Dust Sesnor (OPC-N2) Values

Post Reply
enviroandy
Posts: 8
Joined: Mon Apr 03, 2017 1:57 am

Dust Sesnor (OPC-N2) Values

Post by enviroandy » Tue Feb 05, 2019 4:22 am

Hi,

After testing a new dust sensor for our sensor suite, we have noticed the sensor is returning the same values irregardless of the environment. Using the V12 example code and board we are unable to get anything other than PM1:0, PM2.5: 0, PM10:0.0000000019. The sensor itself is running on revision 18.

This is the output log from the example code:

Code: Select all

Particle Matter Sensor example
OPC-N2.SPI Mode
OPC-N2.3V3 to ON
OPC-N2: Check status...ready
OPC-N2.Reading information string
4F 50 43 2D 4E 32 20 46 69 72 6D 77 61 72 65 56 65 72 3D 4F 50 43 2D 30 31 38 2E 32 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 2E 
Information string extracted:
OPC-N2 FirmwareVer=OPC-018.2..............................
OPC-N2.Turning off sensor,3V3 off
OPC-N2.SPI Mode
OPC-N2.3V3 to ON
OPC-N2: Check status...ready
Particle sensor started
OPC-N2.Getting PM with fan on
OPC-N2: Check status...ready
OPC-N2.Setting digital pot...done.
OPC-N2.Getting histogram data...Done
OPC-N2.Getting histogram data...Done
OPC-N2.Setting digital pot...done.
Measure performed
PM 1: 0.0000000000 ug/m3
PM 2.5: 0.0000000000 ug/m3
PM 10: 0.0000000019 ug/m3
OPC-N2.Turning off sensor,3V3 off
OPC-N2.SPI Mode
OPC-N2.3V3 to ON
OPC-N2: Check status...ready
Particle sensor started
OPC-N2.Getting PM with fan on
OPC-N2: Check status...ready
OPC-N2.Setting digital pot...done.
OPC-N2.Getting histogram data...Done
OPC-N2.Getting histogram data...Done
OPC-N2.Setting digital pot...done.
Measure performed
PM 1: 0.0000000000 ug/m3
PM 2.5: 0.0000000000 ug/m3
PM 10: 0.0000000019 ug/m3
OPC-N2.Turning off sensor,3V3 off
OPC-N2.SPI Mode
OPC-N2.3V3 to ON
OPC-N2: Check status...ready
Particle sensor started
OPC-N2.Getting PM with fan on
OPC-N2: Check status...ready
OPC-N2.Setting digital pot...done.
OPC-N2.Getting histogram data...Done
OPC-N2.Getting histogram data...Done
OPC-N2.Setting digital pot...done.
Measure performed
PM 1: 0.0000000000 ug/m3
PM 2.5: 0.0000000000 ug/m3
PM 10: 0.0000000019 ug/m3
OPC-N2.Turning off sensor,3V3 off
OPC-N2.SPI Mode
OPC-N2.3V3 to ON
OPC-N2: Check status...ready
Particle sensor started
OPC-N2.Getting PM with fan on
OPC-N2: Check status...ready
OPC-N2.Setting digital pot...done.
OPC-N2.Getting histogram data...Done
OPC-N2.Getting histogram data...Done
OPC-N2.Setting digital pot...done.
Measure performed
PM 1: 0.0000000000 ug/m3
PM 2.5: 0.0000000000 ug/m3
PM 10: 0.0000000019 ug/m3
OPC-N2.Turning off sensor,3V3 off
OPC-N2.SPI Mode
OPC-N2.3V3 to ON
OPC-N2: Check status...ready
Particle sensor started
OPC-N2.Getting PM with fan on
OPC-N2: Check status...ready
OPC-N2.Setting digital pot...done.
OPC-N2.Getting histogram data...Done
OPC-N2.Getting histogram data...Done
OPC-N2.Setting digital pot...done.
Measure performed
PM 1: 0.0000000000 ug/m3
PM 2.5: 0.0000000000 ug/m3
PM 10: 0.0000000019 ug/m3
OPC-N2.Turning off sensor,3V3 off

Are there any common solutions that we could try?

