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Topic: SSD1306 OLED Display I2C over a longer distance problem (Read 141 times) previous topic - next topic

mh512

Hello

I have an SSD1306 OLED Display (https://www.amazon.co.uk/gp/product/B01MSPCZWZ/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1)

and am using the Adafruit library to display graphics on it.

The display works perfectly when connected to very short cables to the arduino, but when I run SDA and SCL through longer (5m) CAT5 cable the display graphics become jumbled and often a 'noisy' pattern is displayed on the screen?

Is there anything I can do to resolve this? I have previously run older I2C LCD displays over this distance in the same way with no problems at all, it just seems to be the OLED displays that are causing me problems.

Many thanks
Max

david_prentice

The I2C bus is intended for Inter Integrated Circuit connections on a single pcb.
It is unwise (tm) to use 5m cables.  Especially Cat5e.

The SPI bus will probably work over 5m.   Especially with Line Driver chips at each end.

David.

mh512

Thanks, understood, however I find it strange that standard LCD displays work but these OLED displays don't.

david_prentice

The regular PCF8574 backpacks are 100kHz devices.    There is minimal I2C traffic.   e.g. a 16x2 screen is only written when you change the data.
The OLED is likely to redraw the whole screen several times a second.   (and I think the SSD1306 is a 400kHz device)

David.

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