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Illustration of MaxDetect 1-wire bus:

DATA=16 bits RH data+16 bits Temperature data+8 bits check-sum

Example: MCU has received 40 bits data from RHT02 as

0000 0010 1000 1100

0000 0001 0101 1111

1110 1110

16 bits RH data

16 bits T data

check sum

Here we convert 16 bits RH data from binary system to decimal system,

0000 0010 1000 1100 → 652

Binary system

Decimal system

RH=652/10=65.2%RH

Here we convert 16 bits T data from binary system to decimal system,

0000 0001 0101 1111 → 351

Binary system

Decimal system

T=351/10=35.1℃

When highest bit of temperature is 1, it means the temperature is below 0 degree Celsius.

16 bits T data

Sum=0000 0010+1000 1100+0000 0001+0101 1111=1110 1110

Check-sum=the last 8 bits of Sum=1110 1110

When MCU send start signal, RHT02 change from standby-status to running-status. When MCU finishs sending

the start signal, RHT02 will send response signal of 40-bit data that reflect the relative humidity and temperature

to MCU. Without start signal from MCU, RHT02 will not give response signal to MCU. One start signal for one

response data from RHT02 that reflect the relative humidity and temperature. RHT02 will change to standby

status when data collecting finished if it don't receive start signal from MCU again.

See below figure for overall communication process, the interval of whole process must beyond 2 seconds.