R-DAS On Screen Display

R-DAS OSD (On Screen Display) Module


R-DAS OSD Module Front Side R-DAS OSD Module Rear Side

The R-DAS On Screen Display (OSD) Module plugs into the R-DAS via an expansion cable, and enables flight data such as altitude, acceleration, elapsed time, latitude / longitude (if the GPS module is also connected) and custom data to be overlaid onto a video signal.

The OSD module is fully programmable, and is designed, like the Compact R-DAS, to fit in 38mm diameter rockets. In order to use the OSD module, it just needs to be plugged into the R-DAS via the 14-pin expansion cable, and to have a camera plugged into it via the phono input socket, and a transmitter plugged into it via the phone output socket. It is then ready to overlay data!


OSD PROGRAMMING COMMANDS

each display line is fed with a "line" command:

line [v-offset] [h-offset] [text]

the configuration is made permanent with the "store" command.

[v-offset] is the vertical offset of the line, positive values count from the top of the screen, negative values from the bottom.
[h-offset] is the horizontal offset from the left-hand side of the screen.
[text] is the data to display; it can be any text. Data is inserted through sequences escaped by the percent sign.
For example, "%t" will be replaced by the timestamp when displaying data.

Possible characters:
    t: timestamp (s)
    a: barometric altitude (ft)
    A: maximum altitude (ft)
    g: acceleration (G)
    G: maximum acceleration (G)
    l: gps latitude (deg)
    o: gps longitude (deg)
    h: gps altitude (ft)
    s: speed (MpH)
    S: maximum speed (MpH)

Between the "%" and the character, format information can be specified:


OSD PROGRAMMING EXAMPLES

A configuration displaying timestamp, speed, maximum speed on the first line, and altitude, maximum altitude, instantaneous acceleration and maximum acceleration.

conf 2
line 25 9 MARS
line -24 9 %31ts %3s/%3Smph
line -19 9 %4a/%4Aft %21g/%21GG
store

A full configuration including GPS information (latitude, longitude and GPS altitude), as well as timestamp, speed, maximum speed on the first line, and altitude, maximum altitude, instantaneous acceleration and maximum acceleration.

conf 3
line 25 9 MARS
line -24 9 %31ts %3s/%3Smph
line -19 9 %4a/%4Aft %21g/%21GG
line -14 9 %36o %26l %4hft(gps)
store


OSD PROGRAM CONFIGURATION AND UPLOAD

For some reason, there is no documentation issued with the On Screen Display (OSD) board, which is slightly frustrating. Hopefully, the following will go some way towards helping programming of the On Screen Display board:

RDAS Pre configuration

1. Connect the RDAS to serial cable from the PC to the RDAS
2. Open the RDAS Configuration Software
3. Switch on the RDAS
4. Disable the downlink option in the RDAS Configuration Software
5. Switch off the RDAS
6. Disconnect the RDAS to serial cable from the PC to the RDAS


OSD Software Upload

7. Connect the OSD board to a PC with the RDAS to serial cable from the PC to the OSD board
8. Switch on the RDAS (the RDAS provides power to the OSD board)
9. Copy the text from one of the examples above (or from your own example) from "conf x" up to and including "store" (5 or 6 lines in the examples above, including the newline at the end)
10. On the PC, run hyperterminal, set to 57600 baud, 8 databits, 1 stopbit, no parity, no flow control
11. In Hyperterminal, type " v ", you should get a version string in response.
12. In Hyperterminal, select "Edit - Paste to Host". For each line pasted, you should get a "*READY" is response.
13. Copy the text above from "conf 1" up to and including "store" (7 lines, including the newline at the end)
14. In Hyperterminal, select "Edit - Paste to Host". For each line pasted, you should get a "*READY" is response.
15. In Hyperterminal, type "reset "
16. Switch off the RDAS
17. Disconnect the RDAS to serial cable from the PC to the OSD board


RDAS Post configuration

18. Connect the RDAS to serial cable from the PC to the RDAS
19. Open the RDAS Configuration Software
20. Switch on the RDAS
21. Enable the downlink option in the RDAS Configuration Software

The OSD board is now configured with the new display data.

Note: The instructions above refer to the RDAS Configuration Software when running on the Windows XP Operating System.


See Also

Hybrid Rocket Science, Hybrid Rocket Help Clinic, Amateur Hybrid Motors, Amateur Liquid Rockets, Guidance, Gimballed Motors, Launch Controller, UK Rocketry Vendors, UK Rocket Groups, UK Space Organisations