Why can electric bike motors run without being "armed"?


#1

Is it possible to run RC type motors without having to arm them?


#2

They have their own safe guards - my bike wont start up when I flip the power switch on with the throttle engaged.
I was never part of the RC world, maybe they considered motors engaging props more dangerous so an audible warning was needed.

Cheers, Patrick


#3

It really all depends on how the ESC is programmed. All off the shelf ESCs have an arming threshold built in due to safety as @E-pusher mentioned. You usually dont want it to boot up and immediately go to high if the input source is stuck on high.

For the OpenPPG design there are actually 2 factors that keep the motors from spinning when depressing the throttle on start up. The ESC expects a PWM value of 1000 to be initialized in normal mode as you can see in the code here. It can also be set to programming mode by sending a high value etc. so that’s one reason why it needs to be specific.

But before the ESC can even be initialized the throttle controller system is also designed to not arm when the potentiometer is depressed. The throttleSafe() function in the code will return true or false which is used to determine if the ESCs can be safely armed. In the future there will be more inputs, such as verifying that the system is upright, battery temperature is good, your fingerprint has been verified (jk) and more.

Hope this helps clarify the “arming” process of the OpenPPG!


#4

I like the fingerprint idea

STAY AWAY FROM MY OPENPPG :slight_smile: