What do you think I2C address on this OLED is?
Is it 0x78?
Is it 0x7B?
Maybe it is 0x7A?
Wrong, wrong, wrong, wrong, wrong!
It is 0xBC!
Is it 0x78?
Is it 0x7B?
Maybe it is 0x7A?
Wrong, wrong, wrong, wrong, wrong!
It is 0xBC!
I don't know, but an I2C scanner will tell you
I just did from 0 to FF, if(.begin(address)) success!!
And the answer was?
I see, you updated your initial post.
Maybe that address belongs to another device on your unnamed MCU board. If you remove the display, do you still get 0xBC?
1 Like
Germany?
My guess the printed address on the display is 0x7B (or 0x78????)
Can it be, by any chance 0x3C ?
"IIC default address is 0x78 (0x3C in 7 -bit) and can be changed to 0x7A (0x3D in 7 -bit)".
2 Likes
Nah, definitely 0xBC as it works with 0xBC and Arduino Nano Every
Amusingly, 3C in 7bit, moved to an 8-bit byte with the highest bit set instead of cleared, would be BC.
So you may all be different flavours of correct, and this could go on all night.
2 Likes
@killzone_kid Could you try 0x3C in your sketch ?
The first byte on the I2C bus is a byte with the I2C address and the Read/Write bit. The last bit is for the Read/Write bit. There are only 7 bits left for the I2C address.
Arduino uses the 7-bits shifted I2C address from 0 up to 127.
That means that I2C address 0xBC does not exist. The Wire library combines it with the Read/Write bit, so the highest bit is dropped. Therefor your 0xBC is the same as 0x3C and 0x3C is a normal I2C address for a OLED display.
You will not find a I2C Scanner that scans up to 255, because there are only 128 possible addresses.
theoretically 128, but only 110 should be used as some are reserved for special purpose:
https://www.i2c-bus.org/addressing/
yes, 0x3c works too
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.