i2c accelerometer class

SEDur

Hi All,

I have a fun little project that will most probably use the Sparkfun LSM303C accelerometer; but I will have to write a custom class to handle the i2c data for this product.

Before I go to the effort of writing this class, has anyone already made one, and if so would you be willing to share it please?

Otherwise, is there a nice sustainable way to share such a class and others, if people are interested in sharing code?

Cheers

giuliomoro

There is a better-i2c branch where I have done some work to improve our current low-level i2c api and make it easier to write user-space drivers for i2c devices in C++ or even PureData. I hope to finalize it in the next month, but feel free to have a look.
As for sharing, perhaps the best way for now would be to include it as an example in our example library. You would retain credit and would have to be happy with the license terms of our code(see headers of our example files).

SEDur

Sorry I have taken so long to get back to you. I ended up using a photon, OSC and max, because the photon had a library already and I wanted to give the project to someone else to continue with, without giving them my Bela. Once I get the hardware back, I will have another go at moving the library over using your improved i2c branch.

Is using that branch on Bela, as simple as 'zipping' the repo and 'uploading an update patch'?

Thank you!
Simon

giuliomoro

more or less, see https://github.com/BelaPlatform/Bela/wiki/Updating-Bela#getting-the-experimental-release

There is also an even easier (and faster than that) option, if you are on Linux or Mac: get the source code (through the zip archive or git, whatever works for you) and then browse to the Bela/scripts folder and run update_board, type y - enter a couple of times and it's done.

giuliomoro

Did you get the better-i2c branch? See instructions here:

giuliomoro more or less, see https://github.com/BelaPlatform/Bela/wiki/Updating-Bela#getting-the-experimental-release

There is also an even easier (and faster than that) option, if you are on Linux or Mac: get the source code (through the zip archive or git, whatever works for you) and then browse to the Bela/scripts folder and run update_board, type y - enter a couple of times and it's done.

soeren

I'm looking for an i2c class with some very simple examples, and I've ended on this thread after failing to find something else. I'll be using it with an mcp port expander. Is that link you send relevant? Should I update my Bela, and it will have an i2c class ? thanks

giuliomoro

Sorry, I hoped to finalize the new I2c class over the weekend. Didn't happen. If you update your board with the instructions above, you will have a mostly working I2c class.

There is C++ example of I2c communication for the MPR121 sensor in examples/06-Sensors/capacitive-touch/.
This does not use the new I2cRt class, but maintains its own I/O loop in a separate thread/

There is also an example Pd patch, if writing user-space I2c drivers from PureData is your thing! The core/default_libpd_render.cpp is the backend for this Pd-I2c, and exemplifies the use of the I2cRt class in include/I2cRt.h which uses writeRt or readRt to write/read to the I2c bus asynchronously from the audio thread.

ErikNatanael

I'm working on connecting the Adafruit 9-dof breakout board with a FXOS8700 and a FXAS21002 to the bela and I'm currently trying to merge their Arduino library with the I2C_MPR121 example class. When it's working I'll share it!

ErikNatanael

Managed to get this working, I hope it can help someone else (I'm using the I2c class). Currently the render.cpp is sending magnitude values over OSC, but just adapt the render.cpp code to whatever you want to do.
https://github.com/Nathnainiel/Bela-Adafruit_IMU

soeren

I just updated the bela core stuff as you suggested , to the newest, but doing a #include<I2cRt.h> does not work. is this not the name of the i2c class that I should be looking into ?

soeren

aah shoot, i just got the "dev" branch. will try the better-i2c now then, ty.

EDIT: before i get this new core content, I'm trying to get the latest image as well.. just to be updated