Digital humidity and temperature sensor-AM2305 AOSONG
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Your specialist in innovating humidity & temperature sensors Digital relative humidity & temperature sensor AM2305 1. Feature & Application: *High precision *Outstanding long-term stability *Capacitive type *Extra components not needed *Full range temperature compensated *Long transmission distance, up to 100 meters *Relative humidity and temperature measurement *Low power consumption *Calibrated digital signal *Three-core shielded cable as outgoing line 2. Description: AM2305 output calibrated digital signal. It applys exclusive digital-signal-collecting-technique and humidity sensing technology, assuring its reliability and stability. Its sensing elements is connected with 8-bit single-chip computer. Every sensor of this model is temperature compensated and calibrated in accurate calibration chamber and the calibration-coefficient is saved in type of programme in OTP memory, when the sensor is detecting, it will cite coefficient from memory. Small size & low consumption & long transmission distance(100m) enable AM2305 to be suited in all kinds of harsh application occasions. 3. Technical Specification: Model AM2305 Power supply 3.3-5.5V DC Output signal digital signal via Aosong 1-wire bus Sensing element for RH Polymer humidity capacitor Sensing element for T Apply Dallas DS18B20 for detecting temperature Operating range humidity 0-100%RH; temperature -40~80Celsius Accuracy humidity +-2%RH(Max +-5%RH); temperature +-0.3Celsius Resolution or sensitivity Repeatability Humidity hysteresis Long-term Stability http://www.aosong.com Thomas Liu (Sales Manager) Email: thomasliu198518@aliyun.com , sales@aosong.com

Your specialist in innovating humidity A temperature sensors fully interchangeable 5. Electrical connection diagram: *Three-core shielded cable as outgoing line, the three cores are red wire, yellow wire, black wire. Rp is pull up resistor, when transmisstion distance beyond Power's voltage should be 3.3-5.5V DC. When power is supplied to sensor, don't send any instruction to the sensor within one second to pass unstable status. One capacitor valued lOOnF can be added between VDD and GND for wave filtering. Aosong 1-wire bus is used for communication between MCU and AM2305. ( Aosong 1-wire...

Your specialist in innovating humidity A temperature sensors DATA=16 bits RH data+16 bits Temperature data+8 bits check-sum Example: MCU has received 40 bits data from AM2305 as 16 bits RH data 16 bits T data checksum Here we convert 16 bits RH data from binary system to decimal system, Binary system Decimal system Here we convert 16 bits T data from binary system to decimal system, Binary system Decimal system When highest bit of temperature is 1, it means the temperature is below 0 degree Celsius. Check-sum=the last 8 bits of Sum=1110 1110 When MCU send start signal, AM2305 change from...

Your specialist in innovating humidity & temperature sensors -----------------------------------------------------------------------------------------------------------------------------------1) Step 1: MCU send out start signal to AM2305 and AM2305 send response signal to MCU Data-bus's free status is high voltage level. When communication between MCU and AM2305 begins, MCU will pull low data-bus and this process must beyond at least 1~10ms to ensure AM2305 could detect MCU's signal, then MCU will pulls up and wait 20-40us for AM2305's response. When AM2305 detect the start signal, AM2305...

Your specialist in innovating humidity A temperature sensors Sensor outputs 1 bit data of" 1 " Start transmit 1 bit data Start transmit next 1 bit data Host's signal Sensor's signal If signal from AM2305 is always high-voltage-level, it means AM2305 is not working properly, please check the electrical connection status. 8. Error and sources of error: Measure values maybe influenced by follow factors: Humidity errors Equilibration time too short, steam, water sprays, dripping water or condensation at the sensor, etc. Temperature errors Equilibration time too short, cold or hot outside wall,...

Your specialist in innovating humidity & temperature sensors Relative humidity strongly depend on temperature, that is why we use temperature compensation technology to ensure accurate measurement of RH. But it's still be much better to keep the sensor at same temperature when sensing. AM2305 should be mounted at the place as far as possible from parts that may cause change to temperature. (5) Attentions to light Long time exposure to strong light and ultraviolet may debase AM2305's performance. (6) Attentions to connection wires The connection wires' quality will effect communication's...