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128x32 I2C OLEDs display random patterns of dots
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128x32 I2C OLEDs display random patterns of dots

by recookdotcom on Sun Feb 04, 2018 7:27 pm

Order Number : 1643149-5336464253

The order included 2 of “Monochrome 128x32 I2C OLED graphic display, Product ID: 931”. Both OLEDs display random dots in no discernible pattern (via I2C), as appears in the photo of the complete setup. The third OLED ordered, “Monochrome 0.96" 128x64 OLED graphic display, Product ID: 326”, seems to be working fine via SPI. I have not tried to drive it via I2C.

OLED128x32-Uno.jpg
The random dots are clear in this photo.
OLED128x32-Uno.jpg (91.2 KiB) Viewed 168 times


I tested the 2 128x32 OLEDs with the Adafruit demo sketch ssd1306_128x32_i2c on an Arduino Uno R3. During the scroll section of the demo sketch, both seem to scroll properly, with the random dots maintaining their pattern as they scroll. But other than the scrolling, nothing displayed seems to relate to the sketch. (I tested the working OLED with the sketch ssd1306_128x64_spi, on the same Arduino Uno. The scripts are the examples included with Adafruit_SSD1360.) Note that no software errors are generated. The scripts compile and upload to the Arduino with no problems.

OLED128x32-Headers.jpg
I see no issues with the soldering on the headers. I generally do not have issues soldering headers.
OLED128x32-Headers.jpg (83.29 KiB) Viewed 168 times


Any help or advice will be appreciated.
Richard

recookdotcom
 
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Re: 128x32 I2C OLEDs display random patterns of dots

by adafruit_support_carter on Mon Feb 05, 2018 2:44 pm

Try restaging everything on the breadboard so it's a little cleaner - remove green wire and attach GND directly, move display closer to UNO so wires aren't as stretched. Also, hook up the RST pin to digital 4 :
https://learn.adafruit.com/monochrome-o ... 2-i2c-oled

And then try again.

Also, can't tell for sure - are you powering from 5V or 3.3V?

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Re: 128x32 I2C OLEDs display random patterns of dots

by recookdotcom on Mon Feb 12, 2018 8:56 pm

Interesting... I finally had a chance to redo this, so I started from scratch, same OLEDs but new jumpers, a different breadboard, even a different battery. To my great embarrassment the new setup worked. Turns out I had one faulty jumper in the original. Of course both OLEDs seemed to fail, the wiring was the same for both. Guess I have to be way more careful before posting a request. I should have tested those things first.

Thanks for your help! I'll be more careful next time. :-) (and feeling a little sheepish...)

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