I’ve recently installed PlatformIO on my Raspberry PI 3 which I’m using to compile my program onto my Arduino Nano (Atmega328). The build routine runs just fine, but when I tried to access the Serial port via termios on my Raspi it doesn’t recieve data anymore. After a reboot everything just works fine again and when I use the CLI from Arduino itself it works just fine as well (but it’s terribly slow to compile 
). So it seems that the platformio run -t upload command doesn’t close the Serial stream after uploading… The strange thing is however, that the platformio monitor just works fine after a build. The code I’m using consists mainly of these parts:
On the Arduino
#include "RSerial.h"
uint32 RSerial::_baudRate = 9600;
bool RSerial::_connected = false;
uint16 RSerial::_msgSize = 255;
RSerial::RSerial()
{
}
RSerial::~RSerial()
{
}
bool RSerial::Connect(uint32 baudRate)
{
_baudRate = baudRate;
Serial.begin(baudRate);
_connected = true;
return _connected;
}
void RSerial::Write(Reon_Msg message)
{
if (_connected)
{
//DebugPrint("RSerial: " + string((char*)message.msg));
Serial.write(message.msg, message.size);
}
else
{
//DebugPrint("RSerial - not connected");
}
}
void RSerial::Read(void (*callback) (Reon_Msg))
{
if (_connected)
{
Reon_Msg message;
byte* buf = new byte[_msgSize];
DebugPrint("RSerial: read next...");
while (Serial.available() == 0);
uint32 size = Serial.readBytes(buf, _msgSize);
message.size = size;
message.msg = buf;
callback(message);
}
}
On the Raspi 3
void Serial::Read(std::function<void(Reon_Msg)> callback)
{
//----- CHECK FOR ANY RX BYTES -----
char rxBuffer[MSG_SIZE] = {0};
//msg.msg = rxBuffer;
if (_uartFilestream != -1)
{
int rxLength = read(_uartFilestream, (void*)rxBuffer, MSG_SIZE); //Filestream, buffer to store in, number of bytes to read (MSG_SIZE)
if (rxLength < 0)
{
//NOTE: if this occurs settings of serial com is broken --> non blocking
cout << "no bytes recieved" << endl;
}
else if (rxLength == 0)
{
//No data waiting
cout << "no data...waiting" << endl;
}
else
{
char* newMsgPtr = rxBuffer;
for (int i=0; i < rxLength; i++)
{
//cout << "next: " << (int)rxBuffer[i] << endl;
if (rxBuffer[i] == 0xFF)
{
_closeBytes++;
//cout << "close bytes: " << _closeBytes << endl;
if (_closeBytes == 1)
{
Reon_Msg msg;
//cout << "in" << endl;
std::memcpy(_currBufferPtr, newMsgPtr, i+1 - (newMsgPtr-rxBuffer));
_currBufferPtr += i+1 - (newMsgPtr-rxBuffer);
/*for (char* i=&_buffer[0]; i < _currBufferPtr; i++)
{
cout << (int)*i << endl;
}*/
msg.size = _currBufferPtr - &_buffer[0] - 1;
msg.msg = new char[msg.size];
std::memcpy(msg.msg, &_buffer[0], msg.size);
callback(msg);
_closeBytes = 0;
_currBufferPtr = &_buffer[0];
//cout << "reset to: " << (int)*_currBufferPtr << endl;
//TODO: check not necessary can check below
if (i == rxLength - 1)
{
//cout << "null" << endl;
newMsgPtr = nullptr;
}
else
{
//cout << "not null" << endl;
newMsgPtr = &rxBuffer[i+1];
}
}
}
}
if (_closeBytes < 2)
{
if (newMsgPtr != nullptr)
{
std::memcpy(_currBufferPtr, newMsgPtr, (&rxBuffer[rxLength]) - newMsgPtr);
_currBufferPtr += (&rxBuffer[rxLength]) - newMsgPtr;
/*cout << "in save" << endl;
for (char* i=&_buffer[0]; i < _currBufferPtr; i++)
{
cout << "Save: " << (int)*i << endl;
}*/
}
}
//cout << "end: -------------------" << endl;
//Bytes received
}
}
else
{
cerr << "Device " << _uartDevice << " disconnected!" << endl;
}
}
I know it’s pretty messy and error prone but I’m in the early development stage so please don’t judge 
Thank you kindly in advance