ofxSerial problem on Raspberry Pi 4 Buster Lite

arm
#1

Hi there,

I’ve been coding an installation for which I have a Teensy 4.0 (arduino-like thing) hooked up through FTDI drivers to a RaspBerry Pi 4 USB2 port. Because I already had some problems with the ofSerial class I decided to switch the communication to ofxSerial. Now all is fine when I just constant stings, but I need to ‘create’ the string dynamically as I’m sending over different pixel data. When I do this, my functions stop working. They might send a couple times, but after that communication is just halted. I feel like I’m looking over something…

Function that constructs the message;

void Comm::sendPixel(ofx::IO::SerialDevice& serial, int socket_index, std::shared_ptr<Pixel> pixel, unsigned int channel_idx) {
    std::string message = "I,PC," + std::to_string(pixel->index);
    sendPackage(serial, socket_index, message);
}

Sending function;

void Comm::sendPackage(ofx::IO::SerialDevice& serial, int socket_index, std::string message) {
    std::string msg = message;
    std::string idx = std::to_string(socket_index);
    ofx::IO::ByteBuffer socketBuffer(idx);
    ofx::IO::ByteBuffer messageBuffer(message);

    if (serial.isOpen()) {
        serial.writeByte(startMarker_);
        serial.writeBytes(socketBuffer);
        serial.writeByte(',');
        serial.writeBytes(messageBuffer);
        serial.writeByte(endMarker_);
        serial.writeByte('\n');
        serial.flush();
        serial.flushInput();
        serial.flushOutput();
    }
}

Currently I’m flushing everything as I was hopelessly trying to debug the thing the whole day. I detect begin & ends of messages by using beginmarker and endmarkers (’<’ and ‘>’) so the ‘\n’ isnt needed but gives some extra safety.

The use of ofxSerial here is based on the example at; https://github.com/bakercp/ofxSerial/blob/master/examples/basic/echo/src/ofApp.cpp

Any recommendations? I really feel like it has to do with the string that is constructed. Basically tried everything else.

#2

Maybe send the message to the Teensy and have it send whatever it recieves back to the OF app. Then you can see if it gets any thing.