Hello, I have Arduino Duemilanove Atmega328 at 5V and I want to communicate with the Barometric sensor BMP085/BMP180 that is powered by 1.8 … 3.6V.
I look at dx.com and ebay. All BMP085 (and new BMP180) modules have voltage regulator (662K) from 5V to 3.3V on board.
I read old question at this forum about BMP085 voltage. I find there “Therefore, you could connect them to a 3.3v device, and use external pullup resistors to 3.3v.”.
Two 4k7 resistors are on the board too.
Do I need to use two bidirectional voltage level convertor on I2C?
At this eBay page i found: “At very least, four connections are required (VCC, GND, SDA and SCL) - there is also a voltage regulator on the board, so this device is 5V tolerant (input voltage must be at least 1.8V). In addition, there are pull-up resistors on the SDA and SCL lines.”
Is it possible to connect module (in attachment) directly to 5V supply and 5V I2C to Arduino?
If there is power supply regulator is logical that I2C is 5V compatible too…