"Example Commands for changing the LCD Display Options on the BG7TBL LCD-GPSDO"For the normal default display of 'UTC Time and Frequency Hz: $GPGTC,0 UTC +0000T*
Note: You would use this if you wanted to restore the default, from currently having a different Display enabled.
Note: These Display Command strings each require a single space before 'UTC', and a double (2 spaces)
after 'UTC'. To Display 'UTC Time' and 'Freq. Error in PPB': $GPGTC,2 UTC +0000T*
To Display 'EST Time' and Freq. 'Error in PPB': $GPGTC,2 EST +0500T*
To Display 'EST Time' and Frequency in Hz: $GPGTC,0 EST +0500T*
Suggestion: Before using EST, or any other Time Zone that also uses Daylight Savings Time (DST) think about the consequences of possibly having to deal with DST. I initially wanted to use EST, and then decided to stay with UTC. And by the way you can also label it GMT if you want, just replace UTC with GMT in the command string.
My unit is working great and I especially enjoy having the capability for displaying Frequency Error in PPB.
FYI: 001.00, or 1 ppb is 1 part in 10 to -9 (0.01 Hz @ 10 MHz), and 000.01 is 1 part in 10 to -11 (0.000,1 Hz @ 10 MHz) may also be referred to as 10 parts in 10 to -12.
Here is a Programming Tip I discovered that I suggest you use: If you want to send a command to the GPSDO in one shot then send it twice in one string. So for example if you want to send
$GPGTC,2 UTC +0000T* (remember to use the 1 and 2 spaces), send it as
$GPGTC,2 UTC +0000T*$GPGTC,2 UTC +0000T* I informed BG7TBL about this, it works, and is Ok to use. This is not complicated, and if you want to program the LCD for a Optional Display format, you only have to do it once!
To program a GPSDO LCD Display Option: With the GPSDO's top cover removed, place a connection across the Test/Program Jumper located on the main PCB, just behind the Rear Panel's 3 LEDs. Send your command through the Rear Panel's RS232 connector. Remove the Test Jumper connection. Remove DC Power for a few seconds, reapply DC Power. Your GPSDO should boot up and display your new LCD format.
I use a 'USB to Serial Port (RS232) Cable/Adapter' between my PC and the GPSDO for Programing and Monitoring. Very inexpensive on eBay.
For Monitoring I prefer: VisualGPSView, freeware,
http://www.visualgps.net/, very easy to setup, use, and to see the Satellite Signal Levels from a distance, and no magnifying glass is required.
For Programming I prefer: 'Termite' Terminal Emulator, freeware,
https://www.compuphase.com/software_termite.htm, very easy to use and setup, and it is a Portable Application that you just Run, as no installation is required (you can even run it from a USB Thumb Drive), and it works perfectly with this GPSDO.
Configuration Settings for Termite: Port: A/R (press 'v' to see what is available), Baud rate-9600, Data bits-8, Stop bits-1, Parity-none, Flow control-none, Transmitted text-Append nothing, Receive text: Polling-500 ms, Max lines-25, Options: Stay on top, Quit on Escape, Automatic edit line, Keep history, Plugins-noneEnjoy the Optional LCD Display Options: The default display itself is great, so there is no reason to change, but we have the options thanks to BG7TBL.
Miscellaneous:1. The potentiometer, RP1, on the Display Board is a Contrast adjustment for the LCD.
2. I configured my unit to supply 5 VDC to the GPS Antenna (vs. the default 3.3 VDC) because my Active GPS Antenna and In-line GPS Pre-Amp are both designed for 5 VDC operation. To do this move the SMT Fuse from 'ANT 3.3V', to 'ANT 5V' (these are clearly marked) on the bottom of the Main PCB next to the U-blox GPS Receiver IC.