Issue: VESC with Nunchuk works only with full throttle

[RollingGecko]

Hi,

I've now build an Arduino based Nunchuk replacement with nRF24 that communicates with the VESC over UART an takes also the measured values and gives them back to the remote. Currently I use 2812 to indicate for example voltage state. Later I will add a OED. I will soon publish everything.

I just added a small peace of code to the commands.c message handler. I added a message, that sends the nunchuk data and pasts them the the nunchuck app. So far so good. In the bldc tool I can see, that it reads the information of the y-axis fine.

My problem is now, that the motor starts spinning after the deadband with full throttle. There is no regulation possible. I don't think, that it is caused by my implementation. As I sad, on the bldc tool I can see a good interpretation of the y-axis joystick position.

With PWM and direct current setting over UART it works fine.

Any ideas?

Regards

Andreas

 

[benj]

Hi Andreas. Are you using current control? If so, that's what happens. Once you have resistance/a load on the motor the current control takes over. If you've got a board ready to roll then just give it a very cautious test whilst standing on it

 

[vedder]

Nice! I was also planning to add a nunchuk command to the commands interface, but I haven't done it yet. I'm also planning to use the commands interface from the nrf app so that there is no need to add an extra arduino to read data, but I right now I'm working on the FOC implementation so I won't have updates for a while.

Are you sure that there is a problem? The nunchuk app uses current control and if you have no load on the motor it will accelerate to full speed even on very low throttle.

 

[RollingGecko]

Ok. That can be the issue. I didn't try it with load. Just the gear and the roll. But I will !NOT! step on board for first test! Never the less it is still all on a breadboard.

I will try it this evening by holding the roll with my hand (till it get's to hot )

Thx
@vedder: I can send you a pull request of my changes to BLDC. It is not that much. Take a look to it if you want to.


Currently I''m using a library for the nRF24 https://github.com/TMRh20/RF24 where send the measure data back as a acknowledgment message. So I've a reliable connection without any concerns with switching between receive and send. But I already think on a message based version similar to your UART implementation. Because once a display is attached to the remote, there will come also ideas for configuration etc. up.

Any suggestions are welcome. But I will not write a complete library for the nRF. So it schuld be a layer above the https://github.com/TMRh20/RF24.

It would be great to get rid of the arduino on the board site. At beginning I didn't understand anything of the code on the bldc. But now I'm able to adapt also own applications after hours analizing the code to find out how the UART works. I found yesterday the great explanation to the UART on vedders site.

Regards

Andreas

 

[RollingGecko]

OK. First success. I reduced the motormax to 10A. That allows without load a good control. Pushing the c button holds the speed.

But: I'm not able to accelerate or deaccelerate with pushed cruise-control. Why?

And: Reverse does not work. There I will take a look in my code snipped added. Problem is only that I have to wait for a new programmer. I burned mine....don't ask