TI中文支持网uint32_t Buffer[1];
/*延时1ms*/
void delay_Nms(int n)
{
int k = 0;
for(k = n;k > 0;k–)
SysCtlDelay(SysCtlClockGet() / 3000);
}
void InitADC()
{
SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC1);
delay_Nms(1);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
delay_Nms(1);
GPIOPinTypeADC(GPIO_PORTD_BASE,GPIO_PIN_2);
delay_Nms(1);
ADCSequenceConfigure(ADC1_BASE, 3, ADC_TRIGGER_PROCESSOR, 0);
delay_Nms(1);
ADCSequenceStepConfigure(ADC1_BASE, 3, 0, ADC_CTL_CH0 | ADC_CTL_IE | ADC_CTL_END);
delay_Nms(1);
ADCReferenceSet(ADC1_BASE, ADC_REF_INT);
delay_Nms(1);
ADCIntEnable(ADC1_BASE,3);
delay_Nms(1);
IntEnable(INT_ADC1SS3_TM4C123);
delay_Nms(1);
IntMasterEnable();
delay_Nms(1);
ADCIntClear(ADC1_BASE,3);
delay_Nms(1);
ADCSequenceEnable(ADC1_BASE,3);
delay_Nms(1);
}
void main(void)
{
SysCtlClockSet(SYSCTL_SYSDIV_10 |SYSCTL_USE_PLL |SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ);delay_Nms(1);
InitADC();
while(1)
{
ADCProcessorTrigger(ADC1_BASE, 3);
while(!ADCIntStatus(ADC1_BASE, 3, false))
{
}
ADCIntClear(ADC1_BASE, 3);
ADCSequenceUnderflowClear(ADC1_BASE,3);
ADCSequenceDataGet(ADC1_BASE, 3, Buffer);
}
}
这样配置后在PD2和GND间加上直流模拟电压,单步调试,却发现无论加不加电压\无论加的电压有何变化,FIFO中读到的值都一直在300(十进制)左右徘徊,
感觉就像是这个待转换的电压完全没有加到ADC上一样,而检测到的看起来像是噪声一样.
于是我在观察列表里查看了Buffer的值和几个寄存器,
发现从头至尾这个信道的UnderFlow标志和InterruptMask标志都是1,
而且,虽然我设置了Vref为内部的3V参考电压,但是这个ADC_CTL_VREF寄存器也是始终显示的0-….请问这些寄存器的值是说明我配置出错了吗?
新学M4,请多指教,求专家~
Michael Sun：
share一个ADC的例子如下。这里采用的中断方式读取，需要在启动文件中把中断向量表里把中断函数加上即可。
//*****************************************************************************//// single_ended.c – Example demonstrating how to configure the ADC for// single ended operation.//// Copyright (c) 2010-2013 Texas Instruments Incorporated. All rights reserved.// Software License Agreement// // 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.// // This is part of revision 1.1 of the Tiva Firmware Development Package.////***************************************************************************** #include <stdbool.h>#include <stdint.h>#include "inc/hw_memmap.h"#include "driverlib/adc.h"#include "driverlib/gpio.h"#include "driverlib/pin_map.h"#include "driverlib/sysctl.h"#include "driverlib/uart.h"#include "utils/uartstdio.h"
#include "driverlib/interrupt.h"
#include "inc/hw_ints.h"#include "inc/hw_types.h"#include "inc/hw_adc.h"
//*****************************************************************************////! \addtogroup adc_examples_list//! <h1>Single Ended ADC (single_ended)</h1>//!//! This example shows how to setup ADC0 as a single ended input and take a//! single sample on AIN0/PE7.//!//! This example uses the following peripherals and I/O signals. You must//! review these and change as needed for your own board://! – ADC0 peripheral//! – GPIO Port E peripheral (for AIN0 pin)//! – AIN0 – PE7//!//! The following UART signals are configured only for displaying console//! messages for this example. These are not required for operation of the//! ADC.//! – UART0 peripheral//! – GPIO Port A peripheral (for UART0 pins)//! – UART0RX – PA0//! – UART0TX – PA1//!//! This example uses the following interrupt handlers. To use this example//! in your own application you must add these interrupt handlers to your//! vector table.//! – None.////*****************************************************************************#define ADCSAMPLERATE_1MSPS 0x7 // 1,000,000 samples per second#define ADCSAMPLERATE_500KSPS 0x5 // 500,000 samples per second#define ADCSAMPLERATE_250KSPS 0x3 // 250,000 samples per second#define ADCSAMPLERATE_125KSPS 0x1 // 125,000 samples per second//*****************************************************************************//// This function sets up UART0 to be used for a console to display information// as the example is running.////*****************************************************************************
