Cannot get 128x64 OLED graphic display to work

I am new to electronics, have bought the Adafruit ESP32-S3 Feather with 4MB Flash 2MB PSRAM and a Monochrome 1.3" 128x64 OLED graphic display and am having trouble getting the screen to work.

The feather board is fine - I have got it running with LED’s and a rotary encoder. The screen is connected via a SparkFun Qwiic Cable to the left hand STEMMA QT / Qwiic connector. The green LED is on, so it has power. The Adafruit SSD1306 and Gfx libraries are installed and I have tried using the Adafruit ssd1306_128x64_i2c example sketch.

The screen remains blank. I tried connecting a damaged screen and it displayed snow - but at least there was something on the screen.

Is there something I am missing? Thanks for any help.

Hey Rob,

Sounds like you have taken a few good troubleshooting steps. A couple of things to make sure of are that the connector is properly seated as even if its only a tiny bit out, it will cause issues and may not work. Other things that you may need to check are if the i2C address is properly configured in your code for the specific device you are using, as this is a pretty common problem when dealing with i2C devices.

otherwise if you could share with us a few pictures of how you have it all set up, that may help us with figuring out some potential issues.

Cheers,
Blayden

Thanks Blayden,
I have checked the connections and they seem to be tight and fully seated. The example sketch has the same i2C address as printed on the back of the screen, I found an i2C scanner sketch which showed this result:
I2C Scanner
Scanning…
I2C device found at address 0x36 !
I2C device found at address 0x3D !
done
I also took some photos to show the setup. I need to practice my soldering!




Thanks
Rob

I now have the screen working! It took connecting the cable to each of the plugs on the screen and trying both 12C addresses. It started to work. Maybe the cable took a few goes to fit properly?

Now it seems to work plugged into either socket using the 0x3D address.

Thanks for the help.
Rob

Hi Rob
Looking at this thread with interest. Things don’t fix themselves. There is something wrong which will probably pop up later.

The first thing that comes to mind is that 4 wire cable. Did it come twisted or did you do that to make it look tidier. If you did that then there could be a possible problem. When twisting cabled like that the connectors are put on AFTER the cable is twisted. When twisting the wires will change RELATIVE lengths and at the end the wires will have different lengths RELATIVE to each other. When twisted AFTER connector fitting several things can happen.
The shorter wires will break, possibly making intermittent contact.
The shorter wires can pull partially or fully out of the crimp pin. Also making intermittent contact.
The shorter wires can actually pull the connector pin/socket partially out of the connector housing making possible intermittent contact with the mating pin/socket in the board connector.
The solution… Bin this cable as it could be forever suspect and use a new non twisted one.
OR Start from scratch a n twist up a cable first THEN fit the connectors.
If a pin/socket has been partly pulled out from the connector body the body will be permanently damaged and will be trouble forever so should be discarded.
Cheers Bob
EDIT. Oh by the way. You are correct, you DO need some soldering practice.

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