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IR test messaging — Parallax Forums

IR test messaging

ArchiverArchiver Posts: 46,084
edited 2003-06-26 16:19 in General Discussion
Can the IR buddy send and receive simple text messages from one stamp
user to another across the room?

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-06-25 19:22
    It can be done, but the buffer is only eight bytes and you'll need some
    handshaking. There is a master-slave example in the documentation; it
    can be modified to send text.

    -- Jon Williams
    -- Parallax


    Original Message
    From: pstrittmatter [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=0pw5Jehg1UFX0KpZyOgbMu6T5YEWeFhE5En1fULu3tZ7_JhC7sT3aNVqdZpvm4_nD7AUgoqV4tkrYIifq9yYaRkI]pstrittmatter@y...[/url
    Sent: Wednesday, June 25, 2003 11:51 AM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] IR test messaging


    Can the IR buddy send and receive simple text messages from one stamp
    user to another across the room?


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  • ArchiverArchiver Posts: 46,084
    edited 2003-06-25 19:27
    Yes, the IR buddy can send text messages
    using IR across a room -- at 300 bits/sec.

    The IR-Buddy uses the Phillips 'RC-5' remote
    control handset standard. This allows your
    remote control to send key-presses to your
    TV or Stereo.

    So, the IR-buddy sends a 'key-press' and
    'mode' -- two 8-bit values -- for each key
    pressed on a remote. I havn't done a lab
    yet to find out exactly how fast you can
    send multiple key presses, and have them
    recognized. Note the 'key-press' identifies
    the key you pressed, and the 'mode'
    identifies the device (TV, CD Player,
    Stereo) you are trying to control.

    The IR-buddy also receives these 'key-presses'
    and returns up to 8 bytes ( 4 key-presses,
    since each one is 2 bytes) to the caller.
    It uses the 'SERIN/SEROUT' protocol.

    You are allowed 0..63 for 'command' code
    (the key) and 0..31 for the 'system' code
    (the device). If you limit yourself to
    uppercase ascii, and manipulate the values
    a little, you can fit them into the 64
    values of the 'command' code, and use
    the 'system' code to 'select' a particular
    device (or robot).

    The IRBuddy also can transmit and receive
    arbitrary 8-byte 'packets',
    each value 0..255 -- this would be the
    best mode for text.

    It does take 25 mSec per byte (320 bits/sec).

    Go to the downloads section of Parallax, and
    get the IRBuddy docs.
    http://www.parallax.com/Downloads/Documentation/IR_Buddy_Demo_Kit.pdf


    --- In basicstamps@yahoogroups.com, "pstrittmatter"
    <pstrittmatter@y...> wrote:
    > Can the IR buddy send and receive simple text messages from one
    stamp
    > user to another across the room?
  • ArchiverArchiver Posts: 46,084
    edited 2003-06-25 19:43
    Thank you, that was very helpful. Could the packet transmit recorded
    audio (voice) for playback at the other stamp? If this is not the
    most economical way to send audio data at short range via IR, what
    would you suggest? Also, are there better alternatives using RF?

