【平头哥RVB2601创意应用开发】模拟UART之三 实现FIFO接收
<p>硬件的串口是有FIFO功能的，这样接收进来的数据会放到缓冲区里。由于GPIO摸拟的没有缓冲，所以就自己“抄”了一个FIFO的作品。</p><p>fifi.c</p>
<pre>
<code>/**************FIFO Begin**************************************************/
/*溢出标志：0-正常，-1-溢出*/
#include <board.h>
#include <aos/aos.h>
#define TAG "FFO:"
#define FLAGS_OVERRUN 0x0001
aos_mutex_t test_mutex;
/*
buf- 缓冲区地址
size- 大小
free- 空余容量
putP- 下一个数据写入位置
getP- 下一个数据独处位置
*/
struct FIFO8{
char *buf;
int putP,getP,size,free,flags;
aos_mutex_t mutex;
};
struct FIFO8 _FIFO8;
int fifo8_init(struct FIFO8 *fifo,int size);
int fifo8_putPut(struct FIFO8 *fifo, char data);//not mutiply thread safe
int fifo8_get(struct FIFO8 *fifo); //not mutiply thread safe
void fifo8_status(struct FIFO8 *fifo,int *len);
void fifo8_free(struct FIFO8 *fifo,int *len);
int fifo8_write(struct FIFO8 *fifo,char *data,int len);
int fifo8_read(struct FIFO8 *fifo,char *data,int len);
/*初始化*/
intfifo8_init(struct FIFO8 *fifo,int size) {
int ret=0;
fifo->flags=0;
fifo->free=size;
fifo->size=size;
fifo->putP=0;
fifo->getP=0;
fifo->buf=(char *)malloc(size);
if(fifo->buf == NULL){
LOGD(TAG,"malloc fifo buffer failed!\n");
return -1;
}
ret =aos_mutex_is_valid(&fifo->mutex);
if(ret <0){
LOGD(TAG,"init mutex failed!\n");
return -1;
}
LOGD(TAG,"init mutex OK!\n");
return 0;
}
/*向FIFO 中写入1个数据 */
int fifo8_putPut(struct FIFO8 *fifo, char data){
if(fifo->free==0){
fifo->flags |= FLAGS_OVERRUN;
return -1;
}
fifo->buf = data;
fifo->putP++;
//循环队列缓冲区
if(fifo->putP == fifo->size){
fifo->putP = 0;
}
fifo->free--;
return 0;
}
/*从FIFO 中取出一个数据 */
int fifo8_get(struct FIFO8 *fifo){
int data;
if(fifo->free == fifo->size){
return -1;
}
data = fifo->buf;
//fifo->getP++;
if(fifo->getP == fifo->size){//用来实现循环
fifo->getP = 0;
}
fifo->free++;
return data;
}
/*写入len个字节，返回写入的字节数*/
int fifo8_write(struct FIFO8 *fifo,char *data,int len){
int i=0;
aos_mutex_lock(&(fifo->mutex), AOS_WAIT_FOREVER);
if(fifo->free < len) {
aos_mutex_unlock(&(fifo->mutex));
LOGD(TAG,"the free size in not enough!\n");
return 0;
}
else {
LOGI(TAG,"current fifo->putP =%d \n",fifo->putP);
for(i=0;i<len;i++){
fifo->buf = *(data+i);
//循环队列缓冲区
if(fifo->putP == fifo->size){
fifo->putP = 0;
}
fifo->free--;
}
}
aos_mutex_unlock(&(fifo->mutex));
return len;
}
/*读出len个字节，返回读出的字节数*/
int fifo8_read(struct FIFO8 *fifo,char *data,int len){
int i=0;
aos_mutex_lock(&(fifo->mutex),AOS_WAIT_FOREVER);
if(fifo->size!=fifo->free){
LOGD(TAG,"current fifo->getP =%d \n",fifo->getP);
for(i=0;; i++){
*(data+i) =fifo->buf;
if(fifo->getP == fifo->size){//用来实现循环
fifo->getP = 0;
}
fifo->free++;
if(fifo->size==fifo->free){
LOGD(TAG,"the buffer is no data left!\n");
aos_mutex_unlock(&(fifo->mutex));
return i+1;
}
if(i+1==len){
LOGD(TAG,"read data finish!\n");
break;
}
}
}
else{
LOGI(TAG,"the buffer is empty!\n");
aos_mutex_unlock(&(fifo->mutex));
return 0;
}
aos_mutex_unlock(&(fifo->mutex));
return len;
}
/*缓冲区被使用容量*/
void fifo8_status(struct FIFO8 *fifo,int *used){
aos_mutex_lock(&(fifo->mutex),AOS_WAIT_FOREVER);
*used = fifo->size - fifo->free;
aos_mutex_unlock(&(fifo->mutex));
}
/*缓冲区剩余容量*/
void fifo8_free(struct FIFO8 *fifo ,int *free){
aos_mutex_lock(&(fifo->mutex),AOS_WAIT_FOREVER);
*free = fifo->free;
aos_mutex_unlock(&(fifo->mutex));
}</code></pre>
<p>2、初始化缓冲区：fifo8_init(&_FIFO8,64);</p>
<p>3、向缓冲区压入数据：</p>
<pre>
<code> fifo8_putPut(&_FIFO8,io_uart_para.vm_uart_rx_byte);//将接收的数据压入缓冲区
// io_uart_para.vm_uart_rx_buf = io_uart_para.vm_uart_rx_byte;
// io_uart_para.vm_uart_rx_flag = io_uart_para.vm_uart_rx_flag +1; </code></pre>
<p>4、取出数据，输出到模拟串口：</p>
<pre>
<code> while(1)
{
i = fifo8_get(&_FIFO8);
if(i == -1)
{
break;
}
else{
send_Char(i);
}
}
aos_msleep(1);</code></pre>
<p>实验结果：还不是很理想，每200ms 发送一次，有丢包或者数据不对的方。可能接收的数据要做CRC，这样安全稳靠一些。</p>
<p> 如果是一秒钟一次，是没问题，有精力再调一下，或者哪位高手帮忙看一下。</p>
<p> 至此接串口模拟工程完一段落。下一辑，读取电流传感器。</p>
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