Hey Martin,

This is wonderful news.

Will add some more when I have an opportunity to test it out.

Yah!

Julian

On 19 April 2013 14:36, Martin Peach <martin.peach@sympatico.ca> wrote:

Hi Julian,
Yes I've been messing with coding it in c on the pi and sending the data to a [netreceive] in a Pd patch on another machine. I'm attaching the source code for the pi part and the Pd patch.
The code can be compiled on the pi with
gcc -o hello hello.c
You need to set the IP address of the receiving machine in the code (I have 192.168.2.15, it could be 127.0.0.1 for the same machine).
I tried changing the baud rate with
sudo modprobe -r i2c_bcm2708
sudo modprobe i2c)bcn2708 baudrate=90000
but it works fine at the default 100000.
It seems that you only need to write the command once, after that simply reading gets you another packet. Using a combined write/read operation only works half the time, as I also found on the Arduino. All you need to do is write the 0x4C command once, wait a millisecond or so and then read it.
Another issue is that I tried this with the 8X1 sensor, not the 4X4 one, so the code reads 19 bytes (need to change the expected read size in the code). The 4X4 sensor sends 35 bytes which is 3 more than the i2c driver maximum, so you may not get the last part of a packet.
I'll try it later with a 4X4 sensor to see what happens.

Martin

On 2013-04-19 07:01, Julian Brooks wrote:

Hi Martin,

Did you manage to make any progress with the sensor on the Pi?
I also wanted to ask whether the output we're receiving from i2cdump
makes any sense to you as it doesn't to us currently?  Tried searching
around for possible info on the 'XX' & 'ff' but drawing a blank here.

Cheers,

Julian


On 13 April 2013 01:11, Julian Brooks <jbeezez@gmail.com

<mailto:jbeezez@gmail.com>> wrote:

    Hey all,

    Some success finally:

    Hurrah!!

    The scl breakout pin on the pi proto plate wasn't working properly.

    When unscrewed halfway it works, when fully screwed in it doesn't.

    So - now got this:

    i2cdetect -y 0

    0 1 2 3 4 5 6 7 8 9 a b c d e f

    00: -- -- -- -- -- -- -- 0a -- -- -- -- --

    10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

    20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

    30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

    40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

    50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

    60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

    70: -- -- -- -- -- -- -- --

    and

    i2cdump -y 0 0xa
    No size specified (using byte-data access)

    Gives a whole host of stuff I don't yet understand but I don't care
    currently as something is actually happening.

    Will figure out a way of saving the console info (any hints
    anyone?)  as it gets badly mangled when cutting and pasting  but
    basically something like this:

    i2cdump -y 0 0xa
    No size specified (using byte-data access)
          0  1  2  3  4  5  6  7  8  9  a  b  c  d  e
    f                      0123456789abcdef
    00: ff XX XX XX XX XX XX ff XX XX XX XX ff ff ff XX    .XXXXXX.XXXX...X
    10: XX ff XX XX XX XX XX ff XX ff XX ff XX XX ff XX    X.XXXXX.X.X.XX.X
    20: ff XX XX ff XX XX ff XX XX XX XX ff XX XX XX ff    .XX.XX.XXXX.XXX.
    30: XX ff XX ff XX XX XX XX ff ff ff XX XX XX XX XX    X.X.XXXX...XXXXX
    40: XX XX XX ff XX ff XX XX XX 64 XX XX d5 XX XX ff    XXX.X.XXXdXX?XX.
    50: XX ff XX XX XX XX XX XX XX ff XX XX ff XX XX XX    X.XXXXXXX.XX.XXX
    60: ff XX XX XX ff XX XX XX XX XX XX XX XX ff XX XX    .XXX.XXXXXXXX.XX
    70: XX XX XX XX XX XX XX ff XX XX XX XX XX XX XX XX    XXXXXXX.XXXXXXXX
    80: XX ff XX XX ff ff XX XX XX ff XX XX XX XX XX XX    X.XX..XXX.XXXXXX
    90: XX XX ff XX XX ff XX ff XX ff ff XX XX ff ff XX    XX.XX.X.X..XX..X
    a0: XX ff XX XX ff XX XX XX XX XX XX XX XX XX ff XX    X.XX.XXXXXXXXX.X
    b0: XX XX ff XX XX XX ff XX XX ff XX XX XX XX XX XX    XX.XXX.XX.XXXXXX
    c0: XX XX XX XX ff XX XX ff ff XX XX ff ff XX XX XX    XXXX.XX..XX..XXX
    d0: XX XX XX XX XX ff XX ff XX XX XX XX XX ff XX ff    XXXXX.X.XXXXX.X.
    e0: XX XX XX ff XX ff XX XX XX XX XX XX XX XX ff XX    XXX.X.XXXXXXXX.X
    f0: ff XX ff ff XX XX XX XX XX XX XX XX XX XX ff XX    .X..XXXXXXXXXX.X


    Progress at least.

    Cheers,

    Julian







    On 12 April 2013 11:27, Julian Brooks <jbeezez@gmail.com

    <mailto:jbeezez@gmail.com>> wrote:

        Message resent for thread archives with smaller picture size.

        Julian

        ---------- Forwarded message ----------

        From: *Julian Brooks* <jbeezez@gmail.com <mailto:jbeezez@gmail.com>>
        Date: 11 April 2013 19:24
        Subject: Re: [PD] Sensors GPIO Raspberry Pi Pd
        To: Martin Peach <martin.peach@sympatico.ca

        <mailto:martin.peach@sympatico.ca>>
        Cc: PD List <pd-list@iem.at <mailto:pd-list@iem.at>>


        Hey Martin / list,

        Finally got all the stuff and ...

        It’s not working!

        We spent the day soldering cables and connecting stuff up as per
        the Omron ‘App Note 01’ spec sheet.

        Started off super-conservative using the  I2C level converter
        (case 3 page 4) http://www.adafruit.com/products/757#Blog/Flickr

        We tried resistors on both sides (being super paranoid!) and
        then we took  the low (Pi) side ones off.

        We then moved on to case 2 page 3 of this same document…

        At each stage we checked with “I2Cdetect –Y 1” and nothing was
        visible.

        The grid shows no attached devices every time we run it.

        We re-booted at every stage following the various online
        tutorials/methods of setting up I2C GPIO on the Pi (checked &
        double checked).


        As you can see we’re using a pi protoplate:

        https://www.adafruit.com/products/801

        In the photo I’ve attached the cables are coded as follows:

        Orange           GND

        Yellow            5v

        Blue                SCL

        Green             SDA

        The white is also 5v for the pull up resistors.

        The resistor values are 4.7k btw.

        We have tested the cable that terminates at the sensor and all
        that is OK.

        I put a multimeter on the GND and SDA solder points on the
        sensor itself and got 3.7v…

        I put a multimeter on the GND and SCL solder points on the
        sensor itself and got 0.0v…

        Don’t know if this means anything or could be useful to know!

        Stuck and frustrated now but hey, 3 weeks ago I knew absolutely
        bugger all about any of this and now I do (sort of).

        I'm thinking we could do with the most basic i2c sensor we can
        find as we have nothing to compare.

        Tonight I'm going to d/l a fresh raspbian and start from scratch
        to check that end.

        Feel like if we can't get past the 'i2c-tools' tests we're
        screwed - never mind getting it in and out of Pd.

        Any thoughts/pointers/options from anyone will be really
        appreciated?


        Cheers,


        Julian

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