LitexCNC: firmware and driver for 5A-75B and 5A-75E

I'm afraid that the inverted PWM output is not supported yet, without doing some tricks. I think I will make an issue for this and add it to the firmware and driver.

Two possibilities:

• inverting the output when compiling the firmware. Easiest to implement, however not very flexible
• inverting the output using a HAL parameter, similar to GPIO which can also be inverted from the HAL. One can choose to:
  • either invert the duty-cycle (thus a duty-cycle of 5% will be send out as 95%, which is effectively the same as inversing the signal, however the start of the signal shifts) NOTE: this is the trick to 'invert' the signal in the current situation, by choosing scale and offset smart;
  • send an extra WORD to the FPGA with the config of the PWM. This case, the start of the PWM (and thus the frequency)  is always fixed.

If you have preferences, please let me know.

For me both are ok.
But then please explain the Trick image missing /media/kunena/emoticons/smile.png
I did not get it to work and therefore I changed Firmware.

I made an issue / feature request on my GitHub for this:
github.com/Peter-van-Tol/LiteX-CNC/issues/76

I have chosen to add the extra WORD and add the param invert-output to the PWM modules.

@deroj: are you willing to test this branch?

The following steps can be taken to test the changes to LitexCNC:
Re-install the driver and recompile the firmware:
And try the new parameter invert-output for the PWM modules.
 

I really would like to test it, but I am back home in two weeks... image missing /media/kunena/emoticons/wassat.png

h
How can flash the firmware to 5A-75E?

litexcnc flash_firmware <filename-with-extension-svf>
How to create <filename-with-extension-svf> file?
Do I have to download it from somewhere?