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dht11.c
159 lines (128 loc) · 3.17 KB
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dht11.c
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#include "dht11.h"
uint16_t read_cycle(uint16_t cur_tics, uint8_t neg_tic){
uint16_t cnt_tics;
if (cur_tics < MAX_TICS) cnt_tics = 0;
if (neg_tic){
while (!GPIO_ReadInputDataBit(DHT11_PORT, DHT11_PIN)&&(cnt_tics<MAX_TICS)){
cnt_tics++;
}
}
else {
while (GPIO_ReadInputDataBit(DHT11_PORT, DHT11_PIN)&&(cnt_tics<MAX_TICS)){
cnt_tics++;
}
}
return cnt_tics;
}
uint8_t DHT11_RawRead(uint8_t *buf){
// GPIO_InitTypeDef GPIO_InitStructure;
uint16_t dt[42];
uint16_t cnt;
uint8_t i, check_sum;
// GPIO_InitStructure.GPIO_Pin = DHT11_PIN;
// GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
// GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
// GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
// GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
// GPIO_Init(DHT11_PORT, &GPIO_InitStructure);
pin_mode(DHT11_PORT, DHT11_PIN, GPIO_MODE_OUT2_PP);
//reset DHT11
Delay(500);
GPIO_LOW(DHT11_PORT,DHT11_PIN);
Delay(20);
GPIO_HIGH(DHT11_PORT,DHT11_PIN);
// GPIO_InitStructure.GPIO_Pin = DHT11_PIN;
// GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
// GPIO_InitStructure.GPIO_Speed = GPIO_Speed_40MHz;
// GPIO_Init(DHT11_PORT, &GPIO_InitStructure);
pin_mode(DHT11_PORT, DHT11_PIN, GPIO_MODE_IN);
//start reading
cnt = 0;
for(i=0;i<83 && cnt<MAX_TICS;i++){
if (i & 1){
cnt = read_cycle(cnt, 1);
}
else {
cnt = read_cycle(cnt, 0);
dt[i/2]= cnt;
}
}
//release line
GPIO_HIGH(DHT11_PORT, DHT11_PIN);
for (i = 0; i<5; i++) buf[i]=0;
if (cnt>=MAX_TICS) return DHT11_NO_CONN;
//convert data
for(i=2;i<42;i++){
(*buf) <<= 1;
if (dt[i]>20) {
(*buf)++;
}
if (!((i-1)%8) && (i>2)) {
buf++;
}
}
//calculate checksum
buf -= 5;
check_sum = 0;
for(i=0;i<4;i++){
check_sum += *buf;
buf++;
}
if (*buf != check_sum) return DHT11_CS_ERROR;
return DHT11_OK;
//return check_sum;
}
uint8_t DHT11_pwm_Read(uint8_t *buf, uint32_t *dt, uint32_t *cnt){
uint8_t i, check_sum;
*cnt = 0;
for (i = 0; i<43; i++) dt[i]=0;
pin_mode(DHT11_PORT, DHT11_PIN, GPIO_MODE_OUT2_PP);
GPIO_LOW(DHT11_PORT, DHT11_PIN);
Delay(20);
GPIO_HIGH(DHT11_PORT, DHT11_PIN);
tim_init_pwm_cnt(DHT11_PORT, DHT11_PIN);
Delay(20);
//pin_mode(TIM2_GPIO, TIM2_CH1, GPIO_MODE_OUT2_PP);
//GPIO_HIGH(TIM2_GPIO, TIM2_CH1);
for (i = 0; i<5; i++) buf[i]=0;
if (*cnt==0) return DHT11_NO_CONN;
//convert data
for(i=3;i<42;i++){
(*buf) <<= 1;
if (dt[i]>2000) {
(*buf)++;
}
if (!((i-2)%8) && (i>3)) {
buf++;
}
}
//calculate checksum
buf -= 5;
check_sum = 0;
for(i=0;i<4;i++){
check_sum += *buf;
buf++;
}
if (*buf != check_sum) return DHT11_CS_ERROR;
return DHT11_OK;
//return check_sum;
}
float DHT22_Humidity(uint8_t *buf){
float res;
res = buf[0] * 256 + buf[1];
res /= 10.0;
return res;
}
float DHT22_Temperature(uint8_t *buf){
float res;
res = (buf[2] & 0x7F)* 256 + buf[3];
res /= 10.0;
if (buf[2] & 0x80) res *= -1;
return res;
}
uint8_t DHT11_Humidity(uint8_t *buf){
return buf[0];
}
uint8_t DHT11_Temperature(uint8_t *buf){
return buf[2];;
}