[sysex] is used for MIDI messaging and OSC is designed around network-based communication, hence the ethernet shield.What I think you want is simple serial communication which is essentially sending / reading raw byte values. I would look into something like http://playground.arduino.cc/Code/CmdMessenger.The basic idea is similar to OSC, a protocol which determines which bytes are what and how to read them back correctly on the other end. I’m sure you could implement the CmdMessanger protocol in Pd using the [list toSymbol], [list fromSymbol], [oscparse], & [oscformat] object, or roll your own.On Jun 1, 2016, at 8:29 AM, pd-list-request@lists.iem.at wrote:From: Rick Snow <ricksnow@gmail.com>Subject: [PD] Pduino sysex vs. OSC adviceDate: June 1, 2016 at 8:29:16 AM MDTHello list!I am looking for some advice on sending messages from PD to an Arduino sketch. Essentially, I plan to connect a mac to an Arduino via USB and control a large amount of variables within the Arduino sketch from PD.Is using the sysex message with the [arduino] object message the way to go with this? How can I "tag" the messages so that they go to the correct variable in the arduino sketch? Is there a practical limit to the speed of such a system?I am much more familiar with using OSC messaging between applications but when I looked into using OSC with Arduino it seemed like I needed to use an ethernet shield (instead of connect via usb) and I would rather not go that route unless absolutely necessary.Any advice is much appreciated!cheers,Rick