more research and ordered again from digikey.com the Honeywell SS495A. bench tested them with positive results!

The datasheet for the Honeywell SS49E also lists "Handlebar/throttle position sensing in e-bikes and scooters" as one of its potential applications, I wonder if this also needs to be reversed in the throttle housing to make it work correctly. 

Anyway, it's good to hear that you've got your motor running again.   

Checking the voltage supplied to the dongle should really be done on the dongle connector pins.
Although having the correct +5V feed on the pedelec does indicate that the controller's +5V supply is still working, it does not necessarily follow that the correct voltage is also reaching the Bluetooth connector pins. A poor soldered connection within the motor's harness (or an internally break in the wire) could still prevent the correct voltage from reaching the connector. 

Alan