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);
}

CBuffer.h

Committer:
SteveKim
Date:
2015-07-13
Revision:
0:51977f75213d

File content as of revision 0:51977f75213d:

/* 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