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Transposed VCC and gnd pins

Posted: 09 Nov 2019, 00:02
by Wayne_H
While 'commissioning' my fuse burner, I tried 2 different displays that I had on hand - both were 0.96", one a yellow/blue and the other a white OLED. The yellow/blue OLED had the 4 pins arranged as per Phil's veroboard layout - GND, Vcc, SCL, SDA - but the white OLED had transposed Vcc and GND pins - ie Vcc, GND, SCL, SDA. The yellow/blue OLED worked but with the expected blank lines. I made a patch lead to swap the GND & Vcc around for the white OLED and it worked perfectly, so it wasn't a case of mis-labeling.
Transposed power pins
Transposed power pins
Has anybody else come across this? All my OLED displays have come via fleabay or Bangood.

Regardless, be warned :shock:

Re: Transposed VCC and gnd pins

Posted: 20 Nov 2019, 02:55
by iflylilplanes
I had a 0.96" OLED arrive today, and the GRD and VCC are reversed, good catch Wayne, I'll be careful when I install. The 1.3" OLED that arrived last week is as Phil's circuit

Re: Transposed VCC and gnd pins

Posted: 20 Nov 2019, 11:18
by Wayne_H
Credit where credit is due - Phil included a picture of this "trap" in his (re)post:
viewtopic.php?f=81&t=783

I 'discovered' it after I made my post :oops:

Re: Transposed VCC and gnd pins

Posted: 20 Nov 2019, 11:31
by Mike_K
And it isn't just with the 0.96" I2C version. I bought these two 1.3" SPI OLED a few years back, at the same time from an eBayer seller (far eastern). They were advertised as 6 pin, but one came 7 pin and neither matched the photo on eBay either. Some of the other pins are jumbled up, not just Vcc and GND. In fact, they don't even agree on how to mark the positive pin, one has Vdd the other Vcc. But they both work OK, which is the main thing.

Since then I buy all my OLED from the same seller on Aliexpress, they always arrive matching the photo and description, so you can buy some a year later and get the same OLED. And they are generally cheaper than eBay too.

OLED1.jpg
Mike