Rainbow Electronics DS1721 User Manual

Page 11

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DS1721

11 of 16

Stop Convert T [22h]

This command stops temperature conversion. No further data is required. This command may be used to
halt a DS1721 in continuous conversion mode. After issuing this command, the current temperature
measurement will be completed, stored and the DS1721 will remain idle until a Start Convert T is issued
to resume conversions.

DS1721 COMMAND SET Table 4

INSTRUCTION

DESCRIPTION

PROTOCOL

2-WIRE BUS DATA

AFTER ISSUING

PROTOCOL

NOTES

REGISTER COMMANDS

Access
Configuration

Writes to/Reads from 8-bit
configuration/status register

ACh

1 data byte

1

Access TH

Writes to/Reads from
12-bit TH register

A1h

1 or 2 data bytes

1, 3

Access TL

Writes to/Reads from
12-bit TL register

A2h

1 or 2 data bytes

1, 3

CONVERSION COMMANDS

Start Convert T

Initiates temperature
conversion

51h

idle

2

Stop Convert T

Terminates continuous
conversions

22h

idle

2

Read
Temperature

Reads 12-bit
Temperature register

AAh

Read 1 or 2 data bytes

3

NOTES:

1. Data direction depends upon R/

W

bit in the 2-wire control byte.

2. In continuous conversion mode, a Stop Convert T command will halt continuous conversion. To

restart, the Start Convert T command must be issued. In one-shot mode, a Start Convert T command
must be issued for every temperature reading desired.

3. If the user only desires 8-bit thermometer readings, the master need only read 1 data byte and follow

with a NACK and STOP. If higher resolution is required, 2 bytes must be read.

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