wayne roberts / Mbed 2 deprecated basic_serial_console

demonstration of using serial port as console/terminal

Dependencies:   mbed

Demonstration of using serial port with a dumb terminal. Such as teraterm. This example uses serial port at 57600bps.

purpose

provide quick/easy user interface.

features

  • backspace key stops at start of line
  • <enter> on empty line repeats last command
  • Ctrl-C can be used to abort something

teraterm console

reset
> ?
.       print status
led     toggle LED
da<%d>  get/set my_data
> .
LED1:0
my_data:0
> led
> .
LED1:1
my_data:0
> da
data:0
> da1337
data:1337
> .
LED1:1
my_data:1337
> led
>
>
>
>

main.cpp

Committer:
dudmuck
Date:
2014-11-06
Revision:
0:9a142eb22e83

File content as of revision 0:9a142eb22e83:

#include "mbed.h"

Serial pc(USBTX, USBRX);
char pcbuf[64];

DigitalOut myled(LED1);

uint16_t my_data;

void service_something()
{
    /* poll something while waiting for keyboard */
}

int get_kbd_str(char* buf, int size)
{
    char c;
    int i;
    static int prev_len;
    
    for (i = 0;;) {
        if (pc.readable()) {
            c = pc.getc();
            if (c == 8) {   // backspace
                if (i > 0) {
                    pc.putc(8);
                    pc.putc(' ');
                    pc.putc(8);
                    i--;
                }
            } else if (c == '\r') {
                if (i == 0) {
                    return prev_len; // repeat previous
                } else {
                    buf[i] = 0; // null terminate
                    prev_len = i;
                    return i;
                }
            } else if (c == 3) {
                // ctrl-C abort
                return -1;
            } else if (i < size) {
                buf[i++] = c;
                pc.putc(c);
            }
        } else {
            service_something();
        }
    } // ...for()
}

void
print_status()
{
    printf("LED1:%d\r\n", myled.read());
    printf("my_data:%d\n", my_data);
}

void console()
{
    int len, n;
    
    len = get_kbd_str(pcbuf, sizeof(pcbuf));
    if (len < 0) {
        printf("abort\r\n");
        return;
    }
    
    printf("\r\n");
    if (len == 1) {
        /* single character handling */
        switch (pcbuf[0]) {
            case '?':
                printf(".       print status\r\n");
                printf("led     toggle LED\r\n");
                printf("da<%%d>  get/set my_data\r\n");
                break;
            case '.':
                print_status();
                break;
        } // ...switch (pcbuf[0])
    } else if (pcbuf[0] == 'l' && pcbuf[1] == 'e' && pcbuf[2] == 'd') {
        if (myled.read())   // invert LED state
            myled = 0;
        else
            myled = 1;
    } else if (pcbuf[0] == 'd' && pcbuf[1] == 'a') {
        if (pcbuf[2] >= '0' && pcbuf[2] <= '9') {
            sscanf(pcbuf+2, "%d", &n);
            my_data = n;    // set user data
        }
        printf("data:%d\r\n", my_data);  // show current value;
    }

    printf("> ");
    fflush(stdout);
}

int main()
{  
    pc.baud(57600);
    printf("\r\nreset\r\n");
    
    printf("> ");
    fflush(stdout);
    
    while (1) {
        console();
    }
}