i2c examples?

The_Idiot

Does anyone have a well commented i2c example? I don't really follow the example on the site

jeremydouglass

Do you mean this example?

• https://processing.org/reference/libraries/io/I2C.html

What about it don't you understand -- or what are you trying to do that it doesn't demonstrate?

The_Idiot

Thank you for your response. I don't fully understand the arguments - especially:

i2c = new I2C(I2C.list()[0]);

I am trying to get processing to read in an array of 9 bytes (processing will be running on a pi). I should point out that I'm a beginner when it comes to both processing and i2c. And the pi for that matter!

gohai

@The_Idiot Let me try to answer this: a system might have more than one I2C interface - there is thus a list() method to retrieve an array of available interface names.

Try:

printArray(I2C.list());

To start communicating with a "slave" device connected to any of those I2C busses, you construct a new I2C object by passing the interface name to it's constructor like e.g.:

i2c = new I2C("i2c-2");

And the snippet you posted will simply attempt to use the first I2C interface found...

The_Idiot

That makes sense, seems obvious now! Thank you!!

pbp

Hello, I have written some code to implement functionalities for the I2C devices in the Sense HAT. You can find them here: https://github.com/PBernalPolo/RPiModules

I thought it might be interesting for someone looking for examples of I2C communication.

kfrajer

@pbp Thxs for sharing.

Kf

gohai

That's awesome @pbp. Thank's a lot. I'll give this a shot in a couple days and will send pull-requests if anything catches my mind.

SiriusCG

Thank you @pbp. Very timely! I've been messing about with I2C and your examples clarified a number of points for me. Who knows. Maybe I'll brave the humidity and pressure sensors too. Kudos. :)