Interfacing two Adafruit MMA8451 via I2C

This week I had to interface two accelerometers (adafruit MMA8451 breakout boards) into one Arduino board.

On Adafruits website, they write that you can address the sensors with 0x1C by adding a pull-down resistor on the “A” pin, or 0x1D by connecting the
“3Vo” to a 3V3 source. What they don’t tell is how to use them both at the same time, which gets clear once you take a look at the Adafruit_MMA8451 class within the library file Adafruit_MMA8451.h.

bool begin(uint8_t addr = MMA8451_DEFAULT_ADDRESS);


Here you have a simple code based on the library example, but adding the two sensors:

Talk nerdy to me! Where I get my electronics updates and news

Ever wondered where is a good place to find new and interesting chips on the market? Questions about electronics and what is happening in the market?

For the engineers and makers out there, the world of electronics can be a bit overwhelmed with so much happening all the time, updates, news and buyouts (specially in the past few months).

I would to use this post to share some of my favorite places to get new chip information, updates and random electronics questions.




Do you remember IRC? Yes, it’s still alive and strong. Just connect to the Freenode network and you will find many very interesting channels where you can talk electronics, exchange information and ask questions! If you are there, drop a line to spillere (me!).

  • #electronics on Freenode
  • #avr on Freenode
  • #arduino on Freenode



  • Fedevel Academy – Learn awesome PCB designing skills
  • /r/nicechips – Reddit, a great place on the internet where people share their findings in the electronic chips market. Really really good!!

This list is still a working in progress. If you have any suggestions please add a comment bellow!