WPS



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Waypoint Sequencer

The waypoint sequencer (WPS) is designed to provide waypoint navigation in radio-controlled aircraft systems using a simple GPS module that does not have its own waypoint capabilities. The WPS can be programmed with a list of waypoints to be followed. It then accepts data from the GPS module and calculates range and bearing information which it outputs as $GPRMB sentences to be used by a navigation computer.

WARNING: This is experimental technology. Implementation requires technical skills involving soldering, electronics, avionics, aeronautics, hydroponics, etc. The user should ground test and verify proper operation. A range check should be passed before using in flight. This could cause your aircraft to crash. The user assumes all responsibility for its use. There is no warranty. Your mileage may vary.

Key Features

Stores up to 60 waypoints.
Passes through all received GPS sentences.
Calculates and outputs $GPRMB sentences.
Configurable parameters:
- arrival range
- arrival or departure sequencing
- sequence once, sequence repeat, or sequence and return to origin
TTL serial input/output.
Configurable baud rate: 2400, 4800, 9600, 19200, 38400, and 115200 baud.
Input and output standard NMEA 0183 sentences.
Onboard voltage regulator - accepts wide range of input power: 4 - 15 volts.
Firmware upgradeable.
Only 3.5 grams.
1.57" x 0.92" x 0.37" (40 mm x 23.4 mm x 9.4 mm).
Note to European users: this is not yet RoHS compliant.

Sample Input:

$GPGGA,023534.000,3913.7744,N,12105.3693,W,1,08,1.0,784.6,M,-21.8,M,38.8,0000*72
$GPGSA,A,3,03,13,27,23,16,08,28,19,,,,,1.7,1.0,1.3*3F
$GPRMC,023534.000,A,3913.7744,N,12105.3693,W,2.49,141.91,240506,,*14
$GPGGA,023535.000,3913.7739,N,12105.3686,W,1,08,1.0,784.9,M,-21.8,M,38.8,0000*72
$GPGSA,A,3,03,13,27,23,16,08,28,19,,,,,1.7,1.0,1.3*3F
$GPGSV,3,1,11,13,78,078,42,27,54,292,35,23,44,120,43,08,28,269,30*7D
$GPGSV,3,2,11,03,26,084,41,19,18,119,36,16,13,042,31,10,09,324,28*7D
$GPGSV,3,3,11,28,09,211,33,20,07,173,28,07,05,038,32*4A
$GPRMC,023535.000,A,3913.7739,N,12105.3686,W,2.46,130.34,240506,,*1D
$GPGGA,023536.000,3913.7734,N,12105.3679,W,1,08,1.0,785.0,M,-21.8,M,38.8,0000*74
$GPGSA,A,3,03,13,27,23,16,08,28,19,,,,,1.7,1.0,1.3*3F
$GPRMC,023536.000,A,3913.7734,N,12105.3679,W,2.76,139.36,240506,,*1B

Sample Output:

$GPGGA,023534.000,3913.7744,N,12105.3693,W,1,08,1.0,784.6,M,-21.8,M,38.8,0000*72
$GPGSA,A,3,03,13,27,23,16,08,28,19,,,,,1.7,1.0,1.3*3F
$GPRMC,023534.000,A,3913.7744,N,12105.3693,W,2.49,141.91,240506,,*14
$GPRMB,A,0,L,002,003,3913.7670,N,12105.3585,W,0.020,132.03,000.0,V*38
$GPGGA,023535.000,3913.7739,N,12105.3686,W,1,08,1.0,784.9,M,-21.8,M,38.8,0000*72
$GPGSA,A,3,03,13,27,23,16,08,28,19,,,,,1.7,1.0,1.3*3F
$GPGSV,3,1,11,13,78,078,42,27,54,292,35,23,44,120,43,08,28,269,30*7D
$GPGSV,3,2,11,03,26,084,41,19,18,119,36,16,13,042,31,10,09,324,28*7D
$GPGSV,3,3,11,28,09,211,33,20,07,173,28,07,05,038,32*4A
$GPRMC,023535.000,A,3913.7739,N,12105.3686,W,2.46,130.34,240506,,*1D
$GPRMB,A,0,L,002,003,3913.7670,N,12105.3585,W,0.020,129.99,000.0,V*31
$GPGGA,023536.000,3913.7734,N,12105.3679,W,1,08,1.0,785.0,M,-21.8,M,38.8,0000*74
$GPGSA,A,3,03,13,27,23,16,08,28,19,,,,,1.7,1.0,1.3*3F
$GPRMC,023536.000,A,3913.7734,N,12105.3679,W,2.76,139.36,240506,,*1B
$GPRMB,A,0,L,002,003,3913.7670,N,12105.3585,W,0.019,131.71,000.0,V*34

Discussion thread:

http://www.rcgroups.com/forums/showthread.php?t=515929

Board diagram and pinouts:

Sample hookup diagram with RCAP2 navigation controller and US GlobalSat EM-406 GPS module:

PC Application for configuring and importing waypoints:

Download Version 1.4

Firmware Updates:

To download, right-click and select "Save Target As". You must save the .hex file. Double check by looking at
the file in a text editor. Every line should start with a colon (:), something like this:

:04FFF00023001E00CC
:08FFF800000000000000000001
:03000000022F7A52
:0C2F7A0078FFE4F6D8FD75817E022FC1BF
:1036430057502053657175656E63657200302E3770
:0D365300004A756E203137203230303600CD

Do not attempt to program if that is not the case.
Programming with a bad file will kill the processor.

Version 0.9	Adds a logic output on pad J3_1. Output is normally high, but goes low when each waypoint is achieved.	2006-08-20
Version 0.8	Couple changes to GPRMB sentence for Garmin format. Blink center LED on each GPS sentence to indicate activity. Fix hanging bug (I think).	2006-06-28
Version 0.7	Fix for departure sequencing.	2006-06-17
Version 0.6	Original release	2006-06-07

Updating the firmware:

To update the WPS firmware, you need the free Philips FlashMagic ISP loader from Here

Update Procedure:

1) Connect PC serial port (both transmit and receive) to WPS using level converter.

1) Power up the WPS while pressing and holding the pushbutton.

2) Run FlashMagic.

3) Set FlashMagic options as shown below:

4) Click "Browse" to select the Hex File you downloaded.

5) Click the ISP menu.

6) Click "Start Bootloader" menu item.

7) Select "Send Break Condition".

8) Click "Start Bootloader" button.

9) Click "Start".

Serial Commands:

CommandSet.txt

Schematic:

Version 02