mbed-os/libraries/tests/mbed/ticker_3/main.cpp

#include "mbed.h"

void ticker_callback_1(void);
void ticker_callback_2(void);

DigitalOut led0(LED1);
DigitalOut led1(LED2);
Ticker ticker;

void print_char(char c = '*')
{
    printf("%c", c);
    fflush(stdout);
}

void ticker_callback_2(void)
{
    ticker.detach();
    ticker.attach(ticker_callback_1, 1.0);
    led1 = !led1;
    print_char();
}

void ticker_callback_1(void)
{
    ticker.detach();
    ticker.attach(ticker_callback_2, 1.0);
    led0 = !led0;
    print_char();
}

int main(void)
{
    ticker.attach(ticker_callback_1, 1.0);
    while(1);
}