ESP8266 Community Forum

- Sun Aug 16, 2020 6:16 am #88334 Hiya I have recently entered the world of microcontrollers.
I have put together a circuit to turn up and down an LED's brightness with OSC -> PWM and it works well.
Next I added a passive RC filter and had things still working fine. Finally I attempted to step my 0 - 3.3 voltage up to 0 - 5v using a TL072Cp op amp, and I've run into some issues. I'm powering the op amp from the 5v pin but the same issue seems to be present when I use an external 5v supply. Basically the LED remains on and unchanging. I tested the circuit before the op amp and the values seem to be changing fine still with OSC so is something to do with op amp, I tested with another of the same op amp but same issue, here is my badly drawn schematic, if anyone could please help me understand what I'm doing wrong that'd be greatly appreciated!

- Mon Oct 05, 2020 6:18 am #89020

Hiya I have recently entered the world of microcontrollers.
I have put together a circuit to turn up and down an LED's brightness with OSC -> PWM and it works well.
Next I added a passive RC filter and had things still working fine. Finally I attempted to step my 0 - 3.3 voltage up to 0 - 5v using a TL072Cp op amp, and I've run into some issues. I'm powering the op amp from the 5v pin but the same issue seems to be present when I use an external 5v supply. Basically the LED remains on and unchanging. I tested the circuit before the op amp and the values seem to be changing fine still with OSC so is something to do with op amp, I tested with another of the same op amp but same issue, here is my badly drawn schematic, if anyone could please help me understand what I'm doing wrong that'd be greatly appreciated!

Any Update on this OP?

- Tue Oct 06, 2020 3:59 am #89031 Have you tried using a MOSFET instead?

Assumption is the mother of all f*ckups. At least: that's what I'm assuming.