None-smooth transition at low dim value

ESPHome
1

I have an ESP32 NODEmcu that is connected to a MOSFET irlb8721. This all works fine, the problem i’m having is when dimming at at low values (1-5%) is dose not transition smoothly. To exaggerate the problem I put the default_transition_length: 5s during dose 5 seconds it jumps 3 times when it goes from 1-5%. Changing the gamma_correct to a smaller number makes it harder to spot, changing it to a higher number makes it even more obvious.

My guess is that this has something to do with the way ESPhome generates the transition curve (which i understand is done with (this)
static float [smoothed_progress]()(float x) { return x * x * x * (x * (x * 6.0f - 15.0f) + 10.0f); }
and how the gamma_correct is applied.

I would say i understand the high level of why these 2 functions are there but if anyone can point me in the right direction i would be happy to sit and test different numbers to se what works.
My ESPHome config:


light:
  - platform: monochromatic
    name: G34
    id: ledlister_1_G34
    output: G32
    default_transition_length: 1s
    gamma_correct: 2.8
    
      
output:
  - platform: ledc
    pin: GPIO32
    frequency: 19531 Hz
    id: G32
    min_power: 0.5%
    zero_means_zero: true
2

Have you tried a low PWM-frequency yet? It might have to do with none-linearity of charging the gate of Mosfet. Duty-cycle too short to properly open gate. (the Mosfet isn’t a logic-level Mosfet by the way).

3

Thanks for your replay, I did try something like 600hz as well and got the same result.
Ok! I’me quite new to, maybe I should start with a logic-level Mosfet than to see if that helps. Which one would you say is most suited FDP5800 or IRLB3036PBF ? Or are they just competing products from different brands ?

4

Try to ramp up the ‘min_power’ in your output component to like 5 or 10%. Most led strips I had do perform sh!tty at very low power…

5

It will not help your problem. When 600Hz is same.