tm4c123 内部温度测量问题

还是使用不当的问题，看看官方的例程，实际测试没有太大波动

//                        sensor.
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// 
// 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
    }
}

PLL时钟参考频率必须在范围5 MHz 到 25 MHz 之间，你的这个4M的频率能倍频起来才怪了。

我没有使用PLL 我是外部16m晶振分频到4m

SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN | SYSCTL_XTAL_16MHZ);    //clk = 4MZ

你试着主频配置为通用的80Mhz试试，老实说，降频使用，还真没试过。

请问这个程序适合TM4C1294板子吗

大同小异吧，可能某个函数会有出入的地方，对照着库函数修改下就好了。

嗯嗯，谢谢，小白还有一个问题， 采样序列的采样数是8，这8具体是什么意思呢，是同时对8个通道采样？还是依次对1个通道进行8次采样?看了论坛上的一些说法，感觉还是不太明白，能不能赐教一下？

你指的是哪个函数的哪个参数呢，这个8应该是adc的通道

采样序列发生器0（Sample Sequencer0）的采样数是8，就是ADCSequenceStepConfigure函数的ui32Step参数，是同时对8个通道采样？还是依次对1个通道进行8次采样?非常感谢！

請問一下高手們，何謂使用不當?

实际测试了下，我的理解是，采样序列发生器0可以采样8次，这个8是进行第八次采样，是对    ADCSequenceStepConfigure(ADC0_BASE, 1, 0, ADC_CTL_TS);

这个函数第四个参数选择的通道进行采样，读取采样序列发生器0的第八次采样值，是这个通道的采样值。

嗯嗯，谢谢！