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GeoStamp® Wireless: Wireless GPS On-screen Video Overlay with Audio Track Encoding and PC Layout Utility
Discontinued Product - No Longer Available for Ordering




GeoStamp® Wireless overlays wired RS-232 or wireless Bluetooth GPS receiver data (latitude, longitude, heading, speed, date, time) and optional user defined messages onto an incoming composite video source such as a video camera output. In addition to overlaying GPS data onto the video image, GeoStamp® Wireless also simultaneously encodes the GPS NMEA data into a continuous audio stream that can be recorded onto an audio track, such as one of the stereo audio input channels of a video camcorder or DVR. The remaining audio channel is often used for voice annotation. The encoded audio track, when played back into GeoStamp® Wireless and decoded, provides a synchronized RS-232 or Bluetooth GPS data stream that can be sent to a PC for location tracking via PC mapping software.


The GeoStamp® Wireless miniaturized module is configured via supplied PC utility allowing the user to select and position the on-screen data fields, customize the data formats, and enable optional displayed auxiliary peripheral triggered inputs such as the status of squad car lights and sirens. The Windows based utility, called gswLayout, uploads all user configuration settings via a PC RS-232 serial port to the GeoStamp® Wireless' non-volatile memory. Users can customize the on-screen display to meet their exact operational needs.


GeoStamp® Wireless contains an internal miniature Li-ion battery pack that will power the device for up to 12 hours before needing recharging.


GeoStamp® Wireless Specifications:

  • Dimensions: 3" x 2 3/4" x 1"
  • Weight: 5 oz
  • Input voltage: 8.0 to 14.0 volts DC (220 ma max.)
  • 12 hours continuous on fully charged battery
  • DC plug 2.1 mm x 5.5 mm, center tip positive
  • Operating temperature: -10 C to +70 C
  • Video level: 1 volt peak to peak
  • Video impedance: Input 75 ohm, output 75 ohm resistively terminated
  • GPS input: NMEA 0183 GPRMC sentence, 9600 baud, 8 data bits, no parity, one stop bit
  • Decode PC Bluetooth passkey: 1234
  • Audio modulation: FSK
  • Audio input level range: -40.0 to -8.0 dBV
  • Audio output level: -10dB +/- 1dB
  • Acceptable audio signal to noise ratio: 20.0 dB
  • User message length: 10 characters
  • 3 external trigger inputs (pull to ground)
  • External trigger message length: 5 characters (each)
  • Selectable GPS fields: latitude, longitude, heading, speed, date, and time
  • Speed format: MPH, KPH, and knots
  • Heading format: compass (e.g. NW) or degrees
  • Time format: UTC with time zone adjustment



GeoStamp® Wireless has five connections (see below)


Attach To

12 VDC
  • DC IN +8 to +14 volts DC
  • 2.1 mm x 5.5 mm DC coax plug, center tip positive
Ext GPS PC Wired GPS Hookup
If a Bluetooth wireless GPS receiver is not used then attach to a compatible NMEA 0813 GPS receiver with the supplied programming cable and Null Modem adapter.
2.5mm 4-conductor plug
  • Tip: TX GPS
  • Ring 1: RX GPS
  • Ring 2: GND
  • Ring 3: Unused
gswLayout PC Uploads
Attach supplied programming cable to the PC RS-232 serial port
2.5mm 4-conductor plug
  • Tip: TX PC
  • Ring 1: RX PC
  • Ring 2: GND
  • Ring 3: Unused
AUX Attach up to 3 external trigger input devices
Pull to ground to display text
2.5mm 4-conductor plug
  • Tip: Switch IN 2
  • Ring 1: Switch IN 3
  • Ring 2: GND
  • Ring 3: Switch IN 1

(Used for encode mode)
Camera video/audio output
3.5mm 4 conductor plug to 3 RCA plugs
  • Yellow RCA - Video IN
  • Red RCA - Right audio channel ignored
  • White RCA - Left audio channel pass-through
(Used for encode and decode mode)
Camcorder or DVR video/audio input (encode mode)
Camcorder or DVR video/audio output (decode mode)
3.5mm 4 conductor plug to 3 RCA plugs
  • Yellow RCA - Video OUT
  • Red RCA - Right audio channel GPS encoded audio
  • White RCA - Left audio channel pass-through

GeoStamp® Plus Wireless Rear View


GeoStamp® Wireless configuration is performed through a combination of on-screen menu system and a Windows based PC utility program called "gswLayout".  "gswLayout"  (see below) allows the enabling, positioning, and format selection of the on-screen GPS fields. This information is uploaded to GeoStamp® Wireless via a PC RS-232 serial port and is stored internally in the GeoStamp® Wireless device's non-volatile memory.


To install gswLayout insert the CD and run setup.exe. Follow the installation instructions. After the installation is complete the gswLayout program will be located in the Start>>Programs>>gswLayout folder.


The gswLayout utility draws a simulated screen output on the PC. Each GPS field can be enabled, positioned, and if applicable, the format and label type can be selected. The UTC offset represents the UTC time zone adjustment (e.g. -5 Eastern Time). This allows for local date and time to be displayed. The "Load From Disk..." and "Save To Disk..." buttons allow loading and saving screen configurations to the PC. The "Upload To GeoStamp® Wireless®" button initiates an attempt to send the current GPS field layout configuration data via the selected PC Com Port to GeoStamp® Wireless.


