Help me to connect oled SSD1309

Gromovnik

Hello!

I ask for help in setting up Repetier-FW 1.0.4. I have a Ruramps v.1.3, DUE board. I am trying to connect oled SSD1309 to them with the SPI bus. There are no settings for this display in the uiconfig.h file.

Tell me how to configure soft_spi? As I understand it, the display must be turned on in this way. I would be grateful for your help.

Repetier

You then need manual display configuration.

#ifdef U8GLIB_SSD1306_SW_SPI

u8g_InitSPI(&u8g, &u8g_dev_ssd1306_128x64_sw_spi, UI_DISPLAY_D4_PIN, UI_DISPLAY_ENABLE_PIN, UI_DISPLAY_RS_PIN, U8G_PIN_NONE, U8G_PIN_NONE);

#endif

is the crucial part in ui.cpp that initializes display. So you need to define U8GLIB_SSD1306_SW_SPI as display driver and set the defines used correctly. uiconfig.h describes what settings have which meaning so should be doable.

Gromovnik

in the initialization line u8g_InitSP ..... at the end there are two NONE-pins. As I understand it, this is the purpose of the D / C and RESET pins for the display. Do these pin numbers need to be specified in uiconfig.h? in what form do this?

Repetier

No, if there is explicit U8G_PIN_NONE you can not specify it. Hope they are really not required. Otherwise replace it with the value you need. But reset is never set for all displays. 

Gromovnik

During tests of my display on Arduino Nano, I had to forcibly specify a RESET pin in the examples. Without it, the display refuses to work.

Gromovnik

Anyway, I don’t understand something. Here is the code from the example:

U8GLIB_SSD1306_128X64 u8g (4, 5, 6, 7, 8); // SW SPI Com: SCK = 4, MOSI = 5, CS = 6, A0 = 7, RES = 8

I had to add the RES pin to make the display work. This code works.

in the ui.cpp file, I brought the lines to the following form:

#if UI_DISPLAY_TYPE == DISPLAY_U8G
// u8glib
#if defined (U8GLIB_ST7920) || defined (U8GLIB_SSD1306_SW_SPI)
#define UI_SPI_SCK UI_DISPLAY_D4_PIN
#define UI_SPI_MOSI UI_DISPLAY_ENABLE_PIN
#define UI_SPI_CS UI_DISPLAY_RS_PIN
#define UI_SPI_DC UI_DISPLAY_D5_PIN
#endif
.........
#ifndef UI_DISPLAY_RESET_PIN
#define UI_DISPLAY_RESET_PIN UI_DISPLAY_D7_PIN
#endif
.........
#ifdef U8GLIB_SSD1306_SW_SPI
    u8g_InitSPI (& u8g, & u8g_dev_ssd1306_128x64_sw_spi, UI_DISPLAY_D4_PIN, UI_DISPLAY_ENABLE_PIN, UI_DISPLAY_RS_PIN, UI_DISPLAY_D5_PIN, UI_DISPLAY_D7_PIN);
#endif
.........

In the uiconfig.h file, I uncommented:

#define U8GLIB_SSD1306_SW_SPI

The code compiles successfully, but the screen still doesn't work. What am I doing wrong?

Gromovnik

Little by little I begin to understand what the problem is. My display supports 4-ware SPI interface. The ability to make a 3-ware interface is missing, there are no jumpers on the display board. so you need to somehow teach my Repetier to communicate with SSD 1309 on four wires. So far, I have no clarity in the future.

Repetier

Only know 3 wire - MISO/MOSI/SCK - what is the 4th wire for? or is it slave select? But that is already one of the pins.

Gromovnik

in the specification of the SPI protocol, this pin is mentioned (or rather, in the description of displays). It is referred to as Date / Command. Here is what I found: 

• When using the 4-wire SPI connection, Data/Command is an “out of band” signal that tells the controller if you’re sending commands or display data. This line is not a part of SPI and the library controls it with a separate GPIO pin. With 3-wire SPI and I2C, the Data/Command signal is sent “in band”.
• The use of the terms 4-wire and 3-wire SPI are a bit confusing because, in most SPI documentation, the terms are used to describe the regular 4-wire configuration of SPI and a 3-wire mode where the input and output lines, MOSI and MISO, have been combined into a single line called SISO. However, in the context of these OLED controllers, 4-wire means 

Gromovnik

It turned out for me to turn on the display. True, not as I wanted. I had to re-solder the jumpers, pull the RESET to VCC, the ill-fated DC pin to ground, and it worked on the IIC bus. I did not want to, but I have to. The idea was to combine the display and the encoder, a couple of buttons and connect it all with a cable from a single socket. It's a pity.

Repetier

Looking into docs the last 2 parameter in init that were none are a0 and reset. Not sure if a0 would be dc. But glad you figured out at least a solution.

Gromovnik

it turns out that the limitations are imposed by the u8glib ex.h library. Interestingly, is there an opportunity in the future to finalize it? It seems to me that DC = A0. I already got confused ..... But, if this were true, then the display would connect without problems.

Repetier

u8g development is discontinued. Updates are now in u8g2 lib the next version. Our V2 firmware uses the new library already, but configs are only for a few combos working a sit is in early development stage.

Gromovnik

I looked at the firmware development branch of version 2. Among the boards, I found RuRamps4d, the owner of which I am, which is good news. It will be necessary to try to study this development branch. True, there is a lot of obscurity for me.

Repetier

I don't have that board and I haven't added any displays to it, but you can check on radds board how I would do it if you like to play.