Steve Kim / AsyncPrint

async_test for test

Dependencies:   mbed-src

This is about asynchronous uart output.

When I need to debug my software in a ISR or a task(thread), I worried that printf() might cause some abnormal result.

So, I made my uart output function like printf().

Initialize async_print

title

void timerfunction_async_print()
{
    char c=0;

    while ( buffer_async_print.available() ) {
        buffer_async_print.dequeue(&c);
        pc.putc(c);
    }
    timer_async_print.attach(&timerfunction_async_print, 0.1);
}

void async_print(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++)
        buffer_async_print.queue(debug_line[i]);
    
    va_end(args);
}


int main()
{
    .....................................................

    // Initialize AsyncPrint
    timer_async_print.attach(&timerfunction_async_print, 0.1);
    p_async_print = &async_print;
    
    .....................................................
}

Implementation async_print

void (*p_async_print)(const char *format, ...);

void UART0_Handler()
{
    p_async_print("IRQ : UART_IT_FLAG_RXI \r\n");
    uart_irq(UART_0, 0);
}

Diff: main.cpp

Revision:
0:51977f75213d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Jul 13 04:38:28 2015 +0000
@@ -0,0 +1,77 @@
+#include "mbed.h"
+#include "CBuffer.h"
+#include <stdarg.h>
+
+DigitalOut led1(LED1);
+DigitalOut led4(LED4);
+
+RawSerial pc(USBTX, USBRX); // tx, rx
+
+////////////////////////////////////////////////////////////////////////////////////////////////
+// mbed Async Debug Print
+Timeout timer_async_print;
+CircBuffer<char> buffer_async_print(1024);
+static char debug_line[64];
+
+void timerfunction_async_print()
+{
+    char c=0;
+
+    while ( buffer_async_print.available() ) {
+        buffer_async_print.dequeue(&c);
+        pc.putc(c);
+    }
+    timer_async_print.attach(&timerfunction_async_print, 0.1);
+}
+
+void async_print(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++)
+        buffer_async_print.queue(debug_line[i]);
+    
+    va_end(args);
+}
+
+extern void (*p_async_print)(const char *format, ...);
+////////////////////////////////////////////////////////////////////////////////////////////////
+
+
+extern int rx_irq_counter;
+void pc_recv()
+{
+    led4 = !led4;
+    while(pc.readable()) {
+        pc.printf("RECV [%c]\r\n", pc.getc());
+    }
+}
+
+int main()
+{
+    for (int i=0; i<20; i++)
+    {        
+        led1 = !led1;
+        led4 = !led4;
+        wait(0.05);
+    }
+
+    // Initialize AsyncPrint
+    timer_async_print.attach(&timerfunction_async_print, 0.1);
+    p_async_print = &async_print;
+    
+    pc.baud(115200);    
+    pc.printf("AsyncPrint Test. \r\n");
+    
+    pc.attach(&pc_recv, Serial::RxIrq);
+    
+    while(1) {
+        wait(1);
+    }
+}
+