5.16 Digital to Analogue Converter – DAC

Pin

 

Name

 

Direction

 

Function

 

 

 

 

 

 

 

20

 

DAC

 

Output

 

Pulse width modulated signal

The GPIOx has dual functionality. In addition of being a fully programmable GPIO it also has the capability of becoming a PWM output. This PWM can be used as a DAC by implementing an RC-filter followed by an optional buffer.

Figure 5.16-1 Typical arrangement for adapting PWM for a DAC function

5.17 Analogue to Digital Converters (ADIN1, ADIN2, ADIN3, ADIN4)

Pin

 

Name

 

Direction

 

Function

 

 

 

 

 

 

 

26

 

ADIN1

 

Input

 

ADC Input 1

27

 

ADIN2

 

Input

 

ADC Input 2

28

 

ADIN3

 

Input

 

ADC Input 3

13

 

ADIN4

 

Input

 

ADC Input 4/GPIO5

ADC pins is converted and stored in a register inside the wireless modem. When the appropriate AT command is received by the wireless modem, the digital value stored in the register is read.

The module has a single precision 10-bit ADC, shared by a number of functions within the module and also through the external interface connections (three dedicated, one shared). The ADC sharing arrangement is shown below.

LZT 123 1834

67