General Purpose A/D - Motorola G24 Developer's Manual

General Purpose A/D

The G24 provides 3 general purpose A/D (GPAD) signals for customer application use. Each
A/D signal can monitor a separate external voltage and report its measured level independently to
the application, through the AT command interface.
The GPAD signals can sense a DC voltage level of 0 - 2.3 V, which is converted internally to a
10-bit digital value. The A/D input is sampled 8 consecutive times for each measurement, and the
8 samples are compared and averaged to provide a stable and valid result.
The A/D signals operation and reporting mechanism is defined by the AT+MMAD command.
Each A/D can be defined to provide several reports:
•
A single measurement.
A single A/D measurement will take place and will be reported upon activation of the AT
command.
•
An automatic periodical measurement.
The A/D measures its input signal at a rate that is defined by the user application. Every
measurement will generate an unsolicited message over the serial interface.
Important:
•
An automatic periodical measurement with predefined limits.
The A/D measures its input signal at a rate that is defined by the user. The user also defines
upper and/or lower limits for the A/D measurements. Each measurement is compared to
these limits, and an unsolicited message is generated only if these limits are exceeded.
Important:
Table 2-19
January 1, 2006
In case the defined periodical measurement rate is equal to, or shorter than, the
defined sleep mode delay settings (ATS24), G24 will not enter low power mode.
In case the defined periodical measurement rate is equal to, or shorter than, the
defined sleep mode delay settings (ATS24), G24 will not enter low power mode.
gives the GPAD specifications.
Table 2-19: GPAD Specifications
Parameter Conditions
Maximum Operating range
Input Voltage
Input Voltage Dynamic range
Sampling 8 consecutive
Time samples
Resolution
Module Hardware Description
Chapter 2: Hardware Interface Description
Min Typ Max Unit
-0.1 2.75 V
2.3 V
100 µS
10 mV
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