China board for PWM Commutation???

Idea i know it maybe a far shot and i know youll say dude read up on the manuals.
Ill admit im excited and havent read enough just started tinkering. You can imagine a guy working years on fanuc paying big bucks on simple equipment and realizing theres another alternative with more options and flexibility. Just alot of more work which pays off in the end.

Ok so i have that red board that i started on the other forum. Since its a stepper it pulses direction and step. Now i got 9 pins that i might be able to use for servos 3 pwm for a bldc? I dont think it will be pretty i dont know if its just high low states can accomplish a true sinusoidal signal.

Does the interface board amplifies port signals or is it serial commands which are then processed on the firmware of the board to pwm?

Just throwing it out there. Im low on cash for my personal project i just want to see what i can accomplish with things laying around on the shop. Lots of fanuc servo motors big and small spindles, inverters and other toys which i have access to. Talked to pico yesterdat and it just started more flow of ideas.

cyrut2 wrote: Ok so i have that red board that i started on the other forum. Since its a stepper it pulses direction and step. Now i got 9 pins that i might be able to use for servos 3 pwm for a bldc? I dont think it will be pretty i dont know if its just high low states can accomplish a true sinusoidal signal.

There isn't a software 3-phase PWM generator, and using three separate PWM generators might not work correctly for your amps.
The issue is dead-time to avoid shoot-through.
The three-phase PWM signal from the Mesa FPGA code is kept in strict phase, and has a programmable dead-time too. There is not currently an equivalent software PWM with the same feature.

However, if the drives themselves ensure shoot-through prevention, then it can be made to work as shown in This Video

This uses the "bldc" HAL component:
linuxcnc.org/docs/2.7/html/man/man9/bldc.9.html

Does the interface board amplifies port signals or is it serial commands which are then processed on the firmware of the board to pwm?.

That depends in the interface board. Many just buffer the parallel port signal, but both Pico and Mesa offer boards that use the paralel port as a communications bus to an on-board FPGA signal generator.