Can you provide additional documentation on the SparkFun GNSS L1/L5 Breakout. For example can the buad rate be changed? How do you force NMEA0183 output only? I am attempting to use with a Raspberry Pi5 to set the time when there is no network connection. Location is secondary but useful. I am NOT using USB. I am connecting via pins VCC, GND, TX, RX & PPS. I spoke with Joelle who asked me to post here.
Hi @mesgps ,
Which L1/L5 breakout do you have? NEO-F10N or NEO-F9P?
If you have the NEO-F10N, then please see this section. This Interface Description is the best source for more information.
By default, the NMEA 0183 GGA, GLL, GSA, GSV, RMC, and VTG messages are enabled at 38400 baud.
There are two ways to change the baud rate:
You can send a UBX binary message which sets the UBX-CFG-VALSET CFG-UART1-BAUDRATE.
Or you can send a NMEA-format PUBX CONFIG message. Please see section 2.8.1 in the interface description. PUBX is easier since it is ASCII and human-readable. The only tricky bit is calculating the NMEA checksum bytes. But there are plenty of code examples and online tools out there to help.
I hope this helps,
Paul
Thank you Paul, Yes, it is the F10N. This helps a lot. I have not delved into this much detail since I wrote assembly code by hand in the 1980s. I’ll have to shake the cobwebs out of my brain. As it turns out, most of the problem seems to be on the Pi side getting serial0 initialized at boot to 38400. Somewhere it is getting set to 9600, ignoring my initialization. Once I manually stty to 38400 all works as intended. With this documentation I may go a lot deeper than just using it as a time source. The project is for HAM radio portable operation. Thanks again.
Hi @mesgps ,
No problem! Glad we could help. (I was writing 8051 assembly code by hand in the '80s too!)
All the best,
Paul