Preview of my wireless modem development

Here is a preview of my long range wireless modem.

It's based on a Radiocrafts 868Mhz module (RC1180HP) with 450mW RF output power and good receiver sensitivity.

I'm going to use this for modem telemetry and antenna tracking, one in groundstation and one in the airframe

It has the following features:

1x LCD 102x46dots

4x Buttons

1x MicroSD slot

3x analog to digital inputs

1x I2C

1x SPI (if LCD is not used)

1x RS232 (TTL)

2x Timer outputs (used to connect a 4017 to drive servos)

4.5 to 32volt DC input

Dimensions are 44mm x 55mm x 5mm

More info will be added later.....and yes it will be open-source, I will share all design info if you want....


Here you can find the schematics: RC1180HP-Modem.pdf

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  • Interesting project as it helps me in getting on the RF side of FPV, something that interests me a lot. Would be a great help if the schematics and board files are made available. Would be interested in two boards plus any indication where to get the components that are not available from any electronics store. Maybe a kit of parts if that is possible.

  • @Mark, thanks!
    @Ahmad, thanks!
    @Johann, range is highly depending on antenna system and regulations you want to meet, but more than 5Km LOS must be possible.
    @abey, that's why I like this statement of the Radiocarft datasheet :"The use of RF frequencies, maximum allowed RF power and duty-cycles are limited by national
    regulations. The RC1180HP-RC232 is complying with the applicable directives within the
    European Union when used within these limitations."

    The legal discussion is always a interesting part, using the radiocrafts module it's upto the user, but it's certified so it could meet the regulations which is good, the +27dBm is the maximum RFoutput but is configurable by the user.
    Even a +10dbm output with 100% duty and a high gain yagi antenna is not legal because regulations are about ERP ;-)
    Before I used a Wi232 module at +15dBm (32mw) and got a solid link with 9600baud at 4Km LOS, but this was with a 12 element yagi at the ground station pointed to the plane.

    If there is interest in this project I can upload the schematics and board files, I think the board layout will be ready next week so I will place the order for about 10 boards next week, if more are needed let me know. I think the price for one board is around €10,- but depending on the quantity.
    I hope there is some interest for this project because code has to be done from scratch, so help is very welcome !
  • That's 6 minutes. Any sensible flight is going to be longer so this will be a problem. For example, the 6 minute transmission time per hour is hardcoded in the XBeePro 868. It wont transmit anymore than that, so that makes it pretty much unusable for UAV purposes.
  • The law says 10% averaged over 60 minutes, I'm guessing that's what this one does since it's certed.
  • Re: legal issue, does it mention a 10% or 1% maximum duty cycle? Because it's a very common restriction in this kind of frequency for anything above 10mW.
  • Data sheet gives range of 3-5Km LOS.

  • It's a Norwegian company and the module shown above is said in its data sheet to conform with EU R&TTE directive (EN300220, EN301489, EN60950). So looks like we are good to go in Europe.

  • Interesting. What would be the RF baudrate? How legal do you expect it to be in Europe (regarding the RF laws)?
  • Excellent and best work....
  • Developer
    Nice! Thanks for publishing as Open-Source, flexible design with cool options.
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