Blog 18– Hamlib Now Supported

While working to bring a Dual Axis Rotor system online with the SatNOGS network of ground stations I found that of the 3 GS232 hardware configuration supported in the Hamlib rotctl library, not 1 work properly with the current GS232A implementation of the 12PRSART System.  After a few hour of experimentation I found the solution and now have a version of the firmware that will work with Hamlib and rotctl.  Check out the SatNOGS project at

Currently the test environment is running on a Raspberry Pi 3B.  I did not want to break anything that is already working in the field so a new version of firmware for the Hand Controller is available to support Hamlib.  Version 1.4E which is field loadable is now on the website.   Firmware version 1.4 has a few minor fixes and timing improvements to better support control applications that do not poll for antenna position, operating blind.  The Hamlib enhancements are found in the ‘E’ version.  Both Hand Controller and Motor Controller must be upgraded to the 1.4x base level.

The command line I found that worked the best for ‘rotctl’ while running on the Pi-3B test system running Raspbian Jesse 2016=2=26 is:

rotctl -m 603 -r /dev/ttyUSB0 -C timeout=500 -C min_az=0 -C max_az=359 -C min_el=0 -C max_el=180

This should be used for all installations using Hamlib.

For use with the SatNOGS network, I also add the following to the command line to limit the rate at which the SatNOGS client running on the Pi 3B sends out move requests:   -C post_write_delay=950

To support the SatNOGS client application, I have released a version that includes a few other needed behaviors to keep the Dual Axis rotor system happy.  The firmware version is 1.4H.

Leave a Reply

Your email address will not be published. Required fields are marked *