TI中文支持网1294开发板中ADC测量AIN2的电压，应怎么设置函数？急求解答，谢谢。
Susan Yang：
您可以参考tivaware内的相关代码
C:\ti\TivaWare_C_Series-2.1.4.178\examples\peripherals\adc
//***************************************************************************** // // single_ended.c - Example demonstrating how to configure the ADC for //single ended operation. // // Copyright (c) 2010-2017 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 2.1.4.178 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"//***************************************************************************** // //! \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/PE3. //! //! 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 - PE3 //! //! 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. // //*****************************************************************************//***************************************************************************** // // This function sets up UART0 to be used for a console to display information // as the example is running. // //***************************************************************************** void InitConsole(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); }//***************************************************************************** // // 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. // //***************************************************************************** int main(void) { #if defined(TARGET_IS_TM4C129_RA0) ||\defined(TARGET_IS_TM4C129_RA1) ||\defined(TARGET_IS_TM4C129_RA2)uint32_t ui32SysClock; #endif//// 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[1];//// 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.// #if defined(TARGET_IS_TM4C129_RA0) ||\defined(TARGET_IS_TM4C129_RA1) ||\defined(TARGET_IS_TM4C129_RA2)ui32SysClock = SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |SYSCTL_OSC_MAIN |SYSCTL_USE_PLL |SYSCTL_CFG_VCO_480), 20000000); #elseSysCtlClockSet(SYSCTL_SYSDIV_10 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN |SYSCTL_XTAL_16MHZ); #endif//// 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/PE3\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_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_PORTE_BASE, GPIO_PIN_3);//// 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, 3, 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, 3, 0, ADC_CTL_CH0 | ADC_CTL_IE |ADC_CTL_END);//// Since sample sequence 3 is now configured, it must be enabled.//ADCSequenceEnable(ADC0_BASE, 3);//// Clear the interrupt status flag.This is done to make sure the// interrupt flag is cleared before we sample.//ADCIntClear(ADC0_BASE, 3);//// Sample AIN0 forever.Display the value on the console.//while(1){//// Trigger the ADC conversion.//ADCProcessorTrigger(ADC0_BASE, 3);//// Wait for conversion to be completed.//while(!ADCIntStatus(ADC0_BASE, 3, false)){}//// Clear the ADC interrupt flag.//ADCIntClear(ADC0_BASE, 3);//// Read ADC Value.//ADCSequenceDataGet(ADC0_BASE, 3, pui32ADC0Value);//// Display the AIN0 (PE3) 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.// #if defined(TARGET_IS_TM4C129_RA0) ||\defined(TARGET_IS_TM4C129_RA1) ||\defined(TARGET_IS_TM4C129_RA2)SysCtlDelay(ui32SysClock / 12); #elseSysCtlDelay(SysCtlClockGet() / 12); #endif} }
