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+--- Thread: RPi 4 Serial UART for GPS input (/showthread.php?tid=3717)
RPi 4 Serial UART for GPS input - crocks32 - 2021-10-02
Hi There,
I have a pi4 that I am trying to get a ublox 7m GPS module working on via the UART GPIO15 pins.
I am stumped regarding the primary and secondary UART serial connections. Apparently on the pi4 they are different (with a miniuart) to the earlier ones
There are a few overlay options one can specify in the config.txt file I have tried a few already, resulting in ttyAMA0, ttyAMA1, ttyS0, but I still cannot get any of this data into signal k after aliasing the device and setting a connection in the serial dialog.
in my config.txt I have the following
dtoverlay=disable-bt
dtparam=spi=on
enable_uart=1
core_freq=250
dtoverlay=uart5,ctsrts
these values come from the https://www.raspberrypi.org/documentation/computers/configuration.html#configuring-uarts
documentation. But I still cant work it out. Has anyone else had to deal with this?
The easy option is aparently to go and get a USB GPS dongle. But I had this ublox NEO 7m by duinotech. It has an onboard antenna but also an sma to run an external antenna. I have previously read the nmea gps messages in sudo cat /dev/(serial port). but not through to signal k.
The module and guts of connecting this device I found in this video https://youtu.be/N8fH0nc9v9Q but i did not run the python scripts as I wish to use it with OP.
An help would be appreciated.
Thanks
C32
RE: RPi 4 Serial UART for GPS input - crocks32 - 2021-10-04
OK Update, as follows
I edited my config.txt file to include
dtoverlay=uart5,txd1_pin=08,rxd1_pin=10
re-ran
sudo cat /dev/ttyAMA0
Got illegible GPS data.
Edited the serial device connection to signal K and set the baud to 9600.
Still no throughput to signal K.
hard Set the serial Baud rate to 9600 in terminal using
stty -F /dev/serial0 raw 9600 cs8 clocal -cstopb
reboot
and...boom!
Problem solved. working like a charm. (5 total signal k throughput deltas/second and 15 signal k paths)
[url=https://www.raspberrypi.org/documentation/computers/configuration.html#primary-uart][/url]