i want to use a "IS31FL3731" I2C PWM expander to dim my LED Strip. This expander does have a lot of PWM outputs and i also need a lot of Digital outputs. So is it possible to use a few PWM outputs as Digital outputs? If i think logically, it should work, but i didn't found some stuff in the Internet about it? So, can someone explain me, why it does work or why not? Thanks

  • the IS31FL3731 is a display driver ... it will light LEDs in sequence ... 1 of 144 lit at any one time ... you could connect just some of the LEDs in the 12x12 matrix ... you would have to build a driver for the extra current that the strip requires ... in theory, you could control 144 LED strips
    – jsotola
    Jan 27, 2022 at 18:32
  • It is a display Driver, but i want to use every Output seperately. I planned to take some mosfets to get the extra power to the LED-Strip
    – manintree
    Jan 27, 2022 at 18:37
  • the datasheet says each of the 144 LEDs can be dimmed individually with 8-bit allowing 256 steps of linear dimming ... replacing each LED with a suitable optocoupler may be the simplest approach
    – jsotola
    Jan 27, 2022 at 18:43
  • Ah, I did once use the PCF9685 16 channel pwm controller as GPIO pin expander. What I did was to set the pin to 100% duty cycle, and the pwm pin becomes a 'GPIO" pin. Every thing goes smoothly.
    – tlfong01
    Jan 28, 2022 at 2:32


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