After tinkering with OpenLRS, an open source long range system for radio control, I began wondering if it would be possible to use the same modules as them (RFM23BP, 1w 433MHz transceiver) to create a very long range, albeit slow, network link. The module's maximum bitrate is 128kbps losing quite a bit of sensitivity, so streaming video would be out of the question, but it is an interesting idea nonetheless.
Since I now nothing about implementing IP I ask you guys, could it be possible to create a transparent ethernet-spi-433mhz-spi-ethernet bridge?
Perhaps not with 8 bit mcus, but rather with an arm powered board, an esp8266 or even a raspberry pi.
I know that sending a continuous data stream on 433mhz at such high power levels is not legal on some countries, but here the frequency is open and I'll be trying this on a desert anyway, to have less obstacles.
Encapsulating network packets into a serial stream was the way to access the Internet when I began with it. The necessary tool is called PPP. I don't know any implementation of it for the Arduino platform but every Linux computer (so the Raspberry Pi for example) can use this without any problem.
Thanks, I'll check on Raspberry Pi forums then, although perhaps I'll use a smaller ARM board for it.
I guess a good way of trying this would be to use the legacy Age of Empires 2 first in serial connection mode and then on LAN mode, to see when the UHF link works better.
I did something like this using HC11 radios which arnt the same as yours but are similar in that they operate at 433 Mhz and are fed with ttl serial data.
One end was connected to a PC running Ubuntu Linux acting as a router and the other end to an old PC running XP using Slip for windows.
It works but is staggeringly slow, and the only apps that would work reliably were FTP,SMTP and ping.
HTTP was problematic and would often time out.
The major problem is the default size of an IP Datagram is between 1400 - 1500 bytes, but these small radios cant handle such large data packets and corrupt the data, so you have to reduce the MTU to something much smaller like 256 which is the default for Slip.
It then works , but with the performance of a bad dial up modem.
Whats the intended application for this.
Thank you for your answer!
The application for this is simply learning by fooling around. Although I'd love to make a reliable ultra-long range non line of sight fast internet connection, I know that is well beyond my capacity and the resources I have available, so I just want to maje a small "proof of concept" for fun.
You cant make an ultra reliable long range non line of sight radio link at 433 Mhz and at the same time transmit hi rate data.
Thats simply not possible with the simple types of modulation schemes that the common cheap radios use.
But as a learning exercise, its fun to play around with.