能不能告诉我原因，照片在附件处
应该是官方的算法不对，你看看这个例程，是没问题的。
// sensor.
//
// 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>ADC Temperature Sensor (temperature_sensor)</h1>
//!
//! This example shows how to setup ADC0 to read the internal temperature
//! sensor.
//!
//! NOTE: The internal temperature sensor is not calibrated. This example
//! just takes the raw temperature sensor sample and converts it using the
//! equation found in the LM3S9B96 datasheet.
//!
//! This example uses the following peripherals and I/O signals. You must
//! review these and change as needed for your own board:
//! - ADC0 peripheral
//!
//! 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);
}
int main(void)
{
uint32_t ui32ADC0Value[4];
volatile uint32_t ui32TempAvg;
volatile uint32_t ui32TempValueC;
volatile uint32_t ui32TempValueF;
SysCtlClockSet(SYSCTL_SYSDIV_5|SYSCTL_USE_PLL|SYSCTL_OSC_MAIN|SYSCTL_XTAL_16MHZ);
InitConsole();
//
// Display the setup on the console.
//
UARTprintf("ADC ->\n");
UARTprintf(" Type: Internal Temperature Sensor\n");
UARTprintf(" Samples: One\n");
UARTprintf(" Update Rate: 250ms\n");
UARTprintf(" Input Pin: Internal temperature sensor\n\n");
//5分频，使用PLL，外部晶振16M，system时钟源选择 main osc。系统时钟40MHZ
SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0);
//使能ADC0
ADCSequenceConfigure(ADC0_BASE, 1, ADC_TRIGGER_PROCESSOR, 0);
//We want to use ADC0, sample sequencer 1,
//we want the processor to trigger the sequence and we want to use the highest priority
ADCSequenceStepConfigure(ADC0_BASE, 1, 0, ADC_CTL_TS);
ADCSequenceStepConfigure(ADC0_BASE, 1, 1, ADC_CTL_TS);
ADCSequenceStepConfigure(ADC0_BASE, 1, 2, ADC_CTL_TS);
//Configure steps 0 - 2 on sequencer 1 to sample the temperature sensor (ADC_CTL_TS).
ADCSequenceStepConfigure(ADC0_BASE,1,3,ADC_CTL_TS|ADC_CTL_IE|ADC_CTL_END);
//Sample the temperature sensor (ADC_CTL_TS) and configure the interrupt flag (ADC_CTL_IE)
//Tell the ADC logic that this is the last conversion on sequencer1 (ADC_CTL_END).
ADCSequenceEnable(ADC0_BASE, 1);
//enable ADC sequencer 1
while(1)
{
ADCIntClear(ADC0_BASE, 1);
ADCProcessorTrigger(ADC0_BASE, 1);
//trigger the ADC conversion with software
while(!ADCIntStatus(ADC0_BASE, 1, false))
{
}
//wait for the conversion to complete
ADCSequenceDataGet(ADC0_BASE, 1, ui32ADC0Value);
ui32TempAvg = (ui32ADC0Value[0] + ui32ADC0Value[1] + ui32ADC0Value[2] + ui32ADC0Value[3] + 2)/4;
//Since 2/4 = 1/2 = 0.5, 1.5 will be rounded to 2.0 with
//the addition of 0.5. In the case of 1.0, when 0.5 is added to yield 1.5, this will be rounded
//back down to 1.0 due to the rules of integer math.即四舍五入
ui32TempValueC = (1475 - ((2475 * ui32TempAvg)) / 4096)/10;
//TEMP = 147.5 – ((75 * (VREFP – VREFN) * ADCVALUE) / 4096)
//VREFP – VREFN=3.3V
ui32TempValueF = ((ui32TempValueC * 9) + 160) / 5;
UARTprintf("Temperature = %d*C or %d*F\r\n", ui32TempValueC,
ui32TempValueF);
//F = ( C * 9)/5 +32
}
}
