Elsys ERS CO2 & MORE (LoRaWAN) Sensor

Elsys ERS CO2
For US LoRa bands make sure to select the US902-928 channel.

Highlights
This sensor is advertised as a CO2 sensor when it is much, much more including indoor temperature, humidity, light, motion, and CO2 levels.

  • Storage & Operation Temperatures & Humidity
    • 0 to 40 °C
    • 0 to 85 % RH (non-condensing)
  • CO2 range: 0 – 2000 ppm
  • Substantial documentation provided by the manufacturer, with even more here
  • has NFC or Near Field Communication and it’s pretty neat to work with
  • Requires an in-range LoRa Gateway

Sensors appear in this format in BMON

Sensor ID format
[sensorid]_motion motion sensor, pir
[sensorid]_light light sensor, lux
[sensorid]_co2 internal CO2 sensor, ppm
[sensorid]_Hum_SHT internal humidity sensor, percentage
[sensorid]_temperature internal temperature sensor, degrees C
[sensorid]_rssi received signal strength indication (RSSI)
[sensorid]_snr signal to noise ratio (SNR)
[sensorid]_vdd battery voltage, mV

Notes

  • Use a simple transform if you need to record your data in Degrees F. Remember, this is not a calculated field.

    • You may also use one to convert mV to V if you are monitoring batteries
  • The Elsys ERS CO2 sensor contains an internal supercapacitor capable of maintaining the sensor for hours before finally powering down completely - even after you’ve removed the batteries.

    • This is important because it voids the whole “take the batteries out, wait a few, put them back in” approach we all know and love when it comes to resetting devices quickly.
      • On a more positive note, at least it’s capable of remembering its settings and performing for a bit after the batteries have been removed or have died.

Using NFC to say "Hello"

I attempted to move an Elsys ERS CO2 sensor from one gateway to another and could not get the device to disconnect from the old gateway and reconnect with the new so I reached out to Elsys support, nice people by the way, and was advised of a few things that are worth noting even if you don’t have to use NFC to talk to the device

  • The Elsys ERS CO2 sensor contains an internal supercapacitor capable of maintaining the sensor for hours before finally powering down completely - even after you’ve removed the batteries.
    • This is important because it voids the whole “take the batteries out, wait a few, put them back in” approach we all know and love when it comes to resetting devices quickly.
      • On a more positive note, at least it’s capable of remembering its settings and performing for a bit after the batteries have been removed or have died.

If you don’t have the time to leave the supercapacitor to drain but you need the device to reset itself or rejoin a network you can use NFC to do it. First, check out the ERSCO2 manual and take a look at the NFC Configuration section to familiarize yourself with the the general idea.

Here was my basic approach to write “hello” to the ERSCO2 in order to force a reboot so it would attempt to join my network appropriately. This assumes you have an NFC capable device and an app to pass communications via NFC, NFC Tools for iPhone is the one I’ve used. Elsys provides documentation on an app for Android users. That information is included in the Elsys ERSCO2 manual though my initial testing with it was that it did not work.

Note:

  • Make sure the sensor has adequate batteries before beginning.
  • Must be within touching distance of the Elsys CO2 sensor
  1. Open the NFC Tools App
  2. Click Read
  3. Move your phone/reader near the face of the Elsys CO2 sensor as if you were scanning the device with a metal detection wand
    nfcantenna
  4. Review the record, verify the device is writable
    IMG_0248
  5. Return back to the NFC Tools main screen and click write
  6. Click Add a record
    IMG_0250
  7. Select Text
  8. Type hello in the text box, then press OK
    IMG_0252
  9. Note that the text file is now ready to write and click Write
    IMG_0253
  10. Go to TTN and check the device link time, it should be close to current time.