Adafruit DHT22 385 Benutzerhandbuch
Produktcode
385
Aosong(Guangzhou) Electronics Co.,Ltd
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Tell: +86-020-36380552, +86-020-36042809
Fax: +86-020-36380562
http://www.aosong.com
Email:
Email:
Address: No.56, Renhe Road, Renhe Town, Baiyun District, Guangzhou, China
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Data is comprised of integral and decimal part, the following is the formula for data.
AM2303 send out higher data bit firstly!
AM2303 send out higher data bit firstly!
DATA=8 bit integral RH data+8 bit decimal RH data+8 bit integral T data+8 bit decimal T data+8 bit check-
sum
If the data transmission is right, check-sum should be the last 8 bit of "8 bit integral RH data+8 bit decimal RH
data+8 bit integral T data+8 bit decimal T data".
If the data transmission is right, check-sum should be the last 8 bit of "8 bit integral RH data+8 bit decimal RH
data+8 bit integral T data+8 bit decimal T data".
When MCU send start signal, AM2303 change from low-power-consumption-mode to running-mode. When
MCU finishs sending the start signal, AM2303 will send response signal of 40-bit data that reflect the relative
humidity and temperature information to MCU. Without start signal from MCU, AM2303 will not give response
signal to MCU. One start signal for one time's response data that reflect the relative humidity and temperature
information from AM2303. AM2303 will change to low-power-consumption-mode when data collecting finish if
it don't receive start signal from MCU again.
MCU finishs sending the start signal, AM2303 will send response signal of 40-bit data that reflect the relative
humidity and temperature information to MCU. Without start signal from MCU, AM2303 will not give response
signal to MCU. One start signal for one time's response data that reflect the relative humidity and temperature
information from AM2303. AM2303 will change to low-power-consumption-mode when data collecting finish if
it don't receive start signal from MCU again.
1) Check bellow picture for overall communication process:
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Host computer send out
start signal.
Data transmission finished,
Sensor send out
and RL pull up bus's voltage
response signal.
Output data: 1bit"0"
for next transmission
Pull up and wait
Host's signal
Sensor's signal
Output data: 1bit "1"
response from sensor
Sensor pull down
Pull up voltage and get
bus's voltage
ready for sensor's output.
Single-bus output
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