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grblHAL / Plugins_spindle

grblHAL plugins for spindle control
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Spindle RPM override not taking effect. #8

Open andrewmarles opened 2 years ago

andrewmarles commented 2 years ago

Apologies, I can only test this with my vfd_support branch modifications and my GS20 VFD , but I just wanted to report my experiences with the new spindle switching feature.

https://github.com/Expatria-Technologies/Plugins_spindle

The switching works as expected, both with the M code and with the startup spindle setting. And when the device is idle or in hold, I can use the spindle speed override and it works as expected. However, if we are in a run state it seems the spindle override is not taking effect. I will try to get some better insights into what could be going on.

Thanks as always for these cool new features.

terjeio commented 2 years ago

Spindle override works for me when in run state. Tested with a STM32F446 Nucleo board and my CNC machine simulator.

andrewmarles commented 2 years ago

I have continued to chase this down, and it looks to me like what is happening is that the spindle RPM is being polled at a very high rate. I can see this activity on the modbus port. Perhaps this is saturating the modbus buffer and preventing the non-blocking updateRPM messages that are used during RUN mode from being transmitted to the VFD? I have added a timing check on the modbus_send() in the SpindleGetState function that I am using and this does 'fix' the issue in that I can now successfully adjust the spindle speed during a run state.

https://github.com/Expatria-Technologies/Plugins_spindle/blob/ac40ee2937c8e07eb4c85ec5d018723fa0e76ff3/MODVFD.c#L171

But I am not sure this is the best solution to this particular issue? Is there a better place where we can modulate the rate of spindle RPM requests?