Can you run the same test with the LCD display disconnected? Do you still get noise?
Now I just plugged the signal lines from the high voltage side to the low voltage side. Nothing else changed.
You can see the higher level (around 3.8V) and everything runs like it should.
Well that is to be expected since the inputs are now floating.
Connect the inputs to ground.
No if there is no receiver it will throw an error and stops communication. And then everything looks flat.
Well. Ohhh. A strange effect. Jim we are on the right way!!
I just connected the on side of the encoder to ground and then. Perfect.
Then I do it vice versa. Flatline.
With this:
With this:
With this:
But the encoder itself works well with the „bad setup“. I can control everything.
There may be an error (s) in your code
I think it's time you post it.
Oh my god. Is there a general misunderstanding from my side??
Why do I measure this on a pull-up input?!
That pic of the noise is the LV side, correct? The HV side of that channel has no noise?
There is no noise with the display disconnected? Just flat both sides, correct?
Does the ESP …
If I config a pull-up input I thought it will be pulled-up internally.
What‘s going on here?
No. HS has the same noise. So the shifter works. At least something positive
.
Flatline is because no communication if the display is disconnected. But the same is for the connected display if the controller doesn’t send anything.
I use a library for the LCD and just write some strings each 0.5s.
If you disconnect the display, there is still the same noise on the i2c bus without any transmissions?
The red or the blue?
We need to see the code you are actually using during these tests.
The red
It should be 3.3V for my understanding. Not 0V.
No idea how it ever could work.
I‘m wrong? Do you need to pull it up external??
Then something is wrong in your code or you damaged the nano at some time during all your testing, like applying 5V to a 3.3V pin or both
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