DIGI modes and ESPRI
Added 2025-05-26 19:07:09 +0000 UTCA while ago I was really close to get the standalone AFSK modem out of ESPRI project.
Here is the WIP PR: https://github.com/kamilsss655/ESPRI/pull/65
However I was getting unreliable results, so I paused the work on this feature.
Completing it would be huge as it would allow to turn ESPRI into digital radio modem with WEB interface.
This in result would allow ESPRI to have features like:
advanced messaging including mesh, encryption, autentication, routing etc
file sharing capabilities over radio
radio - internet gateways
and likely all other kind of things users could come up with
The issue was that sometimes I wouldn't receive the correct bitstream. I was not really able to find the source of this issue in the code. Perhaps the issue was not the code?
As it turns out there were some developments recently around UV-K5 filtering in regards to use with digital modes done by Mobilinkd: https://github.com/mobilinkd/uv-k6-digital-mod/blob/master/UV-K6.ipynb
Where they have done some audio path hardware modifications and also firmware audio filtering modifications.
I am considering introducing a new DIGI modulation mode (with audio filters turned off) to the UV-K5 firmware and retest the ESPRI AFSK modem.
I've run my ESPRI AFSK PR by the several large language models and they all confirmed that the code looks good and is compliant with what commercial grade DSP modems do.
So perhaps the only thing left to do is to disable the audio filters on K5..
Stay tuned for more!
Comments
Yea I agree Dan. If I can make it work (and this was my main goal behind ESPRI project), such functionality could be had for 1/5th of the price of the device you mentioned. In fact it would be even better because you wouldn't need any specialized client. With ESPRI you could use a web browser on a phone. However I haven't gotten time lately to go back to it and retest the AFSK with K5 disabled filters, but it is on my long term list. I do plan to revisit this topic though.
kamilsss655
2025-06-21 13:46:13 +0000 UTCRecently VGC & BTech released the VGC VR-N76 and the BTech UVPro, these radios have a built in AFSK KISS TNC that is accessed over Bluetooth, the Amateur community in the US is quite impressed with the radio as it connects to APRSDroid and WOAD quite easily. I think if ESPRI could provide those capabilities for any Quansheng / Baofeng type radio I would think the market could be quite big (maybe less costly than Mobiinkd ?) .
Dan H
2025-06-21 11:01:25 +0000 UTC
