Serial GPIO port cannot be opened

Sympton

You are using the GPIO serial port (/dev/serial0 aka /dev/ttyAMA0), and the nodes do not update. If you open the /logs/gateway.sys.log you will see an error message like this:

[02-26-19_13:01:50.144] [ERROR] Cannot open /dev/ttyAMA0

Solution

You need to ensure the hardware GPIO serial port/dev/ttyAMA0 is enabled and not bound by any service. If you run sudo raspi-config and under Interfacing->Serial you should answer No to the “Allow logon over serial console?” question, and Yes to the “Enable GPIO serial port?“. This frees the serial port from being used by the logon service.

Then run sudo nano /boot/config.txt and ensure the GPIO uart is enabled, you should find enable_uart=1 at the end of the file, if not there add it and ensure it is set to “1”.

Also, add this line at the end of the file if not already there: dtoverlay=pi3-disable-bt.

Save and exit editing config.txt with Ctrl-X,Y. Then run this command: sudo systemctl disable hciuart, and finally reboot for all changes to take effect.

To verify the serial port is free for use by the gateway.js software, install and open minicom (assumes 19200 baud on attached Moteino/MightyHat):

sudo apt-get install minicom
sudo minicom -b 19200 -D /dev/ttyAMA0

For reference and more details you may also want to read this helpful blog post that reviews the Pi3’s GPIO serial port and its usage with other hardware. There is also this blog post that discusses serial port issues on the RaspberryPi 3.

I do not receive SMS/emails from events

Symptom

You have enabled events that send text messages or emails, but  you are not receiving them.

Solution

Make sure you visit the settings page where you setup your email, phone number and passwords so that the email application can use your email for this purpose.