0
\$\begingroup\$

I am working with 2 OLED displays. Both use the SSD1306 chip which has interchangeable addresses.

One chip looks like this :

enter image description here

This chip has a clear indicator on what to connect to change the I2C address of the chip.

I also received a chip that looks like this:

enter image description here

I've been tinkering with R3 and R4, to no avail. I haven't got the method to change the address of this chip.

Does anyone recognize this type of breakout board and how to change the address of this board?

\$\endgroup\$
2

2 Answers 2

Reset to default
1
\$\begingroup\$

Today I came across the same problem. Using two displays in one application requires different addresses for the displays, but this type of display is hard wired to 0x3C.

By doing some reverse engineering I found a solution.

On the flat wire connector pin 16 from left is the I2C address. You must disconnect this trace from ground and connect it to any 3.3V point via a 4.7kOhm resistor. Once this is done the display will show up as 0x3D.

I did this by cutting off this single trace by using a scalpel. Then scratch the trace on the FPC and solder a 0.1mm wire. Then find the out-pin from the on board voltage regulator (3.3V) and solder one end of a SMD 4.7k to this pin. The other end of the resistor you connect to your wire. That's all.

Warning! Because of the tiny structures this is very delicate work. Only do it if you are experienced in micro soldering. In addition I recommend for doing this job with the help of a microscope or strong magnification lens only.

\$\endgroup\$
1
0
\$\begingroup\$

It seems to responds, after moved the resistor to 0x7A, at address 0x3D (if usually it responds at address 0x3C, 0x3C+1=0x3D).

3r1

\$\endgroup\$
1
  • 1
    \$\begingroup\$ This does not answer the question. In the question, there are two displays, and the question is how to change the address of the bottom display, and you answered how to change the addres of the top display, and 0x7A and 0x3D are just different notations used by different people for the same address. 0x7A divided by 2 is 0x3D, the first is the so-called 8-bit notation which includes the read/write bit, the latter is the so-called 7-bit notation without the read/write bit. \$\endgroup\$
    – Justme
    Commented Aug 23, 2023 at 6:42

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.