Arduino clock and voltage drops

I built this simple clock based on Arduino.
Modular synth clock module DIY ARDUINO, "SM Tik-Tak" - Arduino Project Hub

The Arduino produces a nice 5V Gate. After the 1k resistor on the output, I have 3.5V.
This is enough to trigger my ADSR, SH, etc.

But, in the @analogoutput sequencer I am building, I lose voltage between the Gate In (1V+ on the BACKWARD gate, 0.75V on the FORWARD gate) and the dedicated Arduino pins. Making it 2.45V, which is exactly not enough to get a HIGH value read. Thus, it does not work.
I understand the diode loss (0.7V), and I am still investigating the 1V+ voltage loss.

As there will certainly be other modules with voltage losses, I plan to:

  • remove the output 1k resistors of the clock to have nice 5V at the output
  • put some TL084 to make a buffer for each output

Is this a good way to solve my problem?

Maybe stupid idea, but there are many others output on the arduino. Why not using 4 more dedicated to the LEDs and keep the nice +5V for triggering.

Or, maybe also checking that everything is on the same ground.

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First, no, I would NOT recommend removing the output resistors. They’re there to protect the Arduino if the output gets shorted — which it probably does, briefly, every time you plug or unplug it. Without the resistor you’re shorting the Arduino pin, which will not make it happy.

I can’t understand the measurements you’re reporting. First, if nothing is plugged in, then there will be no voltage drop across the resistor. (Ohm’s law. There’s no current through the resistor, so ΔV = IR = 0 x R = 0.) So if you’re seeing 3.5 V on the output with nothing plugged in then there must be 3.5 V on the Arduino pin.

But that doesn’t make much sense. How are you powering the Arduino? Should be at least 7 V on the VIN pin, which the on board regulator will turn into 5 V, or an externally regulated 5 V on the 5V pin. Either way, the output pin should have 5 V on it unless the Arduino is so loaded down the regulator can’t supply enough current. But all you have is four LEDs with 1k resistors and two 10k pots, and that should cause no problem.

But you could check that by disconnecting the LEDs and see what effect that has. If that’s somehow where the problem is, I can’t see that moving the LED to a different pin will help — you’re still making the same demand on the regulator.

What would help then would be to use a transistor driver for each LED, so the Arduino doesn’t have to supply that current. Or, if you’re using the on board regulator, switching to an external regulator could help.

But again, none of this makes sense to me. Unless your Arduino’s regulator is bad, I suppose. Try a different Arduino?

(BTW and off the subject, in the above picture the jack terminal labeling is incorrect: the one marked “Ring” is in fact Sleeve.)

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The answer was: I am a dumbass x)
I solder the LED after the output resistors. -_-’
The sequencer works nearly perfectly now
Thanks for your time and answers.

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