I'm trying to get an Adafruit Ulitmate GPS Hat to work on my new RPi3
/boot/cmdline.txt
has been modified to remove references to ttyAMA0:
pi@gpsp3:/boot $ more /boot/cmdline.txt
dwc_otg.lpm_enable=0 console=tty1 console=serial0,115200 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=
yes rootwait
I'm running Jessie so I executed:
sudo systemctl stop serial-getty@ttyAMA0.service
sudo systemctl disable serial-getty@ttyAMA0.service
and rebooted.
When I try:
cat /dev/ttyAMA0
the console just hangs.
The GPS LED is blinking once every 10 seconds which suggests it's gotten a lock, and as I understand it, it should be outputting an ASCII data stream even if it didn't have a lock. It has to be one of the following issues:
- The UART isn't set up correctly.
- The GPS has a faulty device.
Other than dragging the unit into my workplace and putting an oscilloscope on the UART pins, does anyone have any suggestions?