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: CBuffer.h

Revision:
0:51977f75213d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CBuffer.h	Mon Jul 13 04:38:28 2015 +0000
@@ -0,0 +1,75 @@
+/* Copyright (C) 2012 mbed.org, MIT License
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+ * and associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute,
+ * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
+ * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef CIRCBUFFER_H_
+#define CIRCBUFFER_H_
+
+template <class T>
+class CircBuffer {
+public:
+    CircBuffer(int length) {
+        write = 0;
+        read = 0;
+        size = length + 1;
+        buf = (T *)malloc(size * sizeof(T));
+    };
+
+    bool isFull() {
+        return (((write + 1) % size) == read);
+    };
+
+    bool isEmpty() {
+        return (read == write);
+    };
+
+    void queue(T k) {
+        if (isFull()) {
+            read++;
+            read %= size;
+        }
+        buf[write++] = k;
+        write %= size;
+    }
+    
+    void flush() {
+        read = 0;
+        write = 0;
+    }
+    
+
+    uint32_t available() {
+        return (write >= read) ? write - read : size - read + write;
+    };
+
+    bool dequeue(T * c) {
+        bool empty = isEmpty();
+        if (!empty) {
+            *c = buf[read++];
+            read %= size;
+        }
+        return(!empty);
+    };
+
+private:
+    volatile uint32_t write;
+    volatile uint32_t read;
+    uint32_t size;
+    T * buf;
+};
+
+#endif