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JFern.5
JFern.5
Associate II
January 26, 2021
Solved

Brightness control in LED1642GW

  • January 26, 2021
  • 1 reply
  • 621 views

Hi everyone,

I've written this little python script to control the brightness in several LED1642GW drivers connected in daisy chain. According to their Application Note, at page 4, it says you have to send 16 words of 16 bits where the first 15 must have a "Brightness data latch" while the last one must have a "Brightness global latch".

My question actually is what those 16 words mean? Does they mean the brightness level? According again to the Application Note... at page 10 the default value of CFG-15 is "0", which means that "16-bit brightness register (65536 grayscale brightness steps)" is selected. So ... I think I should see some brightness variation when I send some different value than 0xFFFF (65535).

The point is that I see always the same brightness level regardless of the value I send. Nevertheless, I have to set the brightness because otherwise LEDs will not turn on when I send the write switch.

What do you think? Am I misunderstanding the protocol to set up the brightness?

Thank you all.

This topic has been closed for replies.
Best answer by JFern.5

Well, my problem was I wasn't feeding the drivers with the PWCLK signal so the comparator (page 12 in the Application Note) could not generate a proper dimming signal.

Anyway thank you all :grinning_face:

1 reply

JFern.5
JFern.5AuthorBest answer
Associate II
February 4, 2021

Well, my problem was I wasn't feeding the drivers with the PWCLK signal so the comparator (page 12 in the Application Note) could not generate a proper dimming signal.

Anyway thank you all :grinning_face:

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