uint32_t pui32ADC0Value[8];uint32_t Data[8]={0};uint32_t TempVal = 0;uint32_t TempVal2 = 0;
void ADCSampleRateSet(uint32_t ui32Speed){ // // Set the ADC speed // HWREG(ADC0_BASE + ADC_O_PC) = (ui32Speed);}
uint32_t ADCSampleRateGet(void){ // // Return the current ADC speed. // return((HWREG(ADC0_BASE + ADC_O_PC) & 0x0f));}
voidInitConsole(void){ // // Enable GPIO port A which is used for UART0 pins. // TODO: change this to whichever GPIO port you are using. // SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA); // // Configure the pin muxing for UART0 functions on port A0 and A1. // This step is not necessary if your part does not support pin muxing. // TODO: change this to select the port/pin you are using. // GPIOPinConfigure(GPIO_PA0_U0RX); GPIOPinConfigure(GPIO_PA1_U0TX); // // Enable UART0 so that we can configure the clock. // SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0); // // Use the internal 16MHz oscillator as the UART clock source. // UARTClockSourceSet(UART0_BASE, UART_CLOCK_PIOSC); // // Select the alternate (UART) function for these pins. // TODO: change this to select the port/pin you are using. // GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1); // // Initialize the UART for console I/O. // UARTStdioConfig(0, 115200, 16000000);}
void ADC0Sequence0Isr(void){
uint16_t i; // // Clear the ADC interrupt flag. // ADCIntClear(ADC0_BASE, 0);
// // Read ADC Value. // ADCSequenceDataGet(ADC0_BASE, 0, pui32ADC0Value);
for(i = 0;i < 8;i ++) { Data[i] = pui32ADC0Value[i]*3300/4096; } SysCtlDelay(1);} //*****************************************************************************//// Configure ADC0 for a single-ended input and a single sample. Once the// sample is ready, an interrupt flag will be set. Using a polling method,// the data will be read then displayed on the console via UART0.////*****************************************************************************intmain(void){ // // This array is used for storing the data read from the ADC FIFO. It // must be as large as the FIFO for the sequencer in use. This example // uses sequence 3 which has a FIFO depth of 1. If another sequence // was used with a deeper FIFO, then the array size must be changed. // //uint32_t pui32ADC0Value[8]; //uint32_t Data[8]={0}; // // Set the clocking to run at 20 MHz (200 MHz / 10) using the PLL. When // using the ADC, you must either use the PLL or supply a 16 MHz clock // source. // TODO: The SYSCTL_XTAL_ value must be changed to match the value of the // crystal on your board. // SysCtlClockSet(SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ); // // Set up the serial console to use for displaying messages. This is // just for this example program and is not needed for ADC operation. // InitConsole(); // //// // Display the setup on the console.// // UARTprintf("ADC ->\n"); //UARTprintf(" Type: Single Ended\n"); //UARTprintf(" Samples: One\n"); //UARTprintf(" Update Rate: 250ms\n"); //UARTprintf(" Input Pin: AIN0/PE7\n\n"); // // The ADC0 peripheral must be enabled for use. // SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0); // // For this example ADC0 is used with AIN0 on port E7. // The actual port and pins used may be different on your part, consult // the data sheet for more information. GPIO port E needs to be enabled // so these pins can be used. // TODO: change this to whichever GPIO port you are using. // SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD); SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE); // // Select the analog ADC function for these pins. // Consult the data sheet to see which functions are allocated per pin. // TODO: change this to select the port/pin you are using. // GPIOPinTypeADC(GPIO_PORTD_BASE, GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3); GPIOPinTypeADC(GPIO_PORTE_BASE, GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3);
