新建了工程,已经可以控制GPIO31和GPIO34的灯开关,但写入官方历程buffdac_sine_cpu01,DACOUTA(launchpad上30引脚)接示波器,并没有信号产生,我想知道是什么问题?这个官方历程需要改动什么吗?
历程如下
/###########################################################################
//
// FILE: buffdac_enable_cpu01.c
//
// TITLE: Buffered DAC Enable Output Example for F2837xD.
//
//! \addtogroup cpu01_example_list
//! <h1> Buffered DAC Enable (buffdac_enable) </h1>
//!
//! This example generates a voltage on the buffered DAC output,
//! DACOUTA/ADCINA0 (HSEC Pin 9) and uses the default DAC reference setting
//! of VDAC.
//!
//! When the DAC reference is set to VDAC, an external reference voltage
//! must be applied to the VDAC pin. This can accomplished by connecting a
//! jumper wire from 3.3V to ADCINB0 (HSEC pin 12).
//!
//
//###########################################################################
// $TI Release: F2837xD Support Library v3.05.00.00 $
// $Release Date: Thu Oct 18 15:48:42 CDT 2018 $
// $Copyright:
// Copyright (C) 2013-2018 Texas Instruments Incorporated - http://www.ti.com/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the
// distribution.
//
// Neither the name of Texas Instruments Incorporated nor the names of
// its contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// $
//###########################################################################
//
// Included Files
//
#include "F28x_Project.h"
//
// Globals
//
volatile struct DAC_REGS* DAC_PTR[4] = {0x0,&DacaRegs,&DacbRegs,&DaccRegs};
Uint16 dacval = 2048;
//
// Defines
//
#define REFERENCE_VDAC 0
#define REFERENCE_VREF 1
#define DACA 1
#define DACB 2
#define DACC 3
#define REFERENCE REFERENCE_VDAC
#define DAC_NUM DACA
//
// Function Prototypes
//
void configureDAC(Uint16 dac_num);
void main(void)
{
//
// Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the F2837xD_SysCtrl.c file.
//
InitSysCtrl();
//
// Disable CPU interrupts
//
DINT;
//
// Initialize the PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags are cleared.
// This function is found in the F2837xD_PieCtrl.c file.
//
InitPieCtrl();
//
// Clear all interrupts and initialize PIE vector table:
//
IER = 0x0000;
IFR = 0x0000;
InitPieVectTable();
//
// Configure DAC
//
configureDAC(DAC_NUM);
while(1)
{
DAC_PTR[DAC_NUM]->DACVALS.all = dacval;
DELAY_US(2);
}
}
//
// configureDAC - Configure specified DAC output
//
void configureDAC(Uint16 dac_num)
{
EALLOW;
DAC_PTR[dac_num]->DACCTL.bit.DACREFSEL = REFERENCE;
DAC_PTR[dac_num]->DACOUTEN.bit.DACOUTEN = 1;
DAC_PTR[dac_num]->DACVALS.all = 0;
DELAY_US(10); // Delay for buffered DAC to power up
EDIS;
}
//
// End of file
//
