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ESP8266-异步达拉斯温度-异常(28)

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Trigary · 技术社区 · 8 年前

我正在计时器中断中启动温度测量(传感器。请求温度),我需要一种方法来知道它是否准备好。我试着使用传感器。isConversionAvailable方法,但它引发了一个异常。我查看了isConversionAvailable方法的源代码,并尝试自己调用readScratchPad方法,结果抛出了一个异常。

完整代码:

#include <DallasTemperature.h>
#include <OneWire.h>

#define TIMER_SECONDS 1
#define SENSOR_PIN 5
OneWire sensorWire(SENSOR_PIN);
DallasTemperature sensors(&sensorWire);

void setup() {
    Serial.begin(115200);
    Serial.println("Initializing...");

    sensors.begin();
    sensors.setResolution(10);
    sensors.setWaitForConversion(false);

    timer1_isr_init();
    timer1_attachInterrupt([] {
        sensors.requestTemperatures();
    });
    timer1_enable(TIM_DIV265, TIM_EDGE, TIM_LOOP);
    timer1_write(F_CPU / 256 * TIMER_SECONDS);

    Serial.println("Initialization complete");
}

void loop() {
    Serial.println("Started the loop method");

    //When this block is uncommented, the second exception is thrown
    /*uint8_t number;
    sensors.readScratchPad(0, &number);
    Serial.print("Scratch pad number: ");
    Serial.println(number);*/

    if (sensors.isConversionAvailable(0)) {
        Serial.print("Temperature: ");
        Serial.println(sensors.getTempCByIndex(0));
    } else {
        Serial.println("The conversion is unavailable");
    }

    Serial.println("Finished the loop method");
}

异常(isConversionAvailable):

Initializing...
Initialization complete
Started the loop method

Exception (28):
epc1=0x402025af epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000000 depc=0x00000000

ctx: cont 
sp: 3ffef230 end: 3ffef460 offset: 01a0

>>>stack>>>
3ffef3d0:  00000000 3ffee354 00000000 402025ad  
3ffef3e0:  3ffef420 00000000 3ffee338 40201e57  
3ffef3f0:  00000000 00000017 3ffef4a0 40202bcd  
3ffef400:  3ffe8588 00000000 3ffef4a0 3ffee42c  
3ffef410:  3fffdad0 3ffee338 3ffef4a0 40202144  
3ffef420:  40201052 88011627 3ffef4a0 40202c1c  
3ffef430:  3fffdad0 00000000 3ffef4a0 40201d0e  
3ffef440:  feefeffe 00000000 3ffee424 40202888  
3ffef450:  feefeffe feefeffe 3ffee440 40100114  
<<<stack<<<

ets Jan  8 2013,rst cause:2, boot mode:(1,6)

异常(readScratchPad):

Initializing...
Initialization complete
Started the loop method

Exception (28):
epc1=0x402025cf epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000000 depc=0x00000000

ctx: cont 
sp: 3ffef250 end: 3ffef470 offset: 01a0

>>>stack>>>
3ffef3f0:  00000000 3ffee364 00000000 402025cd  
3ffef400:  3ffef440 00000000 3ffee348 40201e77  
3ffef410:  00000000 3ffee348 3ffef4b0 40202c18  
3ffef420:  3ffe8438 00000000 3ffef4b0 3ffee43c  
3ffef430:  3fffdad0 3ffee348 3ffef4b0 40201d14  
3ffef440:  3fffdad0 3ffee348 3ffef4b0 40201cd0  
3ffef450:  feefeffe 00000000 3ffee434 402028a8  
3ffef460:  feefeffe feefeffe 3ffee450 40100114  
<<<stack<<<

ets Jan  8 2013,rst cause:2, boot mode:(1,6)

1 回复 | 直到 8 年前

Maximilian Gerhardt 8 年前

查看函数的代码(省略一些注释):

bool DallasTemperature::readScratchPad(const uint8_t* deviceAddress, uint8_t* scratchPad){

    // send the reset command and fail fast
    int b = _wire->reset();
    if (b == 0) return false;

    _wire->select(deviceAddress);
    _wire->write(READSCRATCH);

    for(uint8_t i = 0; i < 9; i++){
        scratchPad[i] = _wire->read();
    }

    b = _wire->reset();
    return (b == 1);
}

sensors.readScratchPad(0, &number);

然后 deviceAddress = NULL _wire->select(deviceAddress) _wire 对象的类型为 OneWire* . 函数 select

void OneWire::select(const uint8_t rom[8])
{
    uint8_t i;

    write(0x55);           // Choose ROM

    for (i = 0; i < 8; i++) write(rom[i]);
}

并且在 rom[i] 您在 NULL 您最初给出的指针。一、 e.:撞车。

deviceAddress 指针。

float DallasTemperature::getTempCByIndex(uint8_t deviceIndex){

    DeviceAddress deviceAddress;
    if (!getAddress(deviceAddress, deviceIndex)){
        return DEVICE_DISCONNECTED_C;
    }
    return getTempC((uint8_t*)deviceAddress);
}

因此,如果您需要第一个传感器的地址,可以通过以下操作获得:

 DeviceAddress deviceAddress;
 if (!sensors.getAddress(deviceAddress, 0)){
     Serial.println("No device address found for index 0!!!");
     return;
 }
 //use deviceAddr in the next call
 ScratchPad readScratchPad; //this is a typedef to uint8_t[9]
 sensors.readScratchPad( (uint8_t*)deviceAddress, readScratchPad);
 //do whatever you like with the values in the readScratchPad array..