Hi.
I have a bmp180 with five pins. One is labeled 3.3 and one is labeled VCC. Could someone please tell me if I can connect 3.3 V from the Arduino Uno to the pin labeled 3.3. The remaining pins SDA, SCL, GND are simple to wire.

 

It is likely that the board has a 3V3 regulator and you could feed 5V to the VCC pin and the board would produce the 3.3V that it needs. Do you have a link or a picture of the board.

 

Hi.
I have a bmp180 with five pins. One is labeled 3.3 and one is labeled VCC. Could someone please tell me if I can connect 3.3 V from the Arduino Uno to the pin labeled 3.3. The remaining pins SDA, SCL, GND are simple to wire.

In the future, please include a link to the device. I doubt many know without searching what a bmp180 or what's on the bmp180 breakout board. In that case, they mostly will just pass your question by. Google shows the sparkfun bmp180 breakout board but that clearly isn't your board. To get a good answer, you need to give more information. We're not mind readers.

 

As @AlbertHall said, the 3.3 pin might be output from an on-board 3.3v regulator. Without more info it's impossible to say for sure.

 

I bought the part in Amazon. So I have only a link from there.
https://www.amazon.de/BMP180-Digitale-Luftdruck-Sensor-Arduino/dp/B00N1TSTPA.
Do I understand it write what AlbertHall said. the 3.3 is an output?

 

Now that actually helps. You can see the 3.3 regulator on the board. I'm pretty sure it feeds both the bmp180 and the 3.3V pin but you should continuity check that. You can either ignore the regulator and feed 3.3V externally on the 3.3V pin or feed it 5V on the VCC pin (but not both). Though, some regulators don't like to have 0V on the input with power on the output pin. The safest approach is use 5V on VCC.

 

I saw some information in the Internet where they recommend to connect the 3.3v pin of Arduino and not the 5v to the VCC of the BMP 180. So what do I have to do?

 

Either way will probably work. I think you have enough information to make a decision.

 

Thank you very much.