ColorCNC Colorlight 5A-75E/5A-75B as FPGA controller board

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2 years 10 months ago #289332 by PCW
One option is to use offset mode PWM so 50% = 0V
so you don't need a DIR signal.

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2 years 10 months ago #289334 by TOLP2

One option is to use offset mode PWM so 50% = 0V
so you don't need a DIR signal.
Wouldn't that basically reduce the resolution with 50% as well?

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2 years 10 months ago #289338 by TOLP2
Just released version 1.2.0 to PyPi with support for Raspberry Pi 5!

This release brings furthermore:
  • An updated watchdog module with an enable pin. This enable pin is HIGH as long the watchdog is happy. It will go LOW when the watchdog bites, for example when the communication gets disrupted. This enable pin can be used to control / disable buffers to bring the machine to a safe state. When recompiling a card, modification of the configuration file is required.
  • Several bug-fixes:
    • in the CLI (correct detection of 64-bit RPi);
    • PWM does not generate errors / warning at compilation;
    • pin numbering of HUB75HAT has been corrected (connectors were mirrored);
    • resolved error with GPIO when there are only inputs or outputs defined..
The following user(s) said Thank You: Mecanix

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2 years 10 months ago #289345 by PCW

One option is to use offset mode PWM so 50% = 0V
so you don't need a DIR signal.
Wouldn't that basically reduce the resolution with 50% as well?
 
Yes is does, but a direction pin is hard to use without introducing glitches in the analog output.

What we do with our firmware is add 4 bits of dither  so say at a 80 KHz 11 bit PWM we get
15 effective bits of resolution with the 3 or so KHz bandpass of the PWM filter.

You can also use PDM but it tends to generate non-linearities because of the finite
and asymmetrical switching times of the output devices, Dithered PWM is a compromise
between PWM and PDM
The following user(s) said Thank You: TOLP2

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2 years 10 months ago #289364 by Ehsan_R
Hello
Can I use this firmware and driver for 5A-75E8.2 (version 8.2)?

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2 years 10 months ago - 2 years 10 months ago #289377 by Mecanix

 

oops, wrong thread. misleading. ([delete])
Last edit: 2 years 10 months ago by Mecanix.

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