SH1106 I2C Display usage help.

Kraken767

I bought a 1.3" display off amazon and am having trouble getting anything to show on it. I have the QuickStart and the IC driver for the display is the SH1106, but i cant figure out how to send the right commands to get something to show. I've tried sending the device address as write using the simplei2c lib, then a control byte set as last control byte and write to ram, then several bytes filled with a mix of 0xFF and 0x00's. I'm really at a loss even after a couple nights going over and over and over the datasheet. Id really appreciate it if someone could show me how to pick a pixel and make it work. My last test code is below. I did try setting the page address and columns, but honestly i have no idea what the x and y coordinates of say page 3 column 4 line 5 are or how they relate, so i probably did it wrong. The page concept is whats really throwing me off.

i2c bus;  i2c_open(&bus, 9, 8, 0);
  i2c_start(&bus);
  i2c_writeByte(&bus, 0x78);//device address, write
  i2c_writeByte(&bus, 0x40);//control byte, last control byte, ram
  i2c_writeByte(&bus, 0xFF);//data....
  i2c_writeByte(&bus, 0x00);
  i2c_writeByte(&bus, 0xFF);
  i2c_writeByte(&bus, 0x00);
  i2c_writeByte(&bus, 0xFF);
  i2c_stop(&bus);

pause(10000);

Kraken767

ive been looking over and over the datasheet, just when i think i got it, it dont work http://www.displayfuture.com/Display/datasheet/controller/SH1106.pdf
it'd be great if anyone could help me find out what im doing wrong.

my latest test code:

i2c bus;  
  i2c_open(&bus, 9, 8, 0);
  i2c_start(&bus);
  i2c_writeByte(&bus, 0x78);//device adress, write

  //i2c_writeByte(&bus, 0x80);//cont com
  //i2c_writeByte(&bus, 0x40);//set disp line start

  //i2c_writeByte(&bus, 0x80);//cont com
  //i2c_writeByte(&bus, 0xA4);//set disp on

  i2c_writeByte(&bus, 0x80);//cont com
  i2c_writeByte(&bus, 0xB0);//set disp page 0

  i2c_writeByte(&bus, 0x80);//cont com
  i2c_writeByte(&bus, 0x10);//set disp column high 0

  i2c_writeByte(&bus, 0x80);//cont com
  i2c_writeByte(&bus, 0x0);//set disp column low 0 

  i2c_writeByte(&bus, 0x80);//cont com
  i2c_writeByte(&bus, 0xE0);// read write modify start

  i2c_writeByte(&bus, 0xC0);//cont, ram
  i2c_writeByte(&bus, 0xF0);//data....
  
  i2c_writeByte(&bus, 0x0);//last, com
  i2c_writeByte(&bus, 0xEE);// read write modify end
i2c_stop(&bus);

Hal Albach

Try using a 7 bit address. I believe the I2C write function adds bit 0 to the address and will change your 0x78 to 0xF0

 i2c_writeByte(&bus, 0b0111100);         //device adress, write

Kraken767

i ran an i2c scanner with i2c_poll, it gave me back 0x78. also, on the back of my display and in the datasheet it gives me 0x78 as the address

Hal Albach

Does the SH1106 ACK the writes?

Kraken767

Im not sure about the writes, Ive just been using the simplei2c library. As far as I know, i2c_poll looks for an ACK from a device, and im getting one from that.