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: Dust Sesnor (OPC-N2) Values

Post by libelium-dev » Tue Feb 05, 2019 9:50 am

Hi,

What API version did you use to upload the code?

Do you have another cable to connect the sensor to the P&S?

Regards

enviroandy
Posts: 8
Joined: Mon Apr 03, 2017 1:57 am

Re: Dust Sesnor (OPC-N2) Values

Post by enviroandy » Wed Feb 06, 2019 2:01 am

Replacing the cord had no affect on the output of the of the device, and remained the same as before. The Waspmote was also programmed using API V29.

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: Dust Sesnor (OPC-N2) Values

Post by libelium-dev » Wed Feb 06, 2019 11:03 am

Hi,

What is the battery level of the P&S? If the battery is low, the node can't provide the needed current to the node since the current consumption of the PM sensor is very high (250mA).

Also, please to to read the sensor continuously during one hour to check if the PM starts to report data. If it's possible, connect a power supply to the panel solar socket to avoid that the battery level decrease.

Code: Select all

#include <WaspOPC_N2.h>

void setup()
{
  OPC_N2.ON();
}

void loop()
{
  if (OPC_N2.getPM(10000) == 1)
  {
    USB.println(F("Measure performed"));
    USB.print(F("PM 1: "));
    USB.print(OPC_N2._PM1);
    USB.println(F(" ug/m3"));
    USB.print(F("PM 2.5: "));
    USB.print(OPC_N2._PM2_5);
    USB.println(F(" ug/m3"));
    USB.print(F("PM 10: "));
    USB.print(OPC_N2._PM10);
    USB.println(F(" ug/m3"));
  }
  else
  {
    USB.print(F("Error performing the measure."));
  }
}
Regards

enviroandy
Posts: 8
Joined: Mon Apr 03, 2017 1:57 am

Re: Dust Sesnor (OPC-N2) Values

Post by enviroandy » Thu Feb 07, 2019 5:00 am

Looks like the same result after running the device for a constant hour using your supplied code. The battery level is also within spec and is operating correctly (physically checked for airflow into and out of the vents).

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: Dust Sesnor (OPC-N2) Values

Post by libelium-dev » Thu Feb 07, 2019 10:07 am

Hi,

Please check the battery using the following code.

Code: Select all

void setup()
{
  // Open the USB connection
  USB.ON();
}

void loop()
{
  // Show the remaining battery level
  USB.print(F("Battery Level: "));
  USB.print(PWR.getBatteryLevel(),DEC);
  USB.print(F(" %"));
  
  // Show the battery Volts
  USB.print(F(" | Battery (Volts): "));
  USB.print(PWR.getBatteryVolts());
  USB.println(F(" V"));
  
  delay(5000);
}
Regards

enviroandy
Posts: 8
Joined: Mon Apr 03, 2017 1:57 am

Re: Dust Sesnor (OPC-N2) Values

Post by enviroandy » Fri Feb 08, 2019 3:43 am

Hi,

Here is the battery level using the battery we're using to debug the sensor:

Code: Select all

Battery Level: 39 % | Battery (Volts): 3.7290322780 V
Battery Level: 39 % | Battery (Volts): 3.7290322780 V
Battery Level: 39 % | Battery (Volts): 3.7290322780 V
Battery Level: 39 % | Battery (Volts): 3.7290322780 V

libelium-dev
Posts: 27967
Joined: Mon Sep 28, 2009 1:06 pm

Re: Dust Sesnor (OPC-N2) Values

Post by libelium-dev » Fri Feb 08, 2019 2:22 pm

Hi,

Please charge the battery fully and try again. If the device still showing zero values, please fill the RMA form and our tech support team will contact you to solve the issue.
https://www.libelium.com/contact/#rma

Regards

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest