Active GPS Text and Graphic Overlay


Description

The objective of this application example it to overlay GPS data (in NMEA 0183 format), date and time text on a blue background complete with a user graphic/logo located in the bottom right corner of the display. 

Active Text and Graphic Overlay

Microtronix Application Solution 


This application example is implemented using the Microtronix SD/HD-SDI Text and Graphics Overlay Inserter product (PN: DX-2200-TI-24). 


The DX-2200 is configured with a video feed on the primary SDI input. The GPS and time/date information is supplied from a local computer connected to the RS-232 Serial Control port or via a serial Data Port connection per Note 1 below. The data is continuously streamed to the unit using the DX-2200 command-line syntax of the serial control protocol. The blue background color line was sized and positioned to ensure the text was clearly visible to the user. 


The graphic logo is uploaded to the unit and stored in on-board flash. Serial commands are used to control the position of the graphic element. The overlay information can be turned ON and OFF as required.  Up to three overlay layers can be used as required to ensure optimal ease of and maximize performance in configuration in which come text elements are fixed and others are dynamic. 


NOTES: 

1) The GPS information can alternately be supplied by connecting a NMEA 0183 compatible GPS device directly to the serial port of the DX-2200-TI using a Microtronix Serial Y-cable adapter to supply an extra Serial Data Port connection. 

2) Some details of the text overlay may differ based on what text fields and data formats the GPS messages supplied.

3) A similar application drawing is supplied in the “DX-2200-TI-03 - Text Inserter – User Manual -v1-91” including Figure 23 showing details of electrical serial connection to a GPS device using a Y-splitter cable. A sample of an overlay on black background is documented in Figure 24 of the User Manual along with the associated serial commands that generate it.


Both the DX-2200-TI-24 and the DX-4400-TI-2K video overlay products support this type of functionality.