esp-open-rtos/examples/serial_echo/serial_echo.c

41 lines
1.1 KiB
C

/* Extremely simple example that just reads from stdin and echoes back on stdout
*
* Has an easter egg, which is if you type "QUACK" it'll quack 3 times back at you.
*
* This example code is in the public domain
*/
#include "espressif/esp_common.h"
#include <esp/uart.h>
#include <string.h>
void user_init(void)
{
printf("SDK version:%s\n", sdk_system_get_sdk_version());
printf("Going into echo mode...\n");
/* By default stdout is line-buffered, so you only see output
after a newline is sent. This is helpful in a multithreaded
environment so output doesn't get chopped up within a line.
Here we want to see the echo immediately, so disable buffering.
*/
setbuf(stdout, NULL);
while(1) {
int c = getchar();
if(c != EOF)
putchar(c);
/* Easter egg: check for a quack! */
static int quack;
if(c == "QUACK"[quack]) {
quack++;
if(quack == strlen("QUACK")) {
printf("\nQUACK\nQUACK\n");
quack = 0;
}
} else {
quack = 0;
}
}
}