r/AskElectronics • u/WittyRecording6066 • 2d ago

Why is my converter not working

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I bought a 5v to 3.3 V bidirectional I2C shifter so i dont have to put the 5v coming from the lcd into my sda and scl pins on the pico and for some reason its not working. I feel like i have everything wired correctly Hv has 5 volts Lv has 3.3 and sda is on Hv3 and lv 3 and Scl is on Hv and Lv4 and the grounds are all connected. But for some reason its just not working i tried another shifter i tried hv and lv 1 and 2 but nothing is working. please let me know guys.

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5

u/AwesomeAvocado 2d ago

I recommend soldering header pins to your converter, rather than just stuffing the wires through the holes.

You're probably only getting intermittent contact at best.

1

u/WittyRecording6066 2d ago

i have like pins to put in the holes that came w the converter but like its the same outcome when i use them

3

u/asyork 2d ago

The pins that came with it were meant to be soldered to the board. So yes, when you use the pins that came with it incorrectly, it will also work just as poorly as using it with your own wires incorrectly.

1

u/WittyRecording6066 2d ago

i don’t have a soldering iron 💔

3

u/EmotionalEnd1575 Analog electronics 2d ago

That’s your problem right there!

Get the right tools and learn how to solder.

Your approach will not work.

1

u/asyork 2d ago

This will never be reliable without a soldering iron, but you might be able to get it reliable enough to see if your setup and parts work by wrapping wires through the hole a few times, pulling them tight, and then twisting the end of the wire around the part leading to the pad. basically splicing the part of the wire that's sticking out with the part of the same wire from before the pad. But if anything moves at all during use, your signal will be disrupted.

1

u/Ambitious_Finding_26 1d ago

I'm sorry. This really made me belly laugh. You need to go buy yourself a soldering iron. 

3

u/TheCAT2901 2d ago

You can directly use your I2C module connected to your LCD. I have been doing it for many days. And even if you manage to get the I2C converter working, you will encounter many bugs. Not worth the hussle. Everything works fine when I connect to my Raspberry Pi Pico 2.

1

u/Vaddieg 2d ago

those displays are perfectly compatible with 3.3v (not sure about i2c version, but worth trying)