//set sample rate ADCSampleRateSet(ADCSAMPLERATE_1MSPS);
// // Enable sample sequence 3 with a processor signal trigger. Sequence 3 // will do a single sample when the processor sends a signal to start the // conversion. Each ADC module has 4 programmable sequences, sequence 0 // to sequence 3. This example is arbitrarily using sequence 3. // ADCSequenceConfigure(ADC0_BASE, 0, ADC_TRIGGER_PROCESSOR, 0); // // Configure step 0 on sequence 3. Sample channel 0 (ADC_CTL_CH0) in // single-ended mode (default) and configure the interrupt flag // (ADC_CTL_IE) to be set when the sample is done. Tell the ADC logic // that this is the last conversion on sequence 3 (ADC_CTL_END). Sequence // 3 has only one programmable step. Sequence 1 and 2 have 4 steps, and // sequence 0 has 8 programmable steps. Since we are only doing a single // conversion using sequence 3 we will only configure step 0. For more // information on the ADC sequences and steps, reference the datasheet. // ADCSequenceStepConfigure(ADC0_BASE, 0, 0, ADC_CTL_CH0 );//PE3 ADCSequenceStepConfigure(ADC0_BASE, 0, 1, ADC_CTL_CH1 );//PE2 ADCSequenceStepConfigure(ADC0_BASE, 0, 2, ADC_CTL_CH2 );//PE1 ADCSequenceStepConfigure(ADC0_BASE, 0, 3, ADC_CTL_CH3 );//PE0 ADCSequenceStepConfigure(ADC0_BASE, 0, 4, ADC_CTL_CH4 );//PD3 ADCSequenceStepConfigure(ADC0_BASE, 0, 5, ADC_CTL_CH5 );//PD2 ADCSequenceStepConfigure(ADC0_BASE, 0, 6, ADC_CTL_CH6 );//PD1 ADCSequenceStepConfigure(ADC0_BASE, 0, 7, ADC_CTL_CH7 | ADC_CTL_IE |ADC_CTL_END);
ADCIntEnable(ADC0_BASE, 0); IntEnable(INT_ADC0SS0); IntMasterEnable();
ADCIntClear(ADC0_BASE, 0); // // Since sample sequence 3 is now configured, it must be enabled. // ADCSequenceEnable(ADC0_BASE, 0); // // Clear the interrupt status flag. This is done to make sure the // interrupt flag is cleared before we sample. //
TempVal = ADCSampleRateGet();
// // Sample AIN0 forever. Display the value on the console. // while(1) { // // Trigger the ADC conversion. // ADCProcessorTrigger(ADC0_BASE, 0);
/* // // Wait for conversion to be completed. // while(!ADCIntStatus(ADC0_BASE, 0, false)) { } // // Clear the ADC interrupt flag. // ADCIntClear(ADC0_BASE, 0); // // Read ADC Value. // ADCSequenceDataGet(ADC0_BASE, 0, pui32ADC0Value);
*/ /* Data[0] = pui32ADC0Value[0]*3300/4096; Data[1] = pui32ADC0Value[1]*3300/4096; Data[2] = pui32ADC0Value[2]*3300/4096; Data[3] = pui32ADC0Value[3]*3300/4096; Data[4] = pui32ADC0Value[4]*3300/4096; Data[5] = pui32ADC0Value[5]*3300/4096; Data[6] = pui32ADC0Value[6]*3300/4096; Data[7] = pui32ADC0Value[7]*3300/4096; */ // // Display the AIN0 (PE7) digital value on the console. //// UARTprintf("AIN0 = %4d\r", pui32ADC0Value[0]); // // This function provides a means of generating a constant length // delay. The function delay (in cycles) = 3 * parameter. Delay // 250ms arbitrarily. // SysCtlDelay(SysCtlClockGet() / 12); }}
Tianli Zhang：
回复 Michael Sun:
你好,我曾用过example里的single ended adc代码,控制台初始化那部分就报错,应该是缺少头文件之类的,但是ADC部分都是按例程写的,现在对比了你给的代码,实在是找不出什么代码问题了…
可是这个问题一直都在,FIFO中的数据永远就是那么300多,请问我这样直接把电压加在板子上有没有问题?
测量过两个引脚的电压,和直流源输出的数值是一样的,但是调试时就是没有输入,
而且,设置断点之后用"Resume"运行中断处理程序时存储Get到的FIFO值的那个变量Buffer的值可以随FIFO值变化,但是如果用Step Over 单步运行中断处理程序时FIFO中的值却不能通过
ADCSequenceDataGet(ADC1_BASE, 3, Buffer);
这个函数写入Buffer中
作为一个新手,这些情况让我非常的困惑,跪求个解释
Tianli Zhang：
回复 Michael Sun:
刚刚单步调试的时候发现ADC1SS3的FIFO EMPTY那个标志始终是1…并且这个信道的UnderFlow也一直是1…这种情况应该不太正常…
Tianli Zhang：
回复 Michael Sun:
还有个ADC_IM_MASK标志也是1…配置的是哪个信道那个信道的ADC_IM_MASK就是1…这难道代表这个信道的中断都被屏蔽了吗??
