Datasheet

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Note: SLA = I2C address 0xB8. Table CRC parity bit, CRC was 16, the low byte first, high byte。

Return error code: 0x80: not support function code 0x81: Read an illegal address 0x82:

write data beyond the scope

0x83: CRC checksum error 0x84: Write disabled.

8.3 Single bus communication (ONE-WIRE)

8.3.1

Single bus typical circuit

Connection with the AM2320 microprocessor typical application circuit shown in Figure 19.

When single-bus communication mode, after pulling the SDA microprocessor I / O ports are

connected.

Single bus communication Special Instructions:

1. A typical application circuit recommended cable length shorter than 30 meters with a

5.1K pull-up resistor when greater than 30 meters when the pull-up resistor to reduce the actual

situation.

2. 3.3V voltage supply is recommended when the cable length is not greater than 1m.

Otherwise, line drop may cause the sensor communication error.

3. The minimum interval of the read sensor 2S; reading interval is less than 2S, temperature

and humidity might result in denial or communication is unsuccessful and so on.

4. Temperature and humidity values are read out every last measurement result, want to get

real-time data, the need to continuously read twice, repeatedly suggested reading sensor, and each

sensor reading interval greater than 2 seconds to obtain accurate data.

Figure 19: AM2320 single bus typical circuit

8.3.2 Single bus communication protocol

Write Status

0x10

0x0F

Send：(SLA+W)+0x10+0x0F+0x01+0x01+0xF4（Low）+0xB7（High）

Note：Function code + register start address + register number

+ save content+ CRC

Return：0x10+0x0F+0x01+0xB4（Low Byte）+0x35（High Byte）

Note：Function code + number + register start address register+

CRC

Write a user

registers a

0x10

Send：(SLA+W)+0x10+0x10+0x02+0x01+0x02+0xC0+0x92

Return：0x10+0x10+0x02+0xFC+0x04