stm8s ds18b20 代码

/******** STM8S-Discovery DS18B20 Test ******** * 版本.........: 1.0 * 作者.........: 陈利栋 * 目标.........: STM8S105C6T6 * 文件名.......: main.c * 开发环境.....: IAR for STM8 V1.1 * 创建时间.....: 2010.09.10 * 最后修改.....: 2010.09.10 ***********************************************/ #include <iostm8s105c6.h> #include <stdio.h> #define BAUD_RATE 9600 //波特率 #define F_MASTER 16000000 //主频率 #define DS18B20_DQ_OUT PG_DDR_DDR0 = 1 //输出 #define DS18B20_DQ_IN PG_DDR_DDR0 = 0 //输入 #define DS18B20_DQ_HIGH PG_ODR_ODR0 = 1 //拉高 #define DS18B20_DQ_LOW PG_ODR_ODR0 = 0 //拉低 #define DS18B20_DQ_PULL_UP PG_CR1_C10 = 1 //上拉 #define DS18B20_DQ_FLOATING PG_CR1_C10 = 0 //浮空 #define DS18B20_DQ_PUSH_PULL PG_CR1_C10 = 1 //推挽 #define DS18B20_DQ_OPEN_DRAIN PG_CR1_C10 = 0 //开漏 #define DS18B20_DQ_VALUE PG_IDR_IDR0 //DQ值 //串口配置 //数据位:8 //停止位:1 //校验位:None void UART_Init(void) { UART2_CR2_TEN = 1; UART2_CR2_REN = 1; UART2_CR2_RIEN = 1; UART2_BRR2 = ((unsigned char)((F_MASTER / BAUD_RATE) & 0x0f)) + (((unsigned char)((F_MASTER / BAUD_RATE) >> 8)) & 0xf0); UART2_BRR1 = ((unsigned char)((F_MASTER / BAUD_RATE) >> 4)); } void UART_TxByte(unsigned char _data) { while (UART2_SR_TXE == 0); UART2_DR = _data; } int putchar(int c) { UART_TxByte(c); return c; } void _delay_us(unsigned int i) { i *= 3; while(--i); } void _delay_ms(unsigned int i) { while(i--) { _delay_us(1000); } } void DS18B20_Init(void) { DS18B20_DQ_OUT; DS18B20_DQ_PUSH_PULL; DS18B20_DQ_HIGH; _delay_us(10); DS18B20_DQ_LOW; _delay_us(600); //复位脉冲 DS18B20_DQ_IN; DS18B20_DQ_PULL_UP; _delay_us(100); while(DS18B20_DQ_VALUE == 1); _delay_us(400); } void DS18B20_WriteByte(unsigned char _data) { unsigned char i = 0; DS18B20_DQ_OUT; for (i = 0; i < 8; i++) { DS18B20_DQ_LOW; _delay_us(2); if (_data & 0x01) { DS18B20_DQ_HIGH; } _data >>= 1; _delay_us(60); DS18B20_DQ_HIGH; } } unsigned char DS18B20_ReadByte(void) { unsigned char i = 0, _data = 0; for (i = 0; i < 8; i++) { DS18B20_DQ_OUT; DS18B20_DQ_LOW; _delay_us(5); _data >>= 1; DS18B20_DQ_HIGH; DS18B20_DQ_IN; if (DS18B20_DQ_VALUE) { _data |= 0x80; } DS18B20_DQ_OUT; DS18B20_DQ_HIGH; _delay_us(60); } return _data; } float DS18B20_ReadTemperature(void) { unsigned char temp = 0; float t = 0; DS18B20_Init(); DS18B20_WriteByte(0xcc); DS18B20_WriteByte(0x44); DS18B20_Init(); DS18B20_WriteByte(0xcc); DS18B20_WriteByte(0xbe); temp = DS18B20_ReadByte(); t = (((temp & 0xf0) >> 4) + (temp & 0x07) * 0.125); temp = DS18B20_ReadByte(); t += ((temp & 0x0f) << 4); return t; } int main(void) { CLK_SWCR_SWEN = 1; CLK_SWR = 0xB4; //HSE selected as master clock source UART_Init(); printf("********* STM8S-Discovery DS18B20 Test *********\r\n"); printf("Build: %s %s\r\n", __DATE__, __TIME__); asm("rim"); while(1) { _delay_ms(1000); printf("%.3f ", DS18B20_ReadTemperature()); } } #pragma vector = UART2_R_RXNE_vector __interrupt void UART2_IRQHandler(void) { if (UART2_SR_RXNE == 1) { UART_TxByte(UART2_DR); } }