[PD] Question about transmission order to serial port [comport] with two independent streams

[Christof Ressi]

When sending data over a serial connection, it's good to have some sort of protocol to distinguish messages. A very common protocol is SLIP https://en.wikipedia.org/wiki/Serial_Line_Internet_Protocol
It's often used for streaming OSC messages (e.g. TCP or serial). You can encode in Pd with [mrpeach/slipenc] and decode on the Arduino with https://github.com/CNMAT/OSC/blob/master/SLIPEncodedSerial.h

On the other hand, MIDI is already a protocol (messages are delimited by status bytes) and you could send your display data on an unused MIDI channel or even as Sysex messages.

Christof

> Gesendet: Sonntag, 14. Juli 2019 um 14:59 Uhr
> Von: "Ingo" <ingo at miamiwave.com>
> An: 'pd-list' <pd-list at iem.at>
> Betreff: [PD] Question about transmission order to serial port [comport] with two independent streams
>
> Hi there,
>
> I need to send both display data and MIDI out data to the same serial port
> via USB using [comport] going to an Arduino Micro.
> The MIDI goes on to the serial transmit pin and the display goes to the I2C
> pins.
> Unfortunately neither the display nor the MIDI data is very predictable
> concerning timing.
>
> The display uses drip to send one character after the other and MIDI is
> sending out manipulated data from the MIDI input whenever MIDI comes in.
> Both senders are on different sections of the software and are not
> synchronized in any way.
>
> Since I need to find a way to split up each stream inside of the Arduino
> without meshing them up and causing errors my question is:
>
> Does Pd send one message (or packed numbers) with two or more values without
> interruption?
> If yes I could simply prepend an unused number (like e.g. 253 or 254)  as a
> header in front of each MIDI Byte.
> If needed another one for the display data.
> (The latter is probably not necessary since I can reset after each MIDI Byte
> inside of the Arduino to keep sending again to the display.)
>
> Meshing up MIDI and display data would be absolutely chaotic!
> If I can't guarantee that each Byte goes to the correct destination I will
> have to use two separate arduinos.
>
> Thanks!
> Ingo
>
>
>
>
>
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