SPI and MOSI pins query

Other Hardware Displays
1

I have a sketch which is written for an SPI OLED display. The 2.2" OLED display I have bought has the following pins:

Serial Peripheral Interface Pins:

1.GND(Power Supply Ground)
2.VCC(Power Supply Positive)
3.SCL(Clock Line)
4.SDA(Data Line)
5.RES(Reset Line)
6.DC(Data/Command)
7.CS(Chip Select)

On the circuit diagram for the hardware, it shows DC, CLK, CS, Reset and MOSI. Is MOSI a data lne, the same as the SDA pin please?

Will this display connect directly to the Arduino or is there anything else I should know?

Once verified working, I would like to convert the sketch to I2C, should that present any great difficulty?

2

Life is much easier if you just post a link to your display. e.g. the Ebay sale page.

I have never seen a 2.2 inch OLED.

David.

3

Here it is:

https://www.ebay.co.uk/itm/2-42-inch-OLED-Display-SSD1309-128x64-SPI-IIC-Serial-Port-For-Arduino-C51-SY-YR/173904782034?ssPageName=STRK%3AMEBIDX%3AIT&var=472651931118&_trksid=p2057872.m2749.l2649

I haven't seen it yet, it is a fortnight overdue!

4

Thanks for the link. Copy-pasting the link is a lot easier than typing by hand.

Ah-ha. 2.42 inch !!

Yes, it appears to have a 3.3V regulator on the pcb. So you can connect VCC to 5.0V.

You can probably drive the signals with 5V logic. I would be happier with 3.3V logic e.g. Zero, Due, STM32, ...

Connect SDA to MOSI pin on your Arduino.

U8G2 library has almost certainly got a constructor for this display.

David.

5

Thanks David. I hadn't considered the 3.3V situation. Maybe I will move to something else from my Nano board. I could use a Teensy 4.0 , but I suspect they are not supported here! :slight_smile:

6

Hi David,

also seen here: Digital LCD Screen 12864 128X64 OLED Display Module C51 Board For Arduino White SSD1309 STM32 Diy Electronic 2.42" 2.42 inch

Jean-Marc

7

I am sure that U8g2 will run on Teensy 4.0

I suspect that SSD1309 is "safe" with 5V logic providing it has 3.3V power.
Other Solomon chips seem to be input voltage tolerant.

But since the display is expensive, I would try with 3.3V logic first.
Oliver will probably have an accurate answer.

David.

8

@Jean-Marc,

Similar screen. Different pcb. Bad reviews (but they might just be using the wrong libraries)