如何使用 Grove - PH 传感器套件（E-201C-蓝色）Raspberry pi 零和 GrovePi 零板获得 Java 中的 pH

Question

我有GrovePi Zero（GrovePi0） from GrovePi Zero Base Kit and Grove - PH Sensor Kit (E-201C-Blue) 我在 Raspberry Pi Zerro 2 上使用 Java（我可以使用任何版本的 JDK 8...17）。使用 GrovePi-pi4j 和 Pi4j 版本 1.4（可以使用任何版本）

我的 class 下面的 GrovePHSensor 代表 PH 传感器。

@GroveAnalogPin
public class GrovePHSensor extends GroveAnalogInputDevice<Double> {
   
public GrovePHSensor(GrovePi grovePi, int pin) throws IOException {
    super(grovePi.getAnalogIn(pin, 4));
}

@Override
public Double get(byte[] data) {
 /// WHAT TO DO HERE?
}
}

问题是有大量奇怪的代码给出了不同的结果即使我认为我理解它的作用，我也不确定这样做是否正确。

例如这个线程非常混乱https://forum.dexterindustries.com/t/grove-ph-sensor-kit-e-201c-blue-raspberry-pi-zero/7961/13

同时 wiki 页面在 Seeed https://wiki.seeedstudio.com/Grove-PH-Sensor-kit/ 给出了具有不同公式的 Arduino 的示例代码

当我读取 4 字节[]时，我得到类似 [Pi4J IO read][0, 1, -106, -1] 如果我读取超过 4 个字节，那么末尾的所有字节都是 -1

最好能清楚地实现 public Double get(byte[] data) {} 函数 ...

Answer 1

@GroveAnalogPin
public class GrovePHSensor extends GroveAnalogInputDevice<Double> {
     private static final Logger l = 
     LogManager.getLogger(GrovePHSensor.class.getName());
     /*** pH values range */
     public static final double PH_RANGE = 14.0;
    /*** 
      number of possible samples with 10 bit analog to digital converter 
     */
    public static final int A2D_RANGE = 1023;

public GrovePHSensor(GrovePi grovePi, int pin) throws IOException {
    super(grovePi.getAnalogIn(pin, 4));
}

@Override
public Double get(byte[] data) {
    // the extraction of the value is taken from the sample of the 
    // RotarySensor3Led 
    // https://github.com/DexterInd/GrovePi/blob/master/Software/Java8/GrovePi-spec/src/main/java/org/iot/raspberry/grovepi/devices/GroveRotarySensor.java
    // this is how its is done there

    int[] v = GroveUtil.unsign(data);
    double sensorValue = (v[1] * 256) + v[2];

    // the Analog to Digital is 10 bit -> 1023 intervals that cover the range of pH of 0 to 14
    // hence the pH value is the sensor value that is 0 to 1024
    // times the pH per interval of the A2D 14/1023
    double ph = sensorValue * (PH_RANGE / (double) A2D_RANGE);
    l.trace("sensorValue = {}  ph={}", sensorValue, ph);
    return ph;
    }
}

如何使用 Grove - PH 传感器套件（E-201C-蓝色）Raspberry pi 零和 GrovePi 零板获得 Java 中的 pH

how to get pH in Java using Grove - PH Sensor Kit (E-201C-Blue) Raspberry pi Zero and GrovePi Zero Board

java

raspberry-pi

grovepi+

sensors