LPC17xx/40xx DAC example

Detailed Description

Example description
This example shows how to use DAC peripheral with 2 modes: POLLING mode or DMA mode.

The DAC will be initialized with maximum current is 700uA. This allows a maximum update rate of 1Mhz DAC updated values have range from 0 to 0x3FF. AOUT ouput voltage will change from: Vss to VDD. Run and observe AOUT signal by oscilloscope.

The UART is used with a small menu to start and control the program.

Special connection requirements

• Embedded Artists' LPC1788 Developer's Kit:
  
• Embedded Artists' LPC4088 Developer's Kit:
  Connect P026 to oscilloscope to observe the output signal.
  
• LPCXpresso LPC1769:
  Need to connect with base board for using RS232/UART port.
  Connect P026 to oscilloscope to observe the output signal.
  J31, J32 on base board should be closed to hear the sound.

Build procedures:
LPC17xx/40xx example quickstart for Keil uVision4
LPC17xx/40xx example quickstart for IAR EWARM
LPC17xx/40xx example quickstart for Code Red Xpresso

Supported boards and board setup:
Embedded Artists' LPC1788 Developer's Kit
Embedded Artists' LPC4088 Developer's Kit
NXP Xpresso LPC1769 board

Submitting LPCOpen issues:
Community support for LPCOpen

Macros
#define	DATA_SIZE   0x400
#define	DAC_TIMEOUT   0x3FF

Functions
static void	App_DMA_Test (void)
static void	App_Polling_Test (void)
void	DMA_IRQHandler (void)
	DMA interrupt handler sub-routine.
int	main (void)
	Main routine for DAC example.

Variables
static const char	WelcomeMenu []
static const char	SelectMenu []
static const char	DirectionMenu []
static volatile uint8_t	channelTC
static volatile uint8_t	dmaChannelNum
static volatile uint8_t	DAC_Interrupt_Done_Flag
static volatile uint8_t	Interrupt_Continue_Flag
static uint32_t	DMAbuffer

Macro Definition Documentation

#define DAC_TIMEOUT   0x3FF

Definition at line 94 of file dac.c.

#define DATA_SIZE   0x400

Definition at line 76 of file dac.c.

Function Documentation

static void App_DMA_Test ( void  )

static

Definition at line 105 of file dac.c.

static void App_Polling_Test ( void  )

static

Definition at line 160 of file dac.c.

void DMA_IRQHandler

(

void

)

DMA interrupt handler sub-routine.

Returns

Nothing

Definition at line 197 of file dac.c.

int main

(

void

)

Main routine for DAC example.

Main program body.

Returns

Nothing

Definition at line 211 of file dac.c.

Variable Documentation

volatile uint8_t channelTC

static

Definition at line 89 of file dac.c.

volatile uint8_t DAC_Interrupt_Done_Flag

static

Definition at line 90 of file dac.c.

const char DirectionMenu[]

static

Initial value:

=
 "Press \'o\' or \'p\' to change sound frequency\r\n"

Definition at line 85 of file dac.c.

uint32_t DMAbuffer

static

Definition at line 91 of file dac.c.

volatile uint8_t dmaChannelNum

static

Definition at line 89 of file dac.c.

volatile uint8_t Interrupt_Continue_Flag

static

Definition at line 90 of file dac.c.

const char SelectMenu[]

static

Initial value:

=
 "Press number 1-2 to choose DAC running mode:\r\n"
 "\t1: Polling Mode \r\n"
 "\t2: DMA Mode \r\n"

Definition at line 81 of file dac.c.

const char WelcomeMenu[]

static

Initial value:

=
 "Hello NXP Semiconductors \r\n"
 "DAC DEMO \r\n"
 "Press \'c\' to continue or \'x\' to quit\r\n"

Definition at line 77 of file dac.c.