U8Glib hw vs sw SPI, my solution

Created Wed, 21 May 2014 08:38:50 +0000 by Nilram

Nilram

Wed, 21 May 2014 08:38:50 +0000

Hi

This is my first post on the forum.

I have a project where the sketch became too big for the Arduino uno R3, so I got an uno32. The sketch compiled fine on the uno32, BUT, my oled display stayed black. I tried different parts of the sketch on their own, everything worked fine apart from the display. The display is a NHD-3.12-25664, 256x64 with ssd1322. I tried uncommenting the different constructors in the sketch, I tried the examples in the u8g library, no luck.

Well not being a wizz on either hardware or software, a thougth struck me anyway; maybe then the pins written in the constructor (13, 11, 10, 9) is hw SPI? I use pin 8 for reset.

In the u8g wiki under supported devices, hw SPI is marked N.A and sw SPI is impl. for ssd1322 NHD-3.12-25664, 256x64, on chipkit. So I tried some other pins (39, 38, 37, 36,35) and BINGO The display is alive again. On a sidenote, if your display is larger than 240x240 pixel, remember to uncomment the line: # define U8G_16BIT 1, in the u8g.h file in the utility folder.

Nilram

Jacob Christ

Fri, 23 May 2014 18:20:36 +0000

There are some jumpers associated with the SPI on the Uno32 as well, maybe these were not set right for the pins you were trying to use.

Jacob