See last page for copyright and document info, File: Reeve_GpsNtp-Pi_Setup.doc, Page 15
6. Install and Verify Pulse Per Second ~ PPS
Install software to support PPS:
sudo apt-get install pps-tools
sudo apt-get install libcap-dev
Configure the RPi to use the general purpose input/output (GPIO) for the PPS input from the GPS receiver:
sudo nano /boot/config.txt
Add a new line as shown below. The value X = 4 or 18 depending on GPS board. The HAB GPS uses GPIO pin 18
and the Adafruit GPS uses GPIO pin 4.
dtoverlay=pps-gpio,gpiopin=X
The PuTTY window should look similar to this (this example shows the pin used with the Adafruit GPS board):
Type CTRL-X (Exit), Y (yes), Enter to save and close the editor.
Additional changes are required to use PPS
sudo nano /etc/modules
Add a new line
pps-gpio
The PuTTY window should look similar to this:
