question on python version of 'transmitter' side

[on1arf]

Hi,

Last week I did some test with sending POCSAG messages using sx1278 (LoRa)-radio chip on Lilygo TTGO T-beam.
https://github.com/on1arf/sx1278experiments/blob/main/sendpocsag.py

As this device has an ESP32 (which includes wifi), it would like to try to write proof-of-concept code to use this platform as a DAPnet transmitter.

Two questions:

• is there already a python library that implements the 'transmitter'-side code of a DAPnet transmitter-site?

• if this does not exist, and I want to write it myself, is there a 'UAT' DAPnet server that can be used for development?
  This would avoid impacting the operational network if something unforseen would happen?

Thx.

Kristoff - ON1ARF

[on5mm]

Hello Kristoff,
interesting point. Since I've been doing some experimentation on LoRaAPRS with this boards, I had the same idea some time ago. I am convinced that it will work on hf site, but a bigger issue will be to transcribe the 'control intelligence' (i.e. client connection to core, organizing time slots, etc.) since all that Rust-Stuff (https://github.com/rwth-afu/UniPager) won't simply play on ESP32 in my opinion. Anyway, all the needed parts are available somehow, so sticking them together and adding the missing pieces should work.
Bringing up another instance of the core to do some experimentation with it is no big thing, but I wonder if that is really necessary, if we first concentrate on the transmitter part, there is no real callback-communication to the network and nothing should break.

Regards,
Michael ON5MM

[phl0]

Hej @on1arf
I can provide you with access to an experimental DAPNET master where you could experiment without affecting the productive system.
vy73 de Florian DF2ET

[on1arf]

Hallo Michael,

On 16.11.21 11:24, Michael wrote: Hello Kristoff, interesting point. Since I've been doing some experimentation on LoRaAPRS with this boards, I had the same idea some time ago.

yes, I think some interesting things we can do combining APRS (and especially the "Messaging" service on APRS) with LoRa, e.g. using LoRa as "backbone" layer to interconnect POCSAG-paging nodes bypassing the internet.

I am convinced that it will work on hf site, but a bigger issue will be to transcribe the 'control intelligence' (i.e. client connection to node, organizing time slots, etc.) since all that Rust-Stuff (https://github.com/rwth-afu/UniPager <https://github.com/rwth-afu/UniPager>) won't simply play on ESP32 in my opinion. Anyway, all the needed parts are available somehow, so sticking them together and adding the missing pieces should work.

Well, As the code is just a proof-of-concept, I wrote this code in micropython as it is an easy platform for development and experimentation. If this proves to be possible, then it is always possible to port it to another language if needed. (or just keep it running in micropython). B.T.W., I did find a blogpost on rust for the ESP32, but I have no experience at all with rust, so I have no idea how good it works.

Bringing up another instance of the core to do some experimentation with it is no big thing, but I wonder if that is really necessary, if we first concentrate on the transmitter part, there is no real callback-communication to the network and nothing should break.

Well, it's your platform, so it is up to you to descide if you trust your server to be good resiliant enough or not. In my book, I always consider any communication to be risky, so there is a risk that a bug sends some non-ascii characters, floods a TCP link, starts flapping 100 times a second or whatever. But, as said, that is up to you to descide. Or can I quickly set up a server locally on a box on my side? A docker images available on a pi4 would be nice :-)

Regards, Michael ON5MM

73 kristoff - on1arf

[on1arf]

Hej @on1arf I can provide you with access to an experimental DAPNET master where you could experiment without affecting the productive system. vy73 de Florian DF2ET

HI Florian,
That would surely interest me.

Let me know how I can contact it. :-)

Kristoff - ON1ARF

[on1arf]

Hi,

Hallo Michael,

I am convinced that it will work on hf site, but a bigger issue will be to transcribe the 'control intelligence' (i.e. client connection to node, organizing time slots, etc.) since all that Rust-Stuff (https://github.com/rwth-afu/UniPager https://github.com/rwth-afu/UniPager) won't simply play on ESP32 in my opinion. ....

It is me, or does this not compile on my ubuntu laptop (default ubuntu 20.04.3 LTS)

$ cargo build --release
(...)
Compiling backtrace v0.3.48
error[E0308]: mismatched types
--> /home/kristoff/.cargo/registry/src/github.com-1ecc6299db9ec823/lexical-core-0.7.4/src/atof/algorithm/bhcomp.rs:62:24

73
kristoff - ON1ARF

[ManoDaSilva]

Hi Kristoff! Fancy seeing you here too ;)

I'm also looking this up, but on the C/C++ Arduino environment, as RadioLib now implements it. I'm also thinking a DAPNET "local" parrot repeater might be interesting for indoor coverage, where internet access is not available :)

Some research on G4KLX's implementation on the MMDVMHost stack might prove useful too!

I'll keep you posted!

Manoel - ON6RF