User's Manual

HC864-AUTO Hardware User Guide
1vv0300946 Rev.4 – 2012-12-27
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Reserved. Page 59 of 77
12. DAC and ADC section
12.1. DAC Converter
12.1.1. Description
The HC864-AUTO module provides a Digital to Analog Converter. The signal (named
DAC_OUT) is available on pin 40 of the HC864-AUTO module and on pin 17 of PL102 on
EVK2 Board (CS1203).
The on board DAC is in the range from 0 to 1023.
However, an external low-pass filter is necessary.
Min Max Units
Voltage range (filtered) 0 1.8 Volt
Range 0 1023 Steps
The precision is 1023 steps, so if we consider that the maximum voltage is 2V, the integrated
voltage could be calculated with the following formula:
Integrated output voltage = 2 * value / 1023
DAC_OUT line must be integrated (for example with a low band pass filter) in order to obtain
an analog voltage.
12.1.2. Enabling DAC
An AT command is available to use the DAC function.
The command is:AT#DAC[=<enable>[,<value>]]
<value> - scale factor of the integrated output voltage (0..1023 - 10 bit precision)
it must be present if <enable>=1
Refer to SW User Guide or AT Commands Reference Guide for the full description of this
function.
NOTE:
The DAC frequency is selected internally. D/A converter must not be used during
POWERSAVING.