Hello all,
I am facing a weird issue with PCA9957HN-ARD board.
The board seems to have issues when controlling the LEDs by varying the PWM.
What works well is that if I set IREFALL and PWMALL to maximum (255).
When I change the PWMALL to anything other than 255, the board shows that many LEDs have short circuit. But this isn't the case when IREF and PWM is at max.
I have tried gradation control as well. It is the same result here. When PWMALL is not max, the LEDs show short circuit.
This is the output from my command line when PWMALL and IREFALL are at 255.:
$>
led.ext.writereg 0x6A 255 #PWMALL (At 100%)
$> led.ext.writereg 0x6A 255
[OK]
$>
led.ext.writereg 0x6B 255 #IREFALL
$> led.ext.writereg 0x6B 255
[OK]
$>
led.ext.allerrors
$> led.ext.allerrors
LED[0 ]: No Error
LED[1 ]: No Error
LED[2 ]: No Error
LED[3 ]: No Error
LED[4 ]: No Error
LED[5 ]: No Error
LED[6 ]: No Error
LED[7 ]: No Error
LED[8 ]: No Error
LED[9 ]: No Error
LED[10]: No Error
LED[11]: No Error
LED[12]: No Error
LED[13]: No Error
LED[14]: No Error
LED[15]: No Error
LED[16]: No Error
LED[17]: No Error
LED[18]: No Error
LED[19]: No Error
LED[20]: No Error
LED[21]: No Error
LED[22]: No Error
LED[23]: No Error
[OK]
When I change the PWM all to something less:
$>
led.ext.writereg 0x6A 100 #PWMALL (At40%)
$> led.ext.writereg 0x6A 100
[OK]
$>
led.ext.allerrors
$> led.ext.allerrors
LED[0 ]: Short circuit
LED[1 ]: No Error
LED[2 ]: No Error
LED[3 ]: Short circuit
LED[4 ]: No Error
LED[5 ]: No Error
LED[6 ]: Short circuit
LED[7 ]: No Error
LED[8 ]: No Error
LED[9 ]: Short circuit
LED[10]: No Error
LED[11]: No Error
LED[12]: No Error
LED[13]: No Error
LED[14]: No Error
LED[15]: No Error
LED[16]: No Error
LED[17]: No Error
LED[18]: No Error
LED[19]: No Error
LED[20]: No Error
LED[21]: No Error
LED[22]: Open Circuit
LED[23]: No Error
[OK]
Is this an error on this particular PCB? Or Did somebody else experience this?
Is there something wrong with my approach?
If I can get PWM to work, then I can control the LEDs to represent different colors.
Please suggest something I can try!
Best regards,
Duke
PCA9957 #PCA9957HN-ARD
