improved troubleshooting tips

examples/AutoGridCL/README.md

@@ -41,6 +41,7 @@ Using a text editor (e.g. Notepad or Visual Studio Code), modify 'AutoGridCL.py'
 
 ![configure AutoGridCL](img/configure-autogridcl-img0821.jpg)
 
+
 ## Run AutoGridCL
 
 WSJT-X must be started first. AutoGridCL will not retry if it fails to find WSJT-X - it throws an exception and ends.
@@ -67,13 +68,17 @@ When you end AutoGridCL, its last grid will linger until you change it, or resta
 
 ## Troubleshooting
 
-Error reporting is very crude in this prototype program. You will need to be resourceful to troubleshoot problems at this early stage.
+Error reporting is fairly basic in this program. You will need to be resourceful to troubleshoot problems at this early stage.
+
+In theory, this program should work with several different USB-attached GPS pucks. As long as the GPS sends standard NMEA data with lat/long position in $GPGGA or $GPGLL sentences, this will automatically decode them. We tested and recommend GPS pucks based on the GlobalSat BU-353-S4 chipset, typically $50 on Amazon in 2022.
 
-In theory, this program should work with several different USB-attached GPS pucks. As long as the GPS sends standard NMEA data with lat/long position in $GPGGA or $GPGLL sentences, this will automatically decode them.
+The serial port for Griduino can only be opened by one program at a time, causing it to be mutually exclusive with programs like NMEA Time2. If you want full-time GPS-based clock synchronization, some work-arounds are:
 
-Using AutoGridCL is mutually exclusive with NMEA Time2. The serial port for Griduino can only be opened by one program at a time. 
+* AutoGridCL and NMEA Time2 can run together if they each have their own GPS receiver and serial port. 
+* Run [JTSync](http://www.dxshell.com/jtsync.html) instead of [NMEA Time2](https://www.visualgps.net/).
 
 Here are some suggestions that might help.
+
 * If a command-line window does not appear after starting AutoGridCL.py, then it might have an exception and have ended right away. To see messages, open a command window, change to the directory where the file is located, and type 'python AutoGridCL.py'
 * If you don't see NMEA messages from Griduino, reboot it and watch the screen to see the version number. Griduino software version must be 1.10 or later.
 * If this program can't connect to Griduino, close any programs using it (such as NMEA Time2 or the Arduino workbench) before starting AutoGridCL. Note that the USB port cannot be shared, so only one program at a time can listen to Griduino. For extra fun, note that NMEA Time2 is a background service and cannot be closed; you must configure its GPS setting to 'Off' to disconnect it from the serial port.