Boost asio serial port "end of file"

Question

I am trying to read serial data coming from arduino, but when I run my program it only reads all the data in the buffer, the data that was actually send before the program started. And then i terminates with the following error:

terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::system::system_error> >'
what():  read: End of file
Aborted (core dumped)

I also do not even want the data from before the program was executed. Here is my c++ code:

#include <iostream>
#include <stdint.h>

#include <boost/asio.hpp>
#include <boost/asio/serial_port.hpp>

using namespace boost;

int main() {
    asio::io_service io;
    asio::serial_port port(io);

    port.open("/dev/ttyUSB0");
    port.set_option(asio::serial_port_base::baud_rate(115200));

    char d;

    while ( true ) {
        asio::read(port, asio::buffer(&d, 1));
        std::cout << d << std::endl;
    }

    port.close();
}

As far as I know the read function should be blocking, so it waits for the next input, right? Then how can it reach the end of "file"?

Hi, I'm having the same problem. Even worse, the *binary* that worked yesterday gives the same problem as you today. Possibly due to some timeout settings. — Atilla Filiz, Aug 27 '17 at 16:16
So I ran the exact same code again today, with the exact same compilation process and now it magically works... — Rasmus Tollund, Aug 28 '17 at 15:17

Atilla Filiz · Accepted Answer · 2017-08-27T17:52:33.030

5

This is what worked for me. You need to give your serial port a minimum character limit to have a blocking capability.

stty -F /dev/ttyUSB5 115200 line 0 min 1 time 0

EDIT: A better option seems to just set the port to raw mode.

stty -F /dev/ttyUSB0 raw

edited Aug 27 '17 at 17:52

answered Aug 27 '17 at 16:31

Atilla Filiz

2,383
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Where am I supposed to put this? – Rasmus Tollund Aug 28 '17 at 15:17
If using Linux, your command line before running your program. – Atilla Filiz Aug 28 '17 at 17:55

Rasmus Tollund · Answer 2 · 2017-08-28T18:10:57.687

0

So I have figured out that after running Arduino IDE as root, to allow serial communication, my programs stops working and I get the EOF error. Even after Arduino IDE has been closed it does not work, restarting my pc allows it to work again.

But Atilla Filiz answers solves this.

edited Aug 28 '17 at 18:10

answered Aug 28 '17 at 16:40

Rasmus Tollund

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1
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Boost asio serial port "end of file"

2 Answers2