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standard protocols addressing, can be directly linked to the I C bus (the bus is only allowed to hang

a product), without additional wiring, operation simple. Read AM2321 sensors, strictly in accordance

with the agreement of the two communication methods and timing proceed. Specific details see

single communication protocol and I C bus communication protocol detailed.

8.1 I C standard communication protocol introduced

8.1.1 I

Another form of AM2321 processor and micro controller interface is I C serial bus, in this

brief introduction about the I C bus protocol standards. Due to space limitations, can’t list all the

contents of the agreement deeper questions, please consult the relevant information (refer to the

Philips website access).

8.1.2 I C Bus Overview

Philips (Philips) at 20 years ago invented a simple two-wire bidirectional serial communication

bus, the bus is called the Inter-I C bus. Currently I C bus has become the industry standard

solution for embedded application, is widely used in a variety of professional-based micro controller,

consumer and telecommunications products, as a control, diagnostics and power management bus.

Multiple matches I C bus standard devices can communicate via the same I C bus, without the

need to address decoder.

I

C bus require only the two signal lines, a serial data line SDA, the other is a serial clock

line SCL. I C bus devices generally have their SDA and SCL pins are open-drain (or open collector)

output structure. Therefore, actual use, SDA Figure 4: AM2321 wiring diagram and SCL signal lines

must add pull-up resistors (Rp, Pull-Up Resistor). Value pull-up resistor is generally 3 ~ 10 kΩ.

Therefore, when the bus is idle, the two signal lines remain high, almost no current consumption;

electrical compatibility, and supports a variety of different voltage logic device interfaces; may be

directly connected between the two buses, not require additional conversion circuitry to support a

variety of communication more from a major is the most common means of communication. It also

supports dual-host communication, multi

host communication and broadcast mode, etc.

I C typical configuration shown in Figure 5.

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