Grovepi+ and pure data


#1

Hi everyone

newbie here, working with an art collective to use bio-monitoring tools to create sound.
We just bought a grovepi+ and some grove sensors :

finger-clip heart rate with shell
GSR
3-axis digital gyro
as well as some “non grove” bare flex and pressure sensors

Now we would like to interface them with pure data (http://puredata.info/) which for those who wouldn’t know is a nice realtime visual programming language widely used for instance in the field of improvised music.

Pure data is cross platform and can be installed on the R-pi.

I think that bringing the possibility to simply access the grove sensors data in pd could also be useful for the communities.

There are a few working options to interface pd and arduino, like pduino or arduino2pd.

http://playground.arduino.cc/Interfacing/PD
http://puredata.info/downloads/pduino
etc.

Do anyone know if I could safely flash the grovepi+ firmware using one of these options and what would be the way to process ?

Or would it be better to write a specific pd external (they are written in c) using the c library provided by dexter industries (this option would obviously exceed my limited technical skills) as described in the following document ?

http://pdstatic.iem.at/externals-HOWTO/

thank you for your attention

s.


#2

Hi fossile,
We had tried using the Grove GSR sensor with the GrovePi but it didn’t work properly. You can read more about the problems here : http://www.dexterindustries.com/topic/grove-heart-rate-sensor-problems/. The 3-axis digital gyro is compatible with the GrovePi but we don;t have the drivers and example written for it yet so you might have to write the example for it. The flex sensors and the pressure sensors should work because they are mostly analog sensors and the GrovePi can read them through the 3 analog ports on it.

I just had a look at the Pure data libraries and I don;t think they’ll work with the GrovePi because they use Serial to communicate whereas the GrovePi uses I2C, so you might have to build your own externally library, which interprets commands from puredata and send them to the Grovepi.

Feel free to ask any questions you have.

-Karan


#3

Hi Karan and thank you very much for your answer.
Unfortunately I am not a programmer and we do not have enough time and skills to dive in the particular issues regarding grovepi and arduino compatibility with pure data as an interface. It was our mistake to give a try to this solution without enough research and I think we’ll rather focus for the ongoing project on more “plug and play”, tested and documented options to make everything work with a plain arduino + baseshield.
However, we’ll stay plugged on this thread in case someone else would be willing to go on this way.


#4

Hi fossile,
Sorry for not being able to support you much on this. For you application, Arduino seems a better choice because puredata supports it and would be easier to use. If you want, you can have a look at Arduberry: http://www.dexterindustries.com/arduberry/ which is an arduino shield for the Raspberry Pi and might be better suited for your use. It give you the ability to use all the interfaces directly from the Pi without any messy wires.

Do let me know if you have any more questions.

-Karan


#5

Hi Karan

we will consider using arduberry. Is it 100% compatible with arduino ? can it alternatively be used standalone without the raspberry pi if needed, or plugged via usb to a x86 computer just like an original arduino ?
thx

fossile


#6

Hey Fossile, you can run it standalone as well. You can not plug it into an x86 computer though, there’s no usb connection. YOu can write and test code on an x86 computer, and then upload to the Pi and run it from there.