DHT11 数字温湿度传感器是一款含有已校准数字信号输出的温湿度复合传感器

/* * Copyright (c) 2006-2018, RT-Thread Development Team * * SPDX-License-Identifier: Apache-2.0 * * Change Logs: * Date Author Notes * 2019-08-01 LuoGong the first version. * 2019-08-15 MurphyZhao add lock and modify code style * */ #include "sensor_dallas_dht11.h" #include <rtdevice.h> #include <rthw.h> #include "sensor.h" #include "board.h" #include <stdint.h> #define SENSOR_DEBUG #define DBG_TAG "sensor.dht11" #ifdef SENSOR_DEBUG #define DBG_LVL DBG_LOG #else #define DBG_LVL DBG_ERROR #endif /* SENSOR_DEBUG */ #include <rtdbg.h> #define SENSOR_TEMP_RANGE_MAX (100) #define SENSOR_TEMP_RANGE_MIN (0) #define SENSOR_HUMI_RANGE_MAX (100) #define SENSOR_HUMI_RANGE_MIN (0) #ifndef RT_USING_PIN #error "Please enable RT_USING_PIN" #endif #ifndef RT_SENSOR_VENDOR_DALLAS #define RT_SENSOR_VENDOR_DALLAS (7u) #endif #ifndef rt_hw_us_delay RT_WEAK void rt_hw_us_delay(rt_uint32_t us) { rt_uint32_t delta; us = us * (SysTick->LOAD / (1000000 / RT_TICK_PER_SECOND)); delta = SysTick->VAL; while (delta - SysTick->VAL < us) continue; } #endif static void dht11_reset(rt_base_t pin) { rt_pin_mode(pin, PIN_MODE_OUTPUT); rt_pin_write(pin, PIN_LOW); rt_thread_mdelay(20); /* 20ms */ rt_pin_write(pin, PIN_HIGH); rt_hw_us_delay(30); /* 30us*/ } static uint8_t dht11_check(rt_base_t pin) { uint8_t retry = 0; rt_pin_mode(pin, PIN_MODE_INPUT); while (rt_pin_read(pin) && retry < 100) { retry++; rt_hw_us_delay(1); } if(retry >= 100) { return CONNECT_FAILED; } retry = 0; while (!rt_pin_read(pin) && retry < 100) { retry++; rt_hw_us_delay(1); }; if(retry >= 100) { return CONNECT_FAILED; } return CONNECT_SUCCESS; } static uint8_t dht11_read_bit(rt_base_t pin) { uint8_t retry = 0; while (rt_pin_read(pin) && retry < 100) { retry++; rt_hw_us_delay(1); } retry = 0; while (!rt_pin_read(pin) && retry < 100) { retry++; rt_hw_us_delay(1); } rt_hw_us_delay(40); if(rt_pin_read(pin)) return 1; return 0; } static uint8_t dht11_read_byte(rt_base_t pin) { uint8_t i, dat = 0; for (i = 1; i <= 8; i++) { dat <<= 1; dat |= dht11_read_bit(pin); } return dat; } static uint8_t dht11_read_Data(rt_base_t pin,uint8_t *temp,uint8_t *humi) { uint8_t i, buf[5]; dht11_reset(pin); if(dht11_check(pin) == 0) { for(i=0; i<5; i++) /* read 40 bits */ { buf[i] = dht11_read_byte(pin); } if((buf[0] + buf[1] + buf[2] + buf[3]) == buf[4]) { *humi = buf[0]; *temp = buf[2]; } } else { return 1; } return 0; } uint8_t dht11_init(rt_base_t pin) { uint8_t ret = 0; dht11_reset(pin); ret = dht11_check(pin); if (ret != 0) { dht11_reset(pin); ret = dht11_check(pin); } return ret; } int32_t dht11_get_temperature(rt_base_t pin) { static int32_t temOLD = 0; uint8_t humi=0, temp = 0; int32_t temNEW; dht11_read_Data(pin, &temp, &humi); temNEW = (humi << 16)|(temp<<0); if((temNEW != temOLD) && (temNEW !=0)) { temOLD = temNEW; } return temOLD; } static rt_size_t dht11_polling_get_data(rt_sensor_t sensor, struct rt_sensor_data *data) { rt_int32_t temperature_humidity; temperature_humidity = dht11_get_temperature((rt_base_t)sensor->config.intf.user_data); data->data.temp = temperature_humidity; data->timestamp = rt_sensor_get_ts(); return 1; } static rt_size_t dht11_fetch_data(struct rt_sensor_device *sensor, void *buf, rt_size_t len) { RT_ASSERT(buf); if (sensor->config.mode == RT_SENSOR_MODE_POLLING) { return dht11_polling_get_data(sensor, buf); } return 0; } static rt_err_t dht11_control(struct rt_sensor_device *sensor, int cmd, void *args) { return RT_EOK; } static struct rt_sensor_ops sensor_ops = { dht11_fetch_data, dht11_control }; static struct rt_sensor_device dht11_dev; int rt_hw_dht11_init(const char *name, struct rt_sensor_config *cfg) { rt_err_t result = RT_EOK; rt_sensor_t sensor = &dht11_dev; rt_memset(sensor, 0x0, sizeof(struct rt_sensor_device)); if (!dht11_init((rt_base_t)cfg->intf.user_data)) { sensor->module = rt_calloc(1, sizeof(struct rt_sensor_module)); if (sensor->module == RT_NULL) { LOG_E("Memory error."); result = -RT_ENOMEM; goto __exit; } sensor->info.type = RT_SENSOR_CLASS_TEMP ; sensor->info.vendor = RT_SENSOR_VENDOR_DALLAS; sensor->info.model = "DHT11"; sensor->info.unit = RT_SENSOR_UNIT_DCELSIUS; sensor->info.intf_type = RT_SENSOR_INTF_ONEWIRE; sensor->info.range_max = SENSOR_TEMP_RANGE_MAX; sensor->info.range_min = SENSOR_TEMP_RANGE_MIN; sensor->info.period_min = 100; /* Read ten times in 1 second */ sensor->config = *cfg; sensor->ops = &sensor_ops; /* dht11 sensor register */ result = rt_hw_sensor_register(sensor, name, RT_DEVICE_FLAG_RDONLY, RT_NULL); if (result != RT_EOK) { LOG_E("device register err code: %d", result); goto __exit; } } else { LOG_E("dht11 init failed"); result = -RT_ERROR; goto __exit; } return RT_EOK; __exit: if (sensor->module) rt_free(sensor->module); return result; }