Non-comprehensive parts list:
Still a work in progress.
The hardest part about this project was selecting a USB soundcard that worked. Ultimately I found one I got on ebay for $1 10 years ago and it worked better than the 3 others I tried.
I’ve included some config options for PPS, even though I am not using PPS at this time.
Disable serial console
In /boot/cmdline.txt remove console=ttyAMA0,115200 or console=ttyS0,115200 depending on Pi 2 or 3
Enable UART and map PPS
# needed for hardware uart enable_uart=1 dtoverlay=pps-gpio,gpiopin=18
Install needed packages
apt install libgps-dev gpsd git libasound2-dev gpsd-clients pps-tools
Disable systemd gpsd
systemctl stop gpsd.socket systemctl disable gpsd.socket
git clone https://github.com/wb2osz/direwolf.git cd direwolf make make install mkdir /etc/direwolf mv ~/direwolfconfigs /etc/direwolf
Set services to start on boot
update-rc.d gpsd enable wget -o /etc/init.d/direwolf https://raw.githubusercontent.com/elafargue/aprs-box/master/config/etc/init.d/direwolf chmod +x /etc/init.d/direwolf ln -s /etc/init.d/direwolf /etc/rc2.d/S06direwolf chmod +x /etc/rc2.d/S06direwolf
Modify /etc/ntp.conf to use GPS by adding these lines
server 127.127.28.0 minpoll 4 maxpoll 4 iburst fudge 127.127.28.0 time1 +0.130 refid GPS
I picked up a el-cheapo clear plastic enclosure for $1 to mount all the cables and boards in and keep things from shifting around. My plan is to eventually 3D print an enclosure once I have everything finalized.
Works well for around town, but not enough power to hit distant repeaters except intermittently.
I took it up showshoeing again this time at Hell’s crossing/Pleasant Valley and didn’t get a single ping up the pass. I did get a few pings on BETHAL on the way up, which I am happy about since I should have before.
Since I am seeing long haul truckers with 25-50W APRS transmitters hitting repeaters hundreds of miles away with consistency, I can only surmise my little 5W chinese HT just isn’t getting out. What I really wanted to find was a dual band (2m/70cm) dual VFO radio to dash mount and dedicate the second VFO to APRS. However, I wasn’t able to find a good radio that fit the bill. Backup plan is to get a cheap dedicated radio for APRS.