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I2c mode not working on 1.3" OLED SSD1306 breakout
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I2c mode not working on 1.3" OLED SSD1306 breakout

by mgsb on Thu Jan 07, 2021 2:03 pm

I ordered an OLED display (PID 938) (Order #2390843-7110497487) and believe the I2C mode is defective. I have successfully used it in SPI mode by cutting the jumpers and using the Adafruit SSD1306 Arduino library (IDE 1.8.13 and library 2.4.2) with a Nano. The same board and SW does not respond via I2C. I have tried both I2C addresses and the reset line. Looking with a Saleae probe, both LA and oscope, the signal looks fine but there is only NAK on the I2C bus. A different SSD1306 breakout board works with the same Nano and SW. I have ordered replacements but would like to return this one for credit.

Mark

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Re: I2c mode not working on 1.3" OLED SSD1306 breakout

by adafruit_support_carter on Thu Jan 07, 2021 2:35 pm

The default interface with the new version of the board is I2C. Did you try I2C first before altering for SPI?

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Re: I2c mode not working on 1.3" OLED SSD1306 breakout

by mgsb on Thu Jan 07, 2021 3:10 pm

Yes, I tried I2C with a variety of boards before trying SPI.

Mark

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Re: I2c mode not working on 1.3" OLED SSD1306 breakout

by adafruit_support_carter on Fri Jan 08, 2021 3:27 pm

And did the display originally work when you tried it with I2C?

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Re: I2c mode not working on 1.3" OLED SSD1306 breakout

by mgsb on Fri Jan 08, 2021 4:17 pm

No

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Re: I2c mode not working on 1.3" OLED SSD1306 breakout

by adafruit_support_carter on Fri Jan 08, 2021 4:21 pm

Did you try and troubleshoot why? Or is that what prompted you to move to SPI mode?

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Re: I2c mode not working on 1.3" OLED SSD1306 breakout

by mgsb on Fri Jan 08, 2021 4:44 pm

Yes, I tried multiple MCU boards and SW with I2C mode and never saw even an ACK, so last try was SPI.

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Re: I2c mode not working on 1.3" OLED SSD1306 breakout

by adafruit_support_carter on Fri Jan 08, 2021 4:47 pm

OK, and it sounds like SPI worked, so the hardware is not totally dead. How did you then try to go back to using I2C? Did you solder jumpers on J1 and J2 to re-establish I2C config?

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Re: I2c mode not working on 1.3" OLED SSD1306 breakout

by mgsb on Fri Jan 08, 2021 4:53 pm

Yes

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Re: I2c mode not working on 1.3" OLED SSD1306 breakout

by adafruit_support_carter on Fri Jan 08, 2021 4:57 pm

Please post a photo of the back side of the display showing this solder job.

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Re: I2c mode not working on 1.3" OLED SSD1306 breakout

by mgsb on Mon Jan 11, 2021 11:46 pm

Here's a picture.
Attachments
adafruit_oled_small.jpg
adafruit_oled_small.jpg (91.12 KiB) Viewed 50 times

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Re: I2c mode not working on 1.3" OLED SSD1306 breakout

by adafruit_support_carter on Tue Jan 12, 2021 12:19 pm

Thanks. That should be fine. Really weird behavior. Maybe there's some minor defect on the PCB preventing the detection of I2C mode? Not sure. Let's just replace it.

Send an email to support@adafruit.com with a link to this thread and your order number and they can send you a replacement OLED display.

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Re: I2c mode not working on 1.3" OLED SSD1306 breakout

by mgsb on Tue Jan 12, 2021 5:14 pm

Thanks - I got a new board (from another Adafruit order) yesterday and that board works in I2C mode with the same HW and SW - something is glitched with the original one.

Mark

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Please be positive and constructive with your questions and comments.