GeoStamp® Wireless must be ready to receive the gswLayout data by making a selection on the on-screen menu (see on-screen menu section below.)


GeoStamp® Plus Wireless Layout Utility

(Click to enlarge)


Note: The gswLayout PC utility requires a Windows 2000, XP, or Vista PC with a minimum 800 x 600 display and one RS-232 serial port.


GeoStamp® Wireless On-Screen Menu Configuration

At any time press the UP and DOWN buttons simultaneously on the GeoStamp® Wireless front panel to enter the on-screen menu configuration. Once in the main menu the UP or DOWN buttons move the cursor up or down and the ENTER button makes selections.

Menu Option

Selection / Action

Operating Mode
  • ENCODE - Encode incoming GPS on-screen and in the audio track.
  • DECODE - Decode previously recorded audio generating GPS NMEA data.
On-screen Display
  • OVERLAY - Overlay the GPS text onto the incoming video source.
  • SELF-GEN - Overlay the GPS text onto a self generated blue background screen. No camera video input is required.
  • OFF - Pass the camera video through without overlaying the GPS text.
GPS Source
  • BT - Bluetooth GPS receiver.
  • DB9 - RS-232 GPS receiver connects to the Ext GPS connector.
Decoder Output
  • BT - Bluetooth PC or PDA (remote device will initiate connection.)
  • DB9 - RS-232 PC connects to Ext GPS connector.
  • OTHER - GeoStamp® Wireless initiated connection to other Bluetooth device.
UTC Offset
  • UTC offset for local time
Pair to BT GPS: Execute Pair GeoStamp® Wireless to the Bluetooth GPS receiver. This action is only required once when a new GPS receiver is used. Turn power on the GPS receiver then select this option. The GPS receiver does not have to have a view of the sky
Pair to Other: Execute Pair GeoStamp® Wireless to a Bluetooth device that will receive the NMEA decoded output. GeoStamp® Wireless initiates the connection when in decode mode. (Not normally used.)
Download from PC: Execute Receive configuration data from the PC "gswLayout" utility.
Exit Exit the main menu


GeoStamp® Wireless operates either in encode or decode mode depending on the on-screen menu setting. Press the UP and DOWN buttons simultaneously to enter the on-screen menu once a video monitor is connected to the OUT A/V connector.


Encode Mode

Upon power being applied, GeoStamp® Wireless attempts to communicate with the GPS receiver. The GPS receiver status field, if enabled in the gswLayout utility, indicates GPS receiver connection status. A CLOCK icon or "Searching for Bluetooth GPS" message indicates communication to the GPS receiver has not been established. Once communications to the GPS receiver has been established a SATELLITE DISH icon is displayed while GeoStamp® Wireless waits for four satellites to lock. Once lock has occurred then the real-time GPS information is displayed on-screen and audio encoding begins. GeoStamp® Wireless updates the screen and sends an audio packet burst after each valid NMEA GPRMC sentence has been received from the GPS receiver.


Note: If using a Bluetooth GPS receiver you must select "Pair to BT GPS" once before the GPS encoding operation will work.


Typical settings to encode using a Bluetooth GPS unit:

--------- MAIN MENU ----------
Operating Mode: ENCODE
On-screen Display: OVERLAY
GPS Source BT
Decoder Output: BT
UTS Offset: 0
Pair to BT GPS: Execute
Pair to Other: Execute
Download from PC: Execute


Decode Mode

Upon power being applied, GeoStamp® Wireless attempts to communicate with the PC. If Bluetooth is the selected decode output method then GeoStamp® Wireless waits for a connection to be initiated by the PC. When pairing the PC to GeoStamp® Wireless (only required once) you must be in this decode mode and specify a passkey of 1234 on the PC.


Now simply rewind the video and press the play button on the camcorder. The previously encoded audio will be fed back into GeoStamp® Wireless and decoded via the OUT A/V connector.


Typical settings to decode using a Camcorder for playback (connect camcorder to "OUT A/V" video connector) and sending the data to a Bluetooth PC:

--------- MAIN MENU ----------
Operating Mode: DECODE
On-screen Display: OVERLAY
GPS Source BT
Decoder Output: BT
UTS Offset: 0
Pair to BT GPS: Execute
Pair to Other: Execute
Download from PC: Execute


Note: The main menu operating mode setting (encode or decode) can be overridden by holding the "down" button (force decode mode) or "up" button (force encode mode) during power up. This is a "one time event" and must be exercised each time if the default mode is set to ENCODE and the user wishes to change the mode temporarily to DECODE for one use or vise versa.

LED Status

Abbreviation LED Status
P Green Power
C Red Battery Charging
B Blue Bluetooth device connected
G Yellow GPS Satellite lock


GeoStamp® Plus Wireless Front View



Warranty & Service:

If the product fails to perform as described in our product description or specification, within 90 days from the date of shipment to the buyer, we will repair or replace the product and/or accessories originally supplied. Failure due to improper installation, misuse, abuse or accident is not covered by this warranty. Incidental and consequential damages are not covered by this warranty.The buyer must obtain a Return Material Authorization by calling (248) 588-4400, and shipping the defective product to Intuitive Circuits, 3928 Wardlow Ct., Troy, MI 48083, freight prepaid. After the warranty expires, we will promptly supply an estimate for the repair cost.


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