概述：
在使用STM8L101F3这款单片机时，由于它只有8K的flash，空间非常小，只要调用C库函数printf编译后整个文件很大，直接程序溢出。这也就意味着我们实现printf串口打印调试就没办法进行。既然使用不了库函数，那么我们就可以自己动手封装类似printf的函数，这样我们就可以实现数据串口打印啦。这里就直接放上我的STM8L101F3的部分源码了，希望可以给你一些参考。
源码：
#include "stdarg.h"
#include "stm8l10x.h"
void USART_Config(void)
{
/*Set the USART RX and USART TX at high level*/
GPIO_ExternalPullUpConfig(GPIOC,GPIO_Pin_3|GPIO_Pin_4, ENABLE);
/* Enable USART clock */
CLK_PeripheralClockConfig(CLK_Peripheral_USART, ENABLE);
USART_DeInit();
USART_Init((uint32_t)9600, USART_WordLength_8D, USART_StopBits_1,
USART_Parity_No, (USART_Mode_TypeDef)(USART_Mode_Rx | USART_Mode_Tx));
USART_Cmd(DISABLE);
enableInterrupts();
USART_Cmd(ENABLE);
}
/*发送串口数据*/
void send_uart_data(uint8_t data)
{
while (USART_GetFlagStatus(USART_FLAG_TXE) == RESET);
USART_SendData8(data);
}
/*
功能：将int型数据转为2，8，10，16进制字符串
参数：value --- 输入的int整型数
str --- 存储转换的字符串
radix --- 进制类型选择
注意：8位单片机int字节只占2个字节
*/
char *sky_itoa(int value, char *str, unsigned int radix)
{
char list[] = "0123456789ABCDEF";
unsigned int tmp_value;
int i = 0, j, k = 0;
if (NULL == str) {
return NULL;
}
if (2 != radix && 8 != radix && 10 != radix && 16 != radix) {
return NULL;
}
if (radix == 10 && value < 0) {
//十进制且为负数
tmp_value = (unsigned int)(0 - value);
str[i++] = '-';
k = 1;
} else {
tmp_value = (unsigned int)value;
}
//数据转换为字符串，逆序存储
do {
str[i ++] = list[tmp_value%radix];
tmp_value /= radix;
} while(tmp_value);
str[i] = '\0';
//将逆序字符串转换为正序
char tmp;
for (j = k; j < (i+k)/2; j++) {
tmp = str[j];
str[j] = str[i-j-1+k];
str[i-j-1+k] = tmp;
}
return str;
}
/*
功能：将double型数据转为字符串
参数：value --- 输入的double浮点数
str --- 存储转换的字符串
eps --- 保留小数位选择，至少保留一个小数位,至多保留4个小数位
注意：8位单片机int字节只占2个字节
*/
void sky_ftoa(double value, char *str, unsigned int eps)
{
unsigned int integer;
double decimal;
char list[] = "0123456789";
int i = 0, j, k = 0;
//将整数及小数部分提取出来
if (value < 0) {
decimal = (double)(((int)value) - value);
integer = (unsigned int)(0 - value);
str[i ++] = '-';
k = 1;
} else {
integer = (unsigned int)(value);
decimal = (double)(value - integer);
}
//整数部分数据转换为字符串，逆序存储
do {
str[i ++] = list[integer%10];
integer /= 10;
} while(integer);
str[i] = '\0';
//将逆序字符串转换为正序
char tmp;
for (j = k; j < (i+k)/2; j++) {
tmp = str[j];
str[j] = str[i-j-1+k];
str[i-j-1+k] = tmp;
}
//处理小数部分
if (eps < 1 || eps > 4) {
eps = 4;
}
//精度问题，防止输入1.2输出1.19等情况
double pp = 0.1;
for (j = 0; j <= eps; j++) {
pp *= 0.1;
}
decimal += pp;
while (eps) {
decimal *= 10;
eps --;
}
int tmp_decimal = (int)decimal;
str[i ++] = '.';
k = i;
//整数部分数据转换为字符串，逆序存储
do {
str[i ++] = list[tmp_decimal%10];
tmp_decimal /= 10;
} while(tmp_decimal);
str[i] = '\0';
//将逆序字符串转换为正序
for (j = k; j < (i+k)/2; j++) {
tmp = str[j];
str[j] = str[i-j-1+k];
str[i-j-1+k] = tmp;
}
str[i] = '\0';
}
void mprintf(char * Data, ...)
{
const char *s;
int d;
char buf[16];
uint8_t txdata;
va_list ap;
va_start(ap, Data);
while ( * Data != 0 ) {
if ( * Data == 0x5c ) {
switch ( *++Data ) {
case 'r':
txdata = 0x0d;
send_uart_data(txdata);
Data ++;
break;
case 'n':
txdata = 0x0a;
send_uart_data(txdata);
Data ++;
break;
default:
Data ++;
break;
}
} else if ( * Data == '%') {
switch ( *++Data ) {
case 's':
s = va_arg(ap, const char *);
for ( ; *s; s++) {
send_uart_data(*((uint8_t *)s));
}
Data++;
break;
case 'd':
d = va_arg(ap, int);
sky_itoa(d, buf, 10);
for (s = buf; *s; s++) {
send_uart_data(*((uint8_t *)s));
}
Data++;
break;
case 'x': {
d = va_arg(ap, int);
sky_itoa(d, buf, 16);
for (s = buf; *s; s++) {
send_uart_data(*((uint8_t *)s));
}
Data++;
break;
}
case 'f': {
double num = va_arg(ap, double);
sky_ftoa(num, buf, 4);
for (s = buf; *s; s++) {
send_uart_data(*((uint8_t *)s));
}
Data++;
break;
}
default:
Data++;
break;
}
} else {
send_uart_data(*((uint8_t *)Data));
Data++;
}
}
}
void main(void)
{
USART_Config();
mprintf("STM8L start...\r\n");
mprintf("%f %f %f\r\n", 1.2, 12.36, -1.2364568);
mprintf("%x %x %x\r\n", 0x1035, 0x0830, 0x2018);
mprintf("%d %d %d\r\n", 12, -12345, 2);
mprintf("STM8L end...\r\n");
while (1) {
}
}
| 
楼主
标题置顶
标题高亮
