Spindle Speed Control and digital read outt

[mroberts35]

Has anyone attempted this. I would like to add speed control, whether manually or by code but haven't found a solution. I did see a youtube video once where someone did this on an RS-CNC32 however I can't seem to find it again or any instructions on how to do it.

[HTheatre]

Hi mroberts35,

There is an hidden menu on the touch screen of the RS-CNC32. Press the top right corner of the touch screen -- where you can read the status of the RS-CNC32 (ALARM, IDLE, RUN) -- to reveal it. In this menu you can increase/decrease the RPM of the spindle and the feed rate.

Moreover, you can also reveal an hidden screen when you press the top left corner of the touch screen. In this screen you can see all errors messages of GRBL.

See ya

[krj]

I am also trying to control VFD via GRBL. I hooked up a logic analyzer to the Spindle PWM and Spindle DIR pins and I get no signal there. I used default GRBL without customizing, are there any settings which I should enable when compiling GRBL for STM32 to enable Spindle PWM and DIR? Or is my board faulty?

[mstrens]

I am also trying to control VFD via GRBL. I hooked up a logic analyzer to the Spindle PWM and Spindle DIR pins and I get no signal there. I used default GRBL without customizing, are there any settings which I should enable when compiling GRBL for STM32 to enable Spindle PWM and DIR? Or is my board faulty?

The pin PWM on the board is an open collector output. It means that it works like a switch (with a connection to Grnd).
It can be use directly to drive e.g. an optocoupler (the min pin; the positive being connected to Vcc via resistance).
If you want to see a voltage on this pin, you have to add a resistor (e.g. 1K) between the pin PWM and a power source (e.g. the 5V vcc that is on the board)