Persist PWM parameters

Technical Support
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1

Hello Community!

I’ve been struggling for a while with certain issues and I truly hope that someone has stumbled upon some good solution.

I have created a new adapter board for a new display connected to my Colibri iMX6 or T20 module with an Iris Carrier board and Win CE7. However, the backlight brightness control has been inverted on my display. I have found that the backlight is controlled by the PWM duty cycle and I have managed to control it using the PWM_Demo app provided by Toradex. Thus, setting the PWM_A duty cycle really changes the brightness of the display. Since I have inverted logic, I need to have 100% duty cycle by default, when the module is turned on. How can I manage to set the default value of PWM_A duty cycle to 100% on boot? Is there possibly some Registry key to handle this? I want my splash screen during boot up to be visible :slight_smile:

Thank you all in advance! Hope to hear from someone with a good idea soon. Stay safe!

2

This issue can be solved by using the Bootloader Customizer Kit.

3

Hi @Mozart !

Do you have news about this topic?

Were you able to solve it?

Best regards,
Henrique

4

Hi @alex.tx and thank you for your reply.

Quite a late reply, but I hope it will help someone in the community who stumbles upon the same issue. I have managed to solve this issue bit differently so here is my workaround for others who might have a similar issue.

Since the PWM_A uses SOODIM 59 (GPIO41) pin, and in essence, the PWM output should be inverted, using ConfigBlockEditor, in Section Pin I have set the following:

59.ctrl = 1 (to enable configuration of the pin at boot)
59.direction = 1 (as output)
59.level = 1 (high)
59.strenthg = 7 (this parameter controls the brightness of the backlight)

5

Hello @Mozart ,
Thanks a lot for your feedback and additional information :slight_smile:

Best regards,
Josep