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55 lines
1.5 KiB
C
55 lines
1.5 KiB
C
2 years ago
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#include "dht20.h"
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#define DHT20_ADDRESS 0x70
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// 初始化DHT20
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void DHT20_Init(void) {
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uint8_t read_buf = 0;
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HAL_Delay(500); //等待DHT20上电稳定
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HAL_I2C_Master_Receive(&hi2c1, DHT20_ADDRESS, &read_buf, 1, 10);
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if ((read_buf & 0x18) != 0x18) {
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DHT20_Reset_REG(0x1B);
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DHT20_Reset_REG(0x1C);
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DHT20_Reset_REG(0x1E);
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}
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}
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// DHT20初始化寄存器
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void DHT20_Reset_REG(uint8_t addr) {
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uint8_t send_buf[3] = { 0x00 };
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send_buf[0] = addr;
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HAL_I2C_Master_Transmit(&hi2c1, DHT20_ADDRESS, send_buf, 3, 10);
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HAL_Delay(5);
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HAL_I2C_Master_Receive(&hi2c1, DHT20_ADDRESS, send_buf, 3, 10);
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HAL_Delay(10);
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send_buf[0] = 0xB0 | addr;
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HAL_I2C_Master_Transmit(&hi2c1, DHT20_ADDRESS, send_buf, 3, 10);
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}
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// DHT20读温湿度
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void DHT20_Get_T_H(float *Temperature, float *Humidity) {
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uint8_t cmd_ac[3] = { 0xAC, 0x33, 0x00 };
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uint8_t read_buf[6] = { 0 };
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int32_t data = 0;
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int16_t hum = 0, tmp = 0;
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HAL_I2C_Master_Transmit(&hi2c1, DHT20_ADDRESS, cmd_ac, 3, 10);
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HAL_Delay(200);
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HAL_I2C_Master_Receive(&hi2c1, DHT20_ADDRESS, read_buf, 6, 10);
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if ((read_buf[0] & 0x80) != 0x80) {
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data = (data | read_buf[1]) << 8;
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data = (data | read_buf[2]) << 8;
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data = (data | read_buf[3]);
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data = data >> 4;
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hum = data * 100 * 10 / 1024 / 1024;
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data = 0;
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data = (data | read_buf[3]) << 8;
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data = (data | read_buf[4]) << 8;
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data = (data | read_buf[5]);
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data = data & 0xFFFFF;
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tmp = data * 200 * 10 / 1024 / 1024 - 500;
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*Temperature = ((float) tmp) / 10.0f;
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*Humidity = ((float) hum) / 10.0f;
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}
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}
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