I wonder if the 3DR module of APM 2.6 / 2.8 would be suitable for a high altitude balloon.
arhab has been done using 300bps RTTY over a 10mW NTX2 transceiver at 433MHz
what method, protocol, bitrate and error correction is 3DR/APM using?
how much control does the (programmable) APM has over the 3DR transceiver?
could I transmit a bitstring linke with NTX2?
Could I get raw data from the receiver in order to apply advanced error correction
and make the balloon capable of receiving commands?
TIA
Tom
Replies
I don't think so I have also used NTX2B and an UNO.
The radio programming is done via mission planner for the 3DR radios, getting rid of the frequency hoping would be the issue. I am planning a HAB soon and several others already have with ardupilot and 3DR radios have a poke about the site and you will see!
Reading the code for the SiK modem I found that the 3DR applies (quite inefficient golay) error correction only to the packet payload and throws away any package not matching netid, length or crc. It may be reasonable to assume that kind of bad coding practice to be caused by too many people judging transmitters by their raw power and sensitivity ratings. A decent interleaved reed-solomon error correction could easily increase sensitivity by 10dB or more.
Tom