I'm looking for ideas. I really don't know what's out there, what is new tech or old.
I saw an HC12 Kinda think that might be what I'm looking for.
I want to tinker with as much small factor as possible with a GPS chip and rf transmitter to transmit its location and build a receiver that will display the lat/lon. I don't think I would require over a mile distance wide for the rf but if it does better than that, would be NICE. Obviously, an Arduino Nano or something else would do the parsing of the data on each end for lat/on.
And now the long story;
Over the last 6 months, I'd been tinkering and built a quadcopter from scratch. Was still learning to fly it.
My daughter wanted to see what it looked like through the FPV goggles. I shot it straight up and did a slow 360 rotation so she could see around. Was cool. Then panic set in as a wind burst blew it way off course. Since I'm flying now basically blind. Way up in the sky, you can't see what it's doing. It was near a field so I shut the motors off and let it drop out of the sky. Mind you, it's just over the treeline from my house and wasn't too far but, I didn't see where it landed. That was over a 2 weeks ago, still not found. I'm sure some lucky soul has a really nice drone with really nice onboard HD camera and GoPro mounted on top.
LoRa can do a mile easily. 10 miles, no problem. As long as there's no complete mountain in the way, buildings and so are generally no problem. Low power, too. To save battery (it's RF broadcast, still uses significant power) have it send its location every 5-10 mins or so.
Thank you, that's highly encouraging. I was thinking LORA but not too familiar with them. I had assumed they were used in setting up long range "Networks". So they are basically used as transmitters and receivers? Are there any legal issues I need to be aware of when using them? Would rarely be used. Just during flight and if lost... As long as I have a lat/lon I can retrieve it rather quickly and would be turned off for another days flight.
Plain LoRa (beware: different protocol, not compatible) is peer to peer. Comms can be encrypted (so only receivers with the key can understand the transmission), can be plain (and anyone listening within range can pick it up).
There are several bands in use - 433 MHz and two around 900 MHz. Here's a list of which bands are available in various countries (this are unregulated frequencies, basically open for anyone to use just with limits on power), I don't know how reliable the list is. There are modules for the 433 MHz and for the higher frequencies available.
marine_hm:
Are there any legal issues I need to be aware of when using them?
Not particularly, LoRa is a very effective at long range, so you only need to use 10mW, which is the licence excempt limit for ISM devices in most parts of the world.
Duty cycle limits can be an issue, but whilst in flight you can keep the LoRa transmissions very short, so sending a postion and height update ever 10 seconds or so is no problem. When the model is lost you then switch across to a low data rate and very long range mode.
LoRa devices are point to point, that just happen to be used in networks such as LoRaWAN.
Lots of stuff about using LoRa for tracking models and balloons will be found here;
For on indication of range in one of the worst locations to loose a model, a wet forest, read the "Lost in a (wet or dry) Forest.pdf" document at the above link.
And for a simple way of searching very large areas very quickly do read "How to Search 500 Square Kilometres in 10 minutes.doc" also at the above link.
