The Las Vegas Boulevard Tracker Interface

Taking into account the issues surrounding existing trackers, for a couple of years Howard, G6LVB has contemplated the possibility of providing backwards software and hardware compatibility, but simultaneously supporting newer interfaces such as USB and at a reasonable price. Simplicity of construction was also at the forefront of any design decision, with the aim of being no more complicated than a FODTrack to construct.

 For more advanced construction, there are also several options available such as an LCD display and configuration buttons, or the option to choose between USB or RS-232 and maintain backwards compatibility with existing software. Because the unit uses a microcontroller, of prime concern was also the provision for the user to be able to program the unit without the need of a programmer.

With this in mind, the LVB Tracker was born. The heart of the tracker is the PIC16F876 microcontroller, including A/D converters, a bidirectional asynchronous serial port, in-circuit programming,

The FODTrack interface is so simple that a microcontroller is not used. This simplicity means that there is no requirement to program the FODTrack unit. Often, constructors are put off implementing microcontroller applications because of the requirement for a costly programmer. The LVB Tracker incorporates the programmer as an integral part of the unit. By changing three jumpers on the LVB Tracker, it is possible to use the trackerís computer interface for programming purposes, so a programmer is not required.

 When later software updates become available, the LVB Tracker can simply be switched into programmer mode and the updates programmed directly.

 More and more predominant are USB interfaces. The LVB Tracker may use either a standard RS-232 connection or a USB interface. If the USB interface is chosen, when connected to the computer and the appropriate USB drivers are installed, the LVB Tracker appears as a standard RS-232 serial port despite it being a USB connection. This allows existing software packages such as Wisp and Nova to be used. USB drivers are available for Windows 98, ME, 2000 and XP, Mac OS-8, OS-9 and OS-X as well as being built into Linux, Open BSD and Free BSD.

For the software protocol, LVB Track supports subsets of the two most common interface protocols: the Yaesu GS-232 and Easycomm I/II. The firmware automatically switches protocols and automatically responds in the appropriate format.

Calibration settings are stored in EEPROM within the microcontroller. Typical settings include the A/D values at the end stops.

The optional LCD and optional pushbuttons allow the operator to see the rotator status and configure the unit without using a terminal emulator.

This is the schematic of the LVBT