Serial passthrough using WIZwiki-W7500 and gainspan-WiFi-mod

#include "mbed.h"
#include "CBuffer.h"
 
DigitalOut led1(LED1);
DigitalOut led4(LED4);
 
RawSerial pc(USBTX, USBRX); // tx, rx
RawSerial dev(D1, D0); // tx, rx for WIZwiki-W75000
 
#define ASYNC_DEBUG 0
 
#if ASYNC_DEBUG
////////////////////////////////////////////////////////////////////////////////////////////////
// mbed Async Debug
Timeout timer_buffer_debug;
CircBuffer<char> async_debugbufer(1024);
 
void print_debugbuffer()
{
    char c=0;
    while ( async_debugbufer.available() ) {
        async_debugbufer.dequeue(&c);
        pc.putc(c);
    }
    timer_buffer_debug.attach(&print_debugbuffer, 0.1);
}
 
#include <stdarg.h>
static char debug_line[64];
void mbed_async_debug(const char *format, ...)
{
    va_list args;
    
    va_start(args, format);
    
    vsnprintf(debug_line, sizeof(debug_line), format, args);
    int length = strlen(debug_line);
    
    for (int i=0; i<length; i++)
        async_debugbufer.queue(debug_line[i]);
    
    va_end(args);
}
 
// mbed Async Debug Print, You can move below line to mbed-src.
void (*dbg_f)(const char *format, ...);
extern void (*dbg_f)(const char *format, ...);
 
#endif
 
void dev_recv()
{
    led1 = !led1;
    while(dev.readable()) {
        pc.putc(dev.getc());
    }
}
 
void pc_recv()
{
    led4 = !led4;
    while(pc.readable()) {
        dev.putc(pc.getc());
    }
}
 
int main()
{
    for (int i=0; i<10; i++)
    {        
        led1 = !led1;
        led4 = !led4;
        wait(0.1);
    }
    
    pc.baud(115200);
    dev.baud(9600);
    
    pc.printf("Serial Passthrough Started. \r\n");
    
#if ASYNC_DEBUG
    dbg_f = &mbed_async_debug;
    timer_buffer_debug.attach(&print_debugbuffer, 0.1);
#endif
 
    pc.attach(&pc_recv, Serial::RxIrq);
    dev.attach(&dev_recv, Serial::RxIrq);
    
    while(1) {
        wait(1);
    }
}