[SCRAP - do not buy] OLED 0.91 with I2C interface - useful or scrap

[espruino-discuss3]

Posted at 2016-04-07 by @MaBecker

got a 0.91 OLED with i2c interface from china and spend a lot of time without any
success to display some text, just a dark display , grrrrrr !?

this is it: http://www.ebay.de/itm/201537040004

Any hints to get this working ?

used code:

/* esp8266 12E 4MB
1v85.MaBe_master_dc21cae
EMBEDDED=1
USE_NET=1
USE_TELNET=1
USE_GRAPHICS=1
*/

// 0.91 OLED from China via over I2C 4pin GND,VCC(+3v3),SCL,SDA 

// setup I2C stuff
I2C1.setup({sda:D4,scl:D5});

function start(){
 // write some text
 g.drawString("Hello OLED !-!",2,2);
 // write to the screen
 g.flip(); 
}
var g = require("SSD1306").connect(I2C1,start);

no console output

[gfwilliams]

Posted at 2016-04-07 by @gfwilliams

Do you have I2C pullups?

I'd seriously suggest that you try it out first with an Espruino Pico - just to remove the possibility that something (I2C or Graphics) on ESP8266 is broken

Also, look on: http://www.espruino.com/SSD1306

There's specific code there for 32 pixel high displays that you should use. You could also try g.setContrast(number from 0..255) as well

[espruino-discuss3]

Posted at 2016-04-07 by @MaBecker

Do you have I2C pullups?

Yes there are 4.7KΩ pullups for SDA and SCL onboard.

I'd seriously suggest that you try it out first with an Espruino Pico - just to remove the possibility that something (I2C or Graphics) on ESP8266 is broken

This Code and more complex one is working with this OLED from adafruit without any problems, so I2C and Graphics is working excellent on ESPs with 1v85, but yes I will try this too.

Testing with g.setContrast(number from 0..255)and {height:32} did no changes.

Will try to skip this 74LVC1G245 for SDA and SCL because this device is not visible with i2cdetect on beaglebone

Attachments:

• Bildschirmfoto 2016-04-07 um 07.42.32.JPG

[espruino-discuss3]

Posted at 2016-04-07 by Wilberforce

Do you know what the i2c address for the device is? If you scan the i2c bus does it show up?

[gfwilliams]

Posted at 2016-04-07 by @gfwilliams

It could be the device is actually set up in SPI mode rather than I2C?