s5uishida/ppd42ns-driver

a java library that operates dust sensor called PPD42NS

ppd42ns-driver

ppd42ns-driver is a java library that operates dust sensor called PPD42NS to connect PPD42NS to GPIO terminal of Raspberry Pi 3B and make it for use in java. I releases this in the form of the Eclipse plug-in project. You need Java 8 or higher.

I use Pi4J for gpio communication in java and have confirmed that it works in Raspberry Pi 3B (Raspbian Buster Lite OS (2019-07-10)).

Connection of PPD42NS and Raspberry Pi 3B

Connect with Vin <--> Vin,GND <--> GND, PM2.5 <--> Tx. This is also helpful.

• Pins of PPD42NS
  • Vin (pin#3 - Red)
  • GND (pin#1 - Black)
  • PM2.5 (pin#4 - Yellow)
• GPIO of Raspberry Pi 3B
  • Vin --> (2) or (4)
  • GND --> (6), (9), (14), (20), (25), (30), (34) or (39)
  • Tx --> (19) GPIO10, (38) GPIO20 or (8) GPIO14

Install Raspbian Buster Lite OS (2019-07-10)

The reason for using this version is that it is the latest as of July 2019 and BlueZ 5.50 is included from the beginning, and use Bluetooth and serial communication simultaneously.

Configuration of Raspbian Buster Lite OS

• Edit /boot/cmdline.txt

console=serial0,115200 --> removed

• Edit /boot/config.txt

@@ -45,7 +45,7 @@
 # Uncomment some or all of these to enable the optional hardware interfaces
 #dtparam=i2c_arm=on
 #dtparam=i2s=on
-#dtparam=spi=on
+dtparam=spi=on
 
 # Uncomment this to enable the lirc-rpi module
 #dtoverlay=lirc-rpi
@@ -55,6 +55,10 @@
 # Enable audio (loads snd_bcm2835)
 dtparam=audio=on
 
+enable_uart=1
+dtoverlay=pi3-miniuart-bt
+core_freq=250
+
 [pi4]
 # Enable DRM VC4 V3D driver on top of the dispmanx display stack
 dtoverlay=vc4-fkms-v3d

When editing is complete, reboot.

Install WiringPi Native Library

Pi4J depends on the WiringPi native library by Gordon Henderson. The Pi4J native library is dynamically linked to WiringPi.

# apt-get update
# apt-get install wiringpi

When using with Raspberry Pi 4B, install the latest version as follows. Please refer to here.

# wget https://project-downloads.drogon.net/wiringpi-latest.deb
# dpkg -i wiringpi-latest.deb

Please make sure it’s version 2.52.

# gpio -v
gpio version: 2.52

Note. In October 2019, I have not confirmed the official information that can use Raspberry Pi 4B with Pi4J and WiringPi. I've simply checked that it works, but some problems may occur.

Install jdk8 on Raspberry Pi 3B

For example, the installation of OpenJDK 8 is shown below.

# apt-get update
# apt-get install openjdk-8-jdk

Install git

If git is not included, please install it.

# apt-get install git

Use this with the following bundles

• SLF4J 1.7.26
• Pi4J 1.2 (pi4j-core.jar)

I would like to thank the authors of these very useful codes, and all the contributors.

How to use

The following sample code will be helpful. In the following code, ppd42ns.read() takes about 30 seconds to measure.

import com.pi4j.io.gpio.Pin;
import com.pi4j.io.gpio.RaspiPin;

import io.github.s5uishida.iot.device.ppd42ns.driver.PPD42NSDriver;
import io.github.s5uishida.iot.device.ppd42ns.driver.PPD42NSObservationData;

public class MyPPD42NS {
    private static final Logger LOG = LoggerFactory.getLogger(MyPPD42NS.class);
    
    public static void main(String[] args) {
        PPD42NSDriver ppd42ns = PPD42NSDriver.getInstance(RaspiPin.GPIO_10);
        ppd42ns.open();
    
        while (true) {
            try {
                PPD42NSObservationData data = ppd42ns.read();
                LOG.info("[{}] {}", ppd42ns.getName(), data.toString());
            } catch (IOException e) {
                LOG.warn("caught - {}", e.toString());
            }
        }
    
//      if (ppd42ns != null) {
//          ppd42ns.close();
//      }
    }
}