[time-nuts] GPS seconds conversion on an Arduino

Ben Hall kd5byb at gmail.com
Sun May 14 17:16:11 EDT 2017

Hi Chris and list,

My original goal was to duplicate, more or less, what the PackRat guys 
did to get the TruePosition boards up and functional as described here:


I did get in touch with them and they forwarded the HEX files.  I 
haven't tried them yet, but another list member did try them without 

I figured, as a learning exercise, I'd program up my own interface.  The 
boards do not talk NMEA...but output their own format of message.  One 
message contains GPS time in seconds...plus the number of leap seconds 
that have elapsed, so my goal there was to convert the GPS time from the 
unit into normal UTC date and time.

On 5/14/2017 12:38 PM, Chris Albertson wrote:
> Unless this is an educational exercise I'd move to a different processor.
> One of those $3 Arm M3 units has enough  memory AND a more standard
> development environment that you could use a standard library function to
> do what you need.

It is an educational exercise...but I'm still going to look into this. 
Another list member suggested a different Arduino board that had two 
real serial ports, as right now the Uno board I'm using only has one 
hardware serial port with a second duplicated in software.  (one port 
talks to the TruePosition board...the other is debugging output port)

I did happen to recall that I included a Teensy-LC board (Cortex M0) in 
a recent OSHPark PCB order...and it appears to have three hardware 
serial ports...so this may be the way I go eventually.

One of the reasons I liked the Uno was due to all the tutorials and 
example code floating around...plus the nice selection of libraries...as 
I'm not a programmer.  My code would probably make a real programmer 
lose his or her lunch.  :(

thanks much,

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