Communicating with attached computer

When you are developing code for the Flight Computer it is often useful to send diagnostic messages to a computer attached to the Flight Computer via a USB cable. In this short example, a Serial object called pc is created that is attached to the built-in USB transmit and receive lines. By default this will communicate at 9600 baud (as expected by PlatformIO’s monitor).

The standard C function printf is used to send information to the computer. More details about the options for the format string can be found at C++ references.

main.cpp

#include <mbed.h>

Serial pc(USBTX, USBRX);

int main() {
  pc.printf("Hello, world!\r\n");  // the special code \r\n moves to the next line

  int value = 10;
  pc.printf("The value is %i\r\n", value);  // % codes indicate where values should be inserted

  float var1 = 22.2;
  int var2 = 0xFF;

  pc.printf("Multiple values can be in the same statement: %f, %X\r\n", var1, var2);
}

After compiling () and downloading () the program to the mbed, you can observe the output on the computer using PlatformIO’s monitor (launched by clicking on ).