I am also doing similar project with raspberry pi 4 (bullseye version) and neo 6m module. I have followed all the steps given in https://sparklers-the-makers.github.io/blog/robotics/use-neo-6m-module-with-raspberry-pi/ but I do not see any output when I do sudo cat /dev/serial0. It simply hangs, does not crash pi. Ctrl+C brings the unix prompt back, The blue light on the antenna is blinking as suggested by the article.
I don't know which other settings I am missing. Here is the gist of the tutorial:
- I am trying to read the GPS data by using Raspberry Pi 4 + Neo 6M GPS module
- I edited /boot/config.txt and added dtparam=spi=on dtoverlay=pi3-disable-bt core_freq=250 enable_uart=1 force_turbo=1 at the bottom of the file
- I created a backup of /boot/cmdline.txt and in the new cmdline.txt file, added dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait quiet splash plymouth.ignore-serial-consoles
- After rebooting, sudo cat /dev/ttyAMA0 hangs. I checked that /dev/serial0 is linked to ttyAMA0. I also used raspi-config to disable login and lastly, I also performed sudo systemctl stop serial-getty@ttyAMA0.service sudo systemctl disable serial-getty@ttyAMA0.service but sudo cat /dev/ttyAMA0 or /dev/serial0 still hangs. Note that the blue light on the antenna is blinking which means the antenna is receiving data. Is it transmitting the data to pi? I don't know. Is there anyway to find it out other than sudo cat /dev/ttyAMA0?