The folks at CCRMA are maintaining a nice set of pd objects to send/receive OSC messages over serial connections.

Unfortunately the latest available binaries (pd_OSCserial_externs20070810.tar.gz - linked off the AVR wiki page) don't deal very well with sending messages from Pd to an attached microcontroller. I've written some patches - until they are folded into the source, I'll make them available here.

Source: serialIO.c

Mac OS X (intel) binary: serialIO.pd_darwin

Test patch to exchange messages with Arduino_Osc firmware: arduino_osc_pd_0001.zip

(open arduino_osc.pd)

Test patch to exchange messages with Wiring_Osc firmware: wiring_osc_pd_0002.zip

(open wiring_osc.pd)

Change log:

12/2/08: 0002 - made pins 0 & 1 available, fixed slider ranges to use 10bit

Earlier versions:  wiring_osc_pd_0001.zip

Notes on adding OSCserial objects into a fresh Pd-extended installation:

• Download Pd-extended.app from SOURCE
• Download pd_OSCserial_externs20070810.tar.gz
• Create Pd-extended.app/Contents/Resources/extra/ccrma-osc and extract extern files into directory
• Start Pd-extended. Go to preferences, make sure that ccrma-osc is on the path.

Notes on compiling serialIO from source on OS X:

• Need Apple developer tools
• on non-CCRMA machine, download pd_OSCserial_src20070810.tar.gz and unzip
• in directory serialIO, run ./configure --with-pd-dir=/Applications/Pd-extended.app/Contents/Resources/include/
• edit serialIO/src/Makefile:

  #LDFLAGS =  -bundle -bundle_loader /usr/lib/pd/bin/pd -flat_namespace

  LDFLAGS = -bundle -bundle_loader /Applications/Pd-extended.app/Contents/Resources/bin/pd -flat_namespace

• run make in serialIO

Notes on changes to serialIO.c:

• While incoming OSC messages to serialIO are expected to be wrapped with prefix bytes (0xBE, length) and postfix byte (checksum), outgoing

  messages from Pd to a microcontroller are *not* wrapped, but sent raw.

  This confuses serial OSC parsers on the other end of the connection.

  Patch: modified serialIO_FullPacket() to wrap messages.

• The calls to tcflush(x->x_serfd,TCIOFLUSH); in serialIO_byte() and

  serialIO_float() lead to dropped bytes in outgoing OSC messages - at

  38400 on my Mac, only ~1 in 5 messages made it out unharmed.

  Patch: commented out tcflush(); called tcdrain() at end of

  serialIO_FullPacket(). Note: not sure if this change interferes with

  single-byte or single-float output; needs to be tested (maybe call

  tcdrain() inside _byte() and _float()?).

• Noticed some unexpected post() behavior when calling serialIO_byte()

  with a char variable local to calling function's scope (got

  interpreted as 32-bit value instead of 8-bit); fixed by changing

  signature of function to take unsigned char (huh?).

• Improved debug reporting from printing signed decimal values of

  outgoing bytes to printing both unsigned decimal and hexadecimal

  values.