Negative Torque Method

[Abasz]

HI, I am really interested in the your project as I am implementing my own DIY Power Meter.

I am trying to work out whether negative torque should be included or not and I saw that you included option to set the method to be used for negative torque. I found different projects on github dealing with this differently (one was including, the other used abs etc.)

Can you please explain why have you decided to default to NTM_ZERO? I am leaning towards including negative torque as when pedaling some of the positive force is used to offset the negative push of the other leg and not really moving the bike so effectively I would expect these to be reducing the power that is utilized by the bike to achieve forward motion.

Thanks for your thought in advance.

[gsoros]

Hi Abasz, Glad you found this project and hopefully it will be of use to you. I think you're absolutely right, the correct way is to include negative values. I don't remember why I chose NTM_ZERO as default (maybe it's kind of a middle ground), but I recall planning to create a way to record any negative torque so I could plot and quantify it for analysis, but never got around to it. I think it would be really helpful to know if and when it happens and how much you could benefit from correcting your pedaling style. Of course a double sided PM would be ideal. I'm sure some advanced commercial PMs have this. Anyway, this is just another one of the many ways one could improve this project, but at this point it serves my needs quite well so I have little motivation to add new features. Good luck with your build and don't hesitate to contact me if you have any ideas or questions, I find the subject fascinating.

[Abasz]

Thanks! The issue is that I dont have a real PWM so I am not able to benchmark it to anything :)

But thanks for the confirmation.