Re: [gpsd-users] TOFF and PPS values from gpspipe

[Kaya Saman]

Yo Gary! Thanks for all the help!! :-) :-)


On 8/29/19 12:51 AM, Gary E. Miller wrote:
> Yo Kaya!
>
> On Wed, 28 Aug 2019 21:35:46 +0100
> Kaya Saman <address@hidden> wrote:
>
> > > > I'm writing a script in order to be able to display certain
> > > > information from GPSd on a 20x2 line character LCD display.
> > > Did you look at lcdgps.c in the gpsd source?  That is exactly what
> > > it already does.
> >
> > Yep I did. The only issue is that it requires LCDproc of which there
> > isn't a driver for my Newhaven display :-( <- my idea was to write a
> > driver for it but have no experience there so it's basically another
> > story lol
> At least that gives you a starting point.  When you get someething
> running we would appreciate a copy we can share with the next person.
>
> [ Snip]


I created a folder to show what I've done. It's a pretty custom job 
based around 2x Pine64-LTS SBC's. The 3rd Pine is just for messing 
around with and trying out stuff.


Most of the parts were sourced from Mouser Electronics in TX, though the 
DIN enclosures for the NS35 rail and TXS chips came from Italy in Europe.


Basically both Pine's run FreeBSD 13-Current. The one with a green color 
display is linked to a Garmin 18x-LVS through a 6 pin Conxall connector. 
This then is fed in to an Artekit TTL to RS232 shifter board with the 
PPS signal being fed into a 5mm 5V red LED and also channel 2 of the 
RS232 shifter; which then feeds the UART CTS pin on the Pine's expansion 
header:


http://synfare.com/599N105E/hwdocs/pine64/gpiosgeo.html


I'm using uart2 for the displays and uart4 for the GPS. Quick note: the 
PPS signal I inverted in the OS after tests with the shifter showed that 
the output was inverting the original -> dev.uart.4.pps_mode=17


I tried various shifters for the Newhaven displays however, after some 
trial&error and understanding better how the LCD controller works and 
that it includes 'pull-up' resistors on board the Aretekit TXS chip was 
the correct choice.


As mentioned the Newhaven's don't have an Lcdproc driver which I will 
need to look at in the future. They are based on the HD44780 codeset but 
it is converted on the PCB from separate commands centric to the 
Newhaven serial range of displays. <- this is because they have I2C and 
SPI interfaces as well.


Here is the link: 
https://ncloud.optiplex-networks.com/index.php/s/y5ggsWKDpgzCfDN


I have also uploaded my scripts too... they do work somewhat but are not 
100% complete. I'm still tuning them to provide desired output based on 
the GPIO input from a tactile switch on the front panel.


The system with the blue display is an Astronomic clock and sources it's 
time from the Stratum2 NTP servers in the network which clock the 
Stratum1 Pine provided by the Garmin 18x. This then pushes 
sunset/sunrise times to the GCE Electronics IPX800v4 controller which I 
am using in my BMS (building management system).


Overall it's a large project which I've had to build from the ground up 
including re-designing and wiring the whole buildings electrical layout. 
But it was well worth it eventually as the system seems to have become 
more intelligent then me at the moment lol :-) :-)


Best Regards,


Kaya