Troubleshooting Q&A

R- What do I do if my sensor stops communicating?

1. Check the battery

If you have your sensors communicating to PrivateEyePi you can check the battery status on the dashboard by doing a mouse over on the battery indicator. You will see the last time the battery voltage was recorded as well as the last known voltage. If the value is below 2.2V then a new battery is required.

2. Check distance between sensor and receiver

Reduce the distance between the sensor and the receicver to see if that resolved the issue. Do not put the sensor within 5 feet of the receiver because that will result in lost messages.

3. Do a communication check

The best way to perform a communications check is to using the serial monitor ( Open up a terminal windows on you Raspberry Pi and go to the rf_tools directory you created during the IoT Gateway install:

cd ~
cd rf_tools
sudo wget
python 9600

Move the problematic sensor within line of sight of the base station and either wait for a tramission to occur or force a transmission by opening closing the switch (for rf switch) or removing and re-inserting the battery (see "Why doesn't my sensor restart when I remove and re-insert the battery" below too).

When the sensor starts up you should see:

And then depending on the tyype of the sensor you will see sensor data being trasmitted (e.g. aXXTMPA23.40 or aXXBUTTONON, aXXAWAKE, aXXSLEEPING)

Now move the sensor further away repeating this test.

- What if I am seeing a flood of "STARTED" messages in serial_mon?

1. The most likely cause of this is a low battery from one of your sensors. When the battery runs low this causes the device to restart continuously because it is unable to maintain a charge to stay alive.


- What do I do if I have lost contact with my IOT Gateway

1. This is most frequently caused by a configuratiuon sent to the gateway (e.g. CHDEVID which changes the device ID). You can fix this by resetting your IoT Gateway back to factory setting using the RESET command:

python RESET -V


- Why doesn't my sensor restart when I remove and re-insert the battery?

1. The sensors have a capacitor that can retain a charge that keeps the sensor alive. Removing the battery does not discharge the capacitor. You can safely discharge the capacitor by removing the battery and then shorting the 3V and GND marked pads. Alternately you can remove the battery and wait a few minutes for the capacitor to discharge naturally.

- My IoT Gateway does not appear to be working

  1. Run and power up a sensor (making sure the sensor is more than 3 feet away from the gateway). If you see STARTED messages then the Gateway is likely working. 
  2. Make sure you have configured the serial port correctly
  3. Check if there are multiple applications using the serial port. Only one application can use the serial port at a time. Do a "ps ax" and look for other programs like or using the serial port. You can kill background processes using the "sudo kill [pid]" command. If you have a cron job configured to autostart then disable the cron job (sudo service cron stop). 
  4. Check the serial port is installed (dir /dev) and look for the ttyAMA0 port. If it is not installed then revert back to the serial port configuration in point 1 above. 
  5. Do a loopback test to test if the port is working