ALPHA 2022 11 02

UA0LMC
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Re: ALPHA 2022 11 02

Post by UA0LMC » Wed Nov 02, 2022 11:21 pm

VK3KYY wrote:
Wed Nov 02, 2022 11:09 pm
BTW.

u-centre does not seem to support decoding of Chinese satellite data.
Tools -> Preferences -> Generic -> NMEA Custom BDS Talker ID
Set it to BD
(IIRC it's empty by default).

Some GNSS modules, including u-blox, report BeiDou as i.e. $GBGSV. Some others - as