Which RF device/protocol for this?

[Rx7man]

Hello, first post for me, been lurking a long time though.

I have an automotive application which will be requiring digital comms over a distance about 100 feet, but has to be really reliable at that distance.. Datarate can be low (1kbps would do fine).

So.. VHF, UHF, NRF34? 433mhz? LoRa? Bluetooth.. etc etc etc

Trying to keep cost down, though I know you get what you pay for

[kaz911]

One way or full duplex?
Moving or steady target?
High power or low power? (as in what is available to power radio etc)
Encrypted or does not matter?

I like TI's sub-1 ghz - does 100 feet without issue.

But if it is a hack - WiFi will do with some of the cheap WiFi modules.

[Rx7man]

Power consumption is largely irrelevant, steady target, though I will be forced to use an omnidirectional antenna (It would be nice if the antenna is kept within the plastic enclosure of 2"x3"x5", half duplex would suffice, encryption.. bonus, can't hurt right? 

There will be a fair bit of metal that could cause interference

Thanks.

You have a link to one of those TI devices?

[kaz911]

I think doing a design with sub-1ghz would be the nicest but I'm biased ...

http://www.ti.com/lsds/ti/wireless-connectivity/sub-1-ghz/overview.page

But WiFi should do the trick - and many use the ESP series board like below:

https://www.sparkfun.com/products/13678

[Rx7man]

There is of course no replacement for testing to see what works in the real world.. so I guess it comes down to what's a good place to start from... Is there one I should specifically avoid?

[Rx7man]

My initial idea was 433mhz, so that kinda helps push me in that direction..

Friend of mine sent me this link.. http://shop.in-circuit.de/product_info.php?cPath=22_28&products_id=174
To me it looks like a very expensive Arduino an off-the-shelf radio module and RS232/485 convertor..

As I'm looking and thinking, it would be nice to have some hardware pairing, which would put me towards bluetooth, but I think I might be a little limited until BT5 is readily available, the distance specs, etc on that looked pretty good