Turning the lights on stops motor assistance

[lightcore-x]

Just tested and this is still the case using the latest firmware. Also, when the lights are turned on and the bike is stationary the power indicator on the display toggles between 0 and 10W.
@casainho maybe you can reproduce this issue if you add some load to the light output wires?

Steps for reproducing:

• Start driving with lights turned off, assistance works perfect.
• Turn light on and keep pedalling, assistance keeps working (don't know how long).
• Stop pedalling for a while, assistance is stopped and won't come back until you turn off the light again.

For me this is a serious issue as it already starting to get dark earlier by this time of the year. This also means that I don't have a lot of time to test new features at night...

[pawpie]

I have lights installed and will try this for myself...will probably only be able to try it next week as my new tires don't arrive until later this week (and current tires are too big for this frame)

[casainho]

@endlesscadence, can you understand if is a problem related to hardware?? Like do your lights work as usual??

When motor assistance stops, can you please look at the relevante variables like duty-cycle and human power??

[lightcore-x]

@casainho Thanks for looking into this issue! Yes, the lights seem to work perfect.

When I looked into the technical diagnostics menu I noticed normal behavior of the human power both when lights are on and off. Duty cycle drops to 0 when lights are turned on, sometimes toggles a bit between 0 and 1. Duty cycle is working as expected when the lights are off.

It must have something to do with the electrical load? Because when I disconnect the lights wires I do not have this issue. But also no light 😛

[casainho]

If you are driving the bicycle as usual, the duty-cycle should be higher and not 0. If duty-cycle is 0 when the issue happens, we need to understand if for some reason or the motor controller is reseting for some reason or is a bug on firmware.

But for your description, seems something related to hardware.

Look, I think the DC-DC IC that steps down the battery voltage to 6V for lights, protects itself against high temperature - for some reason it may be heating to much, like driving with to much current the lights.

I was looking a lot the original firmware and I can't understand how lights are turn on. But it seems it controls the pin with a PWM signal??
I would suggest for you to drive that pin with PWM and duty-cycle of something like 50 or 25% to see what happens, because lower duty-cycle may mean lower current and less heating to the IC.
You can use the PWM motor interrupt of 64us to count cycles to generate the PWM, just for testing. I would try a frequency of 1khz or lower.

[lightcore-x]

@casainho Thanks! Do you have any information about the current it's able to provide on the lights output? I'm using an e-bike specific headlight which requires a minimum of 4W according to vendor information (=0.8 A). I don't have a light which requires less current available right now.

What I don't understand is that the lights remain on and stable when the DC-DC converter is overheating, if that's the case.

What is also really weird is that I have to stop pedalling before the motor stops assisting when the lights are on. When I turn on the light and keep pedalling there is no issue! As soon as I've stopped pedalling the issue occurs and assistance never comes back until the light is switched off again...

We're you able to measure the PWM signal of the original firmware? I'll try your advice. Thanks again!

[casainho]

See here the datasheets of the motor controller (maybe you or someone could move that information page contents to the wiki): https://opensourceebikefirmware.bitbucket.io/development_tsdz2/About_Tongsheng_TSDZ2_mid_drive_motors--Motor_controller.html

The datasheet of XL7005 says:

• Maximum 0.4A Output Current
• Built in thermal shutdown function

[lightcore-x]

@casainho I think we are driving the enable (EN) pin of the XL7005? Is the enable pin meant to be used with PWM? I don't see this in the datasheet. Are there any relevant components around the XL7005? Is the duty cycle configured this way?

Did you have a chance to measure the PWM signal of the original firmware?

[casainho]

No I can't.

See this datasheet of a pin compatible IC and says the Onoff pin can also be ised for dimming - so yes, I think is possible:

BM0150HV.pdf

https://www.google.pt/url?sa=t&source=web&rct=j&url=http://www.bookly.com/images/BM0150HV.pdf&ved=2ahUKEwj44rnquMDdAhXO-aQKHSwVAaUQFjAVegQIBhAB&usg=AOvVaw2kVAUU2YqkObvYS6Up2UqD

[lightcore-x]

@casainho I've tried your suggestion and I'm very disappointed with the result. The lights ain't working anymore! Even when using the original (working) firmware. It seems that the device can't be driven with PWM and the DC-DC converter is broken now...

Is the epoxy in the motor controller removable? I think so. Then I can replace the DC-DC converter, maybe even with another version.