Temperature and humidity module DHT11 Product Manual www.aosong.
1、Product Overview DHT11 digital temperature and humidity sensor is a composite Sensor contains a calibrated digital signal output of the temperature and humidity. Application of a dedicated digital modules collection technology and the temperature and humidity sensing technology, to ensure that the product has high reliability and excellent long-term stability.
5、Product parameters Relative humidity Resolution: 16Bit Repeatability: ±1% RH Accuracy: At 25℃ ±5% RH Interchangeability: fully interchangeable Response time: 1 / e (63%) of 25℃ 6s 1m / s air 6s Hysteresis: <± 0.3% RH Long-term stability: <± 0.5% RH / yr in Temperature Resolution: 16Bit Repeatability: ±0.2℃ Range: At 25℃ ±2℃ Response time: 1 / e (63%) 10S Electrical Characteristics Power supply: DC 3.5～5.5V Supply Current: measurement 0.
6、Typical circuit Microprocessor and DHT11 of connection typical application circuit as shown above, DATA pull the microprocessor I / O ports are connected. 1. Typical application circuit recommended in the short cable length of 20 meters on the 5.1K pull-up resistor, the resistance of greater than 20 meters under the pull-up resistor on the lower of the actual situation. 2. When using a 3.5V voltage supply cable length shall not be greater than 20cm.
Data format: The 8bit humidity integer data + 8bit the Humidity decimal data +8 bit temperature integer data + 8bit fractional temperature data +8 bit parity bit. ◎Parity bit data definition “8bit humidity integer data + 8bit humidity decimal data +8 bit temperature integer data + 8bit temperature fractional data” 8bit checksum is equal to the results of the last eight. Example 1: 40 data is received: 0011 0101 0000 0000 0001 1000 High humidity 8 Low humidity 8 High temp.
◎Peripherals read steps Communication between the master and slave can be done through the following steps (peripherals (such as microprocessors) read DHT11 the data of steps).
End signal: Continue to output the low 50 microseconds after DHT11 the DATA pin output 40 data, and changed the input state, along with pull-up resistor goes high. But DHT11 internal re-test environmental temperature and humidity data, and record the data, waiting for the arrival of the external signal. 8、Application of information 1. Work and storage conditions Outside the sensor the proposed scope of work may lead to temporary drift of the signal up to 300%RH.
5. Resume processing Placed under extreme working conditions or chemical vapor sensor, which allows it to return to the status of calibration by the following handler. Maintain two hours in the humidity conditions of 45℃ and <10% RH (dry); followed by 20-30℃ and> 70% RH humidity conditions to maintain more than five hours. 6. Wiring precautions The quality of the signal wire will affect the quality of the voltage output, it is recommended to use high quality shielded cable. 7.
