+***** Disable Bluetooth
+In order to reduce power consumed by bluetooth transmissions,
+bluetooth functionality should be disabled (see [[https://di-marco.net/blog/it/2020-04-18-tips-disabling_bluetooth_on_raspberry_pi/][link]]).
+
+Modify the ~/boot/config.txt~ file (the Pi's equivalent to BIOS
+settings; see [[https://www.raspberrypi.org/documentation/configuration/config-txt/][link]]) to make sure the following lines are added:
+
+#+BEGIN_EXAMPLE
+# Disable Bluetooth
+dtoverlay=disable-bt
+#+END_EXAMPLE
+
+The ~hciuart~ service is associated with bluetooth functionality via
+UART which may conflict with location and time data provided via
+~/dev/ttyAMA0~. It should be disabled like so:
+
+#+BEGIN_EXAMPLE
+$ sudo systemctl disable hciuart
+#+END_EXAMPLE
+
+***** Disable login console via serial port
+Some ~ninfacyzga~ functions (location and time) require data transfer
+via ~/dev/ttyAMA0~. In order to prevent serial login programs from
+interfering with such functions, it is necessary to disable them.
+
+Run the following commands to disable login via ~ttyAMA0~:
+
+#+BEGIN_EXAMPLE
+$ sudo systemctl stop serial-getty@ttyAMA0.service
+$ sudo systemctl disable serial-getty@ttyAMA0.service
+$ sudo systemctl disable hciuart
+#+END_EXAMPLE
+
+Modify ~/boot/cmdline.txt~ to remove the console:
+
+#+BEGIN_EXAMPLE
+$ sudo nano /boot/cmdline.txt
+#+END_EXAMPLE
+
+Remove ~console=serial0,115200~
+