Learning to find I2C addresses of sensors for Arduino Due

Question

Hi! My name is Rahim M. and I am a full time Mechanical Engineering student at South Mountain Community College.

I am currently taking a Engineering Special Projects class involving ANSR and ASCEND for a weather balloon experiment.

My classmates and myself have chosen to use the Arduino Due microprocessor for our project because of its immense power and versatility as a processor, but just about everyone on our team is ignorant to the knowledge of how to program with Arduino, especially with I2C addresses.

If anyone out there can give us advice on how to begin finding and programming with I2C addresses for our Arduino Due, it would be very much appreciated.

I understand that finding I2C addresses is a rather complicated task, especially for beginners, but we really need the knowledge of how to do this in a simple manner as soon as possible.

I look forward to hearing from everyone!!!

Thank you.

Rahim M.

Former Member · Answer

Rahim; There are a couple of excellent tutorials on tronixstuff.com specifically about using I2C and Arduino. It looks like you've already been to Adafruit, so no need to mention that. http://tronixstuff.com/2010/10/20/tutorial-arduino-and-the-i2c-bus/ Here is a more general one on SparkFun: https://learn.sparkfun.com/tutorials/i2c And the I2C/Wire library reference on the Arduino site: https://www.arduino.cc/en/Reference/Wire When you're reading, the "Two-Wire" or "TWI" protocol is I2C. Some refer to it as Two-Wire, understandably, as connections just require two wires: SDA (Data) and SCL (Clock). A couple of gotcha's that you may or may not be aware of. The Due is a 3V3 uC, unlike most Arduinos, which are 5VDC. You'll need to reference (Include) the "Wire" library in your programming. If you're using an IDE besides Arduino (Keil, Atmel Studio, etc.) then check Atmel's website for additional libraries required. Arduino pins can sink 20mA of sustained current, or 40mA max. Not a problem using I2C, but if you use other pins be aware of those limitations. Use a 9-12VDC/2A power source on the DC jack, when not using the USB port for power. Any lower voltage and your uC may destabilize. Much higher and the on-board voltage regulator will get too hot. You can't really attach a heatsink as the VR is flush-mounted on the PCB. Best of luck!

shabaz · Answer

Hi Rahim, The Wikipedia page for I2C explains that devices are either master or slave. The microcontroller on the Arduino Due is a master device usually. It doesn't have an I2C address. I2C addressing is for slave devices. The usual method is to see what integrated circuits (ICs) require I2C interfacing, and then the addresses can be found in the product datasheets for those ICs. You can just type the IC part number in google to get the datasheets. Does the Arduino Due have peripheral chips on-board that use I2C? I didn't think that was the case, but I'm not familiar with it. If you're interfacing an I2C device to the Arduino Due, then you need to check the datasheet of the device that you are interfacing.

Learning to find I2C addresses of sensors for Arduino Due

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