Problem with OLED module in i2c mode

I have this module and can not switch to i2c mode, in spi mode it works correctly.

I can not find any instructions tangent to this type of module.

I connect to arduino nano according to the scheme(i used jumper s1 in the module to change the mode i2c/spi)

D0-A5
D1-A4

For tests I used i used test cases, scanners i2c, etc

(photo of the module in the attachment)

Thank you.

11-400x337.jpg

1-400x433.jpg

I suspect that it does not ACK like a proper I2C device. Note that you will not be able to use multiple I2C devices or regular Wire.h

Choose a no_ack constructor. U8g2 certainly has one.

David.

Agree with david_prentice.

This can be solved however.
Check to see pins 19 and 20 of the ribbon cable between glass and PCB, are connected to each other in case you want to do 2 way I2C.

As a matter of fact, i know they aren’t because this is visible in your pictures.

a073a09dc6359407d306a5999a2737f4c12e29a3.jpg

In this picture, R4 is unpopulated.
It needs to be unpopulated in case of SPI mode.
If you follow the tracks , you’ll see that this connects to pins 19 and 20 of that cable.
So put a drop of solder on that R4 position, and you’ll have 2 way communication, which will enable the module to answer to the “ping” being sent by the I2C scanner.

Usually initialisation requires an answer from the controller (which is inside the glass) too, if i remember correctly.
And you will not receive that in case I2C is not set in the correct way.

Olli Kraus’ u8glib can be set to not wait for an answer upon reset if i remember correct.
I’ll be using that library when playing with these displays in future.