Hi,
I would like to use a 433 LRS system with an FPV plane (X8) but the alternative 3DR 900 Mhz telemetry hardware is not permitted in Germany even if you have an Amateur Radio Licence as I do. The 800-1000 Mhz band is widely used by mobile phones and 3G/4G systems.
Has anyone had any success using the 2 way link on 433 LRS systems like, for example, the ImmersionRC system for APM telemetry. Thinking about it, even if the software could be made to work for the telemetry downlink, the uplink would still have to time share with the RC control signals so I am not sure how effective it would be.
Or alternatively, is there any way to allow the 3DR 433 telemetry hardware to be in use with 433 LRS without massive adjacent channel interference? I have tried a very short experiment with a HK openLRS system but without much success.
In Germany, large parts of the 430-440 Mhz/70Cm amateur band are available for use by telemetry but any solution would need to be legal.
I expect someone has already tried this but I cannot find anything in a forum search. Any help or pointers gratefully received.
Regards
Alan
Replies
Hi, I've made a custom firmware in order to make OpenLRS work well with APM, so far I've gone 10 km away with full APM telemetry. No need to modify anything on APM, no need to ctrl-T, all parameters are sent correctly, everything can be modified even during the flight, such as changing PID parameters or sending a new mission. Full 19200 bauds for APM, and of course RC is sent as well.
Described here :
http://www.itluxembourg.lu/site/
Discussed here :
http://www.rcgroups.com/forums/showthread.php?t=2037442
At the moment i am working on getting the APM Mavlink to run smoothly over OpenLRS. It works but needs some tweaking because the datarate cannot be as high as mavlink needs. If you set the OpenLRS telemetry to 9600 baud and the telemety in the APM also to 9600 you can connect with mission planner using CTRL + T. This way it won't load all the parameters.
Also look at the SR0 / SR3 (if you use UART2) settings
Jay,
Thanks for the reply. it is true that LRS do not speak Mavlink natively but I am not certain what is purpose of the two-way function of LRS systems - I am assuming telemetry. I will have to look into that.
Regards
Alan