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Re: Future support for STM32F1 boards?
Posted: Mon Jan 29, 2024 1:58 pm
by MW0MWZ
G8SEZ wrote: ↑Mon Jan 29, 2024 1:26 pm
AC8OB wrote: ↑Mon Jan 29, 2024 12:36 pm
I now have YSF working again with 4.2.0 beta. The change that fixed it was setting LowDeviation to 1 in the MMDVMHost settings. Mode on my FT-3D is set to DN. I'll go away and research what this does.
DN and VW mode have the same modulation parameters but use different codecs and hence the packet contents are different. DN uses AMBE, VW uses IMBE which is what P25 radios use, it's older than the AMBE variants and has a higher speech bit rate on air.
The radio does not change the inner and outer 4FSK deviation values, as far as I know this only affects the deviation on FM with 5kHz for FM and 2.5kHz for FM-N. The 4-level FSK deviations are +/-600Hz and +/-1800Hz with GMSK filtering in the modulator.
On top of that, the Yeasu radios (at least FT-2D and before) also had wide/narrow modes for deviation (in addition to DN and VW), all of that has to match up between MMDVMHost and what you set in the radio.
Re: Future support for STM32F1 boards?
Posted: Mon Jan 29, 2024 9:42 pm
by G8SEZ
MW0MWZ wrote: ↑Mon Jan 29, 2024 1:58 pm
G8SEZ wrote: ↑Mon Jan 29, 2024 1:26 pm
AC8OB wrote: ↑Mon Jan 29, 2024 12:36 pm
I now have YSF working again with 4.2.0 beta. The change that fixed it was setting LowDeviation to 1 in the MMDVMHost settings. Mode on my FT-3D is set to DN. I'll go away and research what this does.
DN and VW mode have the same modulation parameters but use different codecs and hence the packet contents are different. DN uses AMBE, VW uses IMBE which is what P25 radios use, it's older than the AMBE variants and has a higher speech bit rate on air.
The radio does not change the inner and outer 4FSK deviation values, as far as I know this only affects the deviation on FM with 5kHz for FM and 2.5kHz for FM-N. The 4-level FSK deviations are +/-600Hz and +/-1800Hz with GMSK filtering in the modulator.
On top of that, the Yeasu radios (at least FT-2D and before) also had wide/narrow modes for deviation (in addition to DN and VW), all of that has to match up between MMDVMHost and what you set in the radio.
Yes, which doesn't make any sense, but maybe it was some sort of thing put in by firmware engineers who didn't actually understand the RF aspects.
Re: Future support for STM32F1 boards?
Posted: Mon Jan 29, 2024 11:33 pm
by AC8OB
There is definitely some interaction on my FT-3D.
Radio FM deviation WIDE, YSF LowDeviation 0 = works.
Radio FM deviation NARROW, YSF LowDeviation 0 = NOT working.
Radio FM Deviation NARROW, YSF LowDeviation 1 = works.
Radio FM deviation WIDE, YSF LowDeviation 1 = NOT working
And my BER is in the green
I have yet to try VW, coming from a broken FT-70D which only had DN. I normally have 70cm set for narrow deviation so I'll leave LowDeviation at 1.
Re: Future support for STM32F1 boards?
Posted: Tue Jan 30, 2024 5:12 pm
by G8SEZ
AC8OB wrote: ↑Mon Jan 29, 2024 11:33 pm
There is definitely some interaction on my FT-3D.
Radio FM deviation WIDE, YSF LowDeviation 0 = works.
Radio FM deviation NARROW, YSF LowDeviation 0 = NOT working.
Radio FM Deviation NARROW, YSF LowDeviation 1 = works.
Radio FM deviation WIDE, YSF LowDeviation 1 = NOT working
And my BER is in the green
I have yet to try VW, coming from a broken FT-70D which only had DN. I normally have 70cm set for narrow deviation so I'll leave LowDeviation at 1.
It suggests to me that the 4FSK modulation in the FT-3D is either different between the FM modes which should not be the case, or the digital data stream has a field set to something different and for some reason the LowDeviation setting in Pi-Star matters in interpreting it.
Probably need to look at the Pi-Star/MMDVM source and work out what changes with YSF and LowDeviation 0 and 1.
Re: Future support for STM32F1 boards?
Posted: Tue Jan 30, 2024 6:55 pm
by AC8OB
G8SEZ wrote: ↑Tue Jan 30, 2024 5:12 pm
It suggests to me that the 4FSK modulation in the FT-3D is either different between the FM modes which should not be the case, or the digital data stream has a field set to something different and for some reason the LowDeviation setting in Pi-Star matters in interpreting it.
The wide/narrow setting appears to be independent for VFO A or B. Also it's stored to each memory.
Probably need to look at the Pi-Star/MMDVM source and work out what changes with YSF and LowDeviation 0 and 1.
I can't remember back 4 or 5 years when I first played with this with the FT-70D whether that setting was there in the MMDVM config. But that and the radio features may explain why a lot of folks (me included) get a new radio and find it doesn't work with their hotspot. The friend I bought my 3D from now has a 5D so I'll get him to do some comparisons...