orange pi i96 and bme280 problem

Hi, I’ll make a copy of the topic from the official forum orangepi, can they help me here?
I’m trying to install the bme280 module on the orange pi i96 board.

VCC -> 3.3 (35 pin)
GND -> GND (40 pin)
SCL -> SCL3 (19 pin)
SDA -> SDA3 (21 pin)

According to this pinout

I am doing an i2cdetect check

And nothing works.

Please help solve this problem.

@SH86 I believe that the I/O line voltage is 1.8v. So you would need to do level shifting on SDA/SCL pins to make it to work.

@Mani: That sensor identifies as having “typical” supply and I/O voltage of 1.8 (supply recommended range 1.71-3.6, I/O range 1.2-3.6), and the board should work with 1.8 – there are no level shifters or voltage regulators on it. Just 4 resistors, 10k pullup to SDA, SCL, CSB, and pulldown to SDO.

@SH86: According to documentation, pin 35 is 1.8v, which is what you want to give that board. If for some reason it is actually making 3.3v, then it isn’t going to work because your logic levels are not going to match up. In this case, you will need to find some way to set pin 35 to 1.8v, or put a regulator on it. You should probably test the voltage that is actually on this pin.

Your wiring looks correct assuming that it is actually making 1.8v. If you have access to a logic probe, you should see what is actually going on on the pins. Have you had any other i2c devices working on that orange i96? Have you tested that sensor on a different microcontroller or SBC? I’ve found that the quality control from the vendors that sell those little purple boards is extremely lax. I’ve had boxes of BME280’s show up as BMP280’s (all refunded), I’ve had them show up with the metal cover missing, I’ve had them DOA, and I’ve had them even work intermittently.

You might also want to try plugging it into the other i2c port at pin 15/17 to see if there is a difference in configuration. The other thing you might want to do, is check what speed the i2c is set at on the orange i96. The higher the speed, the more exact the pullup/down on the SDA/SCL lines has to be. Try bringing it down to 100 kHz if it is currently any higher than that.

Also in the future, copy/paste the text, please do not use pictures.