gear shift sensor wiring

[martin]

Hi, I would like to fit a gear shift sensor with my mid drive Bewo motor. There is not a dedicated plug for the gear shift sensor but there is a spare 2 pin cable for the brake sensor. I can get a 5 volt feed from the throttle or the PAS sensor, but is it possible to connect to the 3 wires of the gear sensor and make it work? Any advice appreciated.

 

[E-HP]

Hi, I would like to fit a gear shift sensor with my mid drive Bewo motor. There is not a dedicated plug for the gear shift sensor but there is a spare 2 pin cable for the brake sensor. I can get a 5 volt feed from the throttle or the PAS sensor, but is it possible to connect to the 3 wires of the gear sensor and make it work? Any advice appreciated.

Did you test it first by tapping your brake lever while shifting?

 

[martin]

Hi, I haven't connected it yet, I don't know how to wire it in. If only I was at the testing stage! The brake sensors work though.

 

[E-HP]

Hi, I haven't connected it yet, I don't know how to wire it in. If only I was at the testing stage! The brake sensors work though.

I meant can you shift using the brake sensors, since you want to tap into that circuit, you could try to see if the brake circuit functions well for shifting (before attempting the mod).

 

[martin]

Hi, yes, just a light touch on a brake lever will cut the motor to allow a gear change, that works fine.

 

[TommyCat]

Hi Martin,

If your system operates similar to a Bafang Mid Drive, then yes you can wire up your gear sensor to the braking system.
Look at the description here...

https://lunacycle.com/gearsensor-for-bafang-mid-drives/ and it's manual...

https://www.electricbike.com/manuals/gearsensor-manual.html

To the particulars...

The braking switch that uses the two wires, short the brake signal to ground On the Bafang there are 3, but the 5vdc line is not used. (Bafang but typical)

Now to the gear sensor...

It uses a 5vdc supply and ground for operation, two of the three wires. The third is connected to the brake sensor line. Upon operation of the gear sensor, it's electronics will short the brake sensor wire to ground. Also illuminating the sensor LED for a moment. The timing of operation (motor cut-out) depends on the model of gear sensor.

I do not know the wiring pin-out or color of the wires for the gear sensor. But if you have a Bafang gear sensor (with connector), the fact that it can connect directly to the brake connection shown above should help. If you know, or when you figure it out. Please let me know There is a wiring diagram I'd like to get it on. Thank you.


Regards,
T.C.

 

[martin]

Thank you, Basically then as I understand it, one gear sensor wire is the 5v supply, one is both ground and one of the brake wires, and the third is for the other brake wire. I imagine that the light will come on when the power and ground are connected which means that the remaining wire is a brake connection. I don't think I can damage the controller or the sensor by playing about. I will report back, it will be a week or two.

 

[martin]

OK, I have got the gear sensor and attached an extension cable which I have cut open to expose the 3 wires. If we label them 4, 6 and 8 as for the brake harness diagram, using a 9v battery, the power wires are 6 (positive) and 8 (negative), connecting these gives a green flashing light. If you pull a cable through the sensor a red light flashes and a connection is made between wires 4 and 8. So in theory it should work when on the bike and wired up.

 

[E-HP]

OK, I have got the gear sensor and attached an extension cable which I have cut open to expose the 3 wires. If we label them 4, 6 and 8 as for the brake harness diagram, using a 9v battery, the power wires are 6 (positive) and 8 (negative), connecting these gives a green flashing light. If you pull a cable through the sensor a red light flashes and a connection is made between wires 4 and 8. So in theory it should work when on the bike and wired up.

I'd call that good proof of concept testing. Good luck, and don't forget to report back!

 

[TommyCat]

Sounds great! Bonus if you give the wire colors. :wink:

 

[martin]

These are only the colours from the extension cable: 6 red 8 black 4 blue. I will certainly update when installed. Thanks for the help.

 

[A2DA]

Hi Martin
Did ever solve your problems with the gear shift sensor ?
If you didn’t, I have a solution for you that work right now,
Just let me know.... please you do not need to spend no more money....

 

[martin]

After all that I haven't bothered with the gear sensor, I seem to be managing ok by just stopping pedalling briefly, which keeps things a bit simpler.