I2C OLED display - Page 1
Forum section: electronics / projects

author: dan3460
author_rank: Frequent Contributor
timestamp: May 04, 2017, 02:50:28 am
content: I bought a few OLED displays and I started to play with them. The first problem that I encounter is that could not find documentation that relates to this particular board, the Chinese web site only say that uses the SSD1306 so I'm assuming that documentation related to that chip should work with this. So I wanted to play with two of them but I don't seem to find documentation in how to change the address to the boards so I can put them on the same I2C bus.Maybe is in the documentation and I miss it. I have included the picture of the display.

author: ataradov
author_rank: Super Contributor
timestamp: May 04, 2017, 03:01:22 am
content: Go to buydisplay.com. Find this particular display, and it will tell you the pinout. You will find SSD1306 datasheet there as well.SSD1306 supports 2 different addresses on I2C bus. The address is selected via SA0 (D/C) pin. Where this pin is on your panel - I have no idea.Just in case, I'm attaching my driver. It is for 128x32 display with the same controller.

author: theatrus
author_rank: Frequent Contributor
timestamp: May 04, 2017, 05:19:49 am
content: Adafruit also has Arduino libraries and drivers for these displays (128x32 and 128x64, spi or i2c).https://github.com/adafruit/Adafruit_SSD1306All in all it's a simple device to use and dirt cheap.

author: Kilrah
author_rank: Unknown
timestamp: May 04, 2017, 08:12:43 am
content: The pinout of the flat flex should be pretty standard so look at the Adafruit doc which is very complete to see what's where.Most likely the address selection isn't broken out on your Chinese board so you'll have to solder on the strip.

author: Avacee
author_rank: Unknown
timestamp: May 04, 2017, 09:08:55 am
content: One thing to take note of with these displays is that some are 3.3V and some are 5V - and often aren't labelled as to which they are.I know from personal experience the 3.3V ones do not like 5V

author: Kilrah
author_rank: Unknown
timestamp: May 04, 2017, 09:40:33 am
content: I believe alldisplaysare 3.3V - but themodulemay include a regulator/shifter on the board like Adafruit's one (I have one). The cheap Chinese versions are usually simple passive breakouts (like the one above is obviously) so 3.3V only.

author: tablatronix
author_rank: Regular Contributor
timestamp: May 04, 2017, 01:16:18 pm
content: You are looking for SA0 select , pin D/C# on the ssd1306, you have to find out where that is on that particular oleds ribbon cable, I think its pin 15, that one in the middle NC, but i could be totally wrong, I did see a 1325 pinout chart, but not sure if these ribbons are all different pinouts or what.Look around google images for modules with the same ribbon cable as yours, and see if you can trace the jumpers to be sure ( of course most of the ones i saw route to it through vias behind the oled )But that pin seems to have a via on boards with a select i was able to find, and I found a chart that has pinouts for 30 pin oled ribbons, not that they are all the same!https://lh3.googleusercontent.com/88s94JATbuIKf4gN69ZsOBGcfbM0waNvaIb0Hx334AQ=s400http://studio-diy.3dn.ru/_nw/0/16240311.jpg

author: dan3460
author_rank: Frequent Contributor
timestamp: May 05, 2017, 05:41:15 pm
content: Thanks all for the help.

author: tablatronix
author_rank: Regular Contributor
timestamp: May 05, 2017, 08:27:00 pm
content: Let us know if you solve it, but i have a strong feeling pin 15 to v+ will do it.Use one of those i2c scanner sketches to scan.

author: dan3460
author_rank: Frequent Contributor
timestamp: May 05, 2017, 08:29:35 pm
content: I will update the post when I tackle the problem.

author: dan3460
author_rank: Frequent Contributor
timestamp: May 15, 2017, 03:10:23 am
content: I'm ready to tacle the OLED problem. First I checked the address, it is 0x3C. By reading the datasheet and the comments here i'm convinced that pin 15 controls the address to the screen. There are a number of this little screens around, most of them have a address selection link. The problem with the one that I have is that I is connected directly to GND, from that pin I cannot see a trace going out. I suspect that is a via under the ribbon cable or connected directly to a GND plane. I tried to lift the screen to see behind it and a little piece of the glass broke, I think I going to destroy it if I try to find the trace.I will use this screens for another project, I will buy I couple of screen that have the address selection more accessible.