Recent content by magic-smoke

  1. M

    Possible to control resistance using microcontroller?

    @Harald Kapp, thanks for the suggestion but I did also say "...without using a dedicated digital potentiometer." I don't have a digital potentiometer and I'd like to make this with more 'standard' basic (and also cheap) components.
  2. M

    Possible to control resistance using microcontroller?

    Hi @bertus. I tried a circuit similar to the one you suggested, and it's working great. I used a NPN since I have so many, and I didn't use the 10K resister. I'm not sure why that's there? Would you mind explaining why the 10K? And does this circuit (this is what I actually built) have any...
  3. M

    Possible to control resistance using microcontroller?

    @bertus Amazing. Thank you. I'll try it out.
  4. M

    Possible to control resistance using microcontroller?

    Hi @bertus, Thanks for the reply. Could you clarify where the transistor goes? Would it go between the LED driver's power and ISET pins? Or would it go between the circuit's VCC and the driver's V+?
  5. M

    Possible to control resistance using microcontroller?

    I'm using an ESP32. The microcontroller isn't connected to the LEDs directly, the connections are all via the LED driver which gives a more even lighting of the segments and a simpler interface than I could achieve without it. I am reading resistance from an LDR to decide a desired brightness...
  6. M

    Possible to control resistance using microcontroller?

    My project is a clock with 4 7-segment leds controlled by MAX7219 led driver IC. I want to adjust the brightness of the display. There are 2 ways to adjust the brightness. First, I can control it in software - I can programmatically choose one of 16 levels of brightness by sending a value to the...
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