BV4626 shimmer

Hi there

I've got a BV4626 connected by i2c to a BV523. I am able to program it as expected but i am a little disappointed with the PWM outputs of the digital channels.

I purchased the BV4626 in order to dim RGB (+white) LEDs for a lighting project but so far have been unable to produce anything acceptable to the human eye! This is because the output shimmers/flickers when below around 180 decimal output per port.

I have read in the notes that the duty cycle is 8ms which equates to 125Hz - this should be fine for the human eye. It also states that the timings will vary if there is considerable activity on the serial bus. I'm fairly sure that there is no activity since the i2c port is closed and the flicker still occurs.

is there any fix for this? it seems a shame to have to look around for a replacement module when this one does everything i need!

thanks


dan

Dan,
I will have to look into it; the solution may be to put a low value resistor and capacitor on the output:

o/p -----|resistor|---------- LEDS
                       |
                       |
                      Cap
                       |
                      GND

This will act as a low pass filter, start with 50 to 100R and 100uF capacitor.