    Thanks
    Pat

    --- In basicstamps@yahoogroups.com, "Allan Lane" <allan.lane@h...>
    wrote:
    > Yes, the IR buddy can send text messages
    > using IR across a room -- at 300 bits/sec.
    >
    > The IR-Buddy uses the Phillips 'RC-5' remote
    > control handset standard. This allows your
    > remote control to send key-presses to your
    > TV or Stereo.
    >
    > So, the IR-buddy sends a 'key-press' and
    > 'mode' -- two 8-bit values -- for each key
    > pressed on a remote. I havn't done a lab
    > yet to find out exactly how fast you can
    > send multiple key presses, and have them
    > recognized. Note the 'key-press' identifies
    > the key you pressed, and the 'mode'
    > identifies the device (TV, CD Player,
    > Stereo) you are trying to control.
    >
    > The IR-buddy also receives these 'key-presses'
    > and returns up to 8 bytes ( 4 key-presses,
    > since each one is 2 bytes) to the caller.
    > It uses the 'SERIN/SEROUT' protocol.
    >
    > You are allowed 0..63 for 'command' code
    > (the key) and 0..31 for the 'system' code
    > (the device). If you limit yourself to
    > uppercase ascii, and manipulate the values
    > a little, you can fit them into the 64
    > values of the 'command' code, and use
    > the 'system' code to 'select' a particular
    > device (or robot).
    >
    > The IRBuddy also can transmit and receive
    > arbitrary 8-byte 'packets',
    > each value 0..255 -- this would be the
    > best mode for text.
    >
    > It does take 25 mSec per byte (320 bits/sec).
    >
    > Go to the downloads section of Parallax, and
    > get the IRBuddy docs.
    >
    http://www.parallax.com/Downloads/Documentation/IR_Buddy_Demo_Kit.pdf
    >
    >
    > --- In basicstamps@yahoogroups.com, "pstrittmatter"
    > <pstrittmatter@y...> wrote:
    > > Can the IR buddy send and receive simple text messages from one
    > stamp
    > > user to another across the room?
  • ArchiverArchiver Posts: 46,084
    edited 2003-06-26 16:19
    Wow, audio data.
    To make sense of audio, you need to play it back
    at up to 2,000 HZ. This means you need to sample
    it at 4,000 HZ. 300 bits/sec means you can only
    do 'packets' of sound. The BS2 doesn't have that
    much memory on it to store these packets.

    So, to do this, you'll need more external memory,
    or play it back real-time at 150 HZ (which won't
    be legible).

    They do make longer range, higher baud rate RF
    hardware (approx $100 for a transciever) which
    may make this approach more practical. See the
    Parallax RF link, or other posts discussing
    cheaper RF approaches.

    --- In basicstamps@yahoogroups.com, "pstrittmatter"
    <pstrittmatter@y...> wrote:
    > Thank you, that was very helpful. Could the packet transmit
    recorded
    > audio (voice) for playback at the other stamp? If this is not the
    > most economical way to send audio data at short range via IR, what
    > would you suggest? Also, are there better alternatives using RF?
    >
    > Thanks
    > Pat
    >
    > --- In basicstamps@yahoogroups.com, "Allan Lane" <allan.lane@h...>
    > wrote:
    > > Yes, the IR buddy can send text messages
    > > using IR across a room -- at 300 bits/sec.
    > >
    > > The IR-Buddy uses the Phillips 'RC-5' remote
    > > control handset standard. This allows your
    > > remote control to send key-presses to your
    > > TV or Stereo.
    > >
    > > So, the IR-buddy sends a 'key-press' and
    > > 'mode' -- two 8-bit values -- for each key
    > > pressed on a remote. I havn't done a lab
    > > yet to find out exactly how fast you can
    > > send multiple key presses, and have them
    > > recognized. Note the 'key-press' identifies
    > > the key you pressed, and the 'mode'
    > > identifies the device (TV, CD Player,
    > > Stereo) you are trying to control.
    > >
    > > The IR-buddy also receives these 'key-presses'
    > > and returns up to 8 bytes ( 4 key-presses,
    > > since each one is 2 bytes) to the caller.
    > > It uses the 'SERIN/SEROUT' protocol.
    > >
    > > You are allowed 0..63 for 'command' code
    > > (the key) and 0..31 for the 'system' code
    > > (the device). If you limit yourself to
    > > uppercase ascii, and manipulate the values
    > > a little, you can fit them into the 64
    > > values of the 'command' code, and use
    > > the 'system' code to 'select' a particular
    > > device (or robot).
    > >
    > > The IRBuddy also can transmit and receive
    > > arbitrary 8-byte 'packets',
    > > each value 0..255 -- this would be the
    > > best mode for text.
    > >
    > > It does take 25 mSec per byte (320 bits/sec).
    > >
    > > Go to the downloads section of Parallax, and
    > > get the IRBuddy docs.
    > >
    >
    http://www.parallax.com/Downloads/Documentation/IR_Buddy_Demo_Kit.pdf
    > >
    > >
    > > --- In basicstamps@yahoogroups.com, "pstrittmatter"
    > > <pstrittmatter@y...> wrote:
    > > > Can the IR buddy send and receive simple text messages from one
    > > stamp
    > > > user to another across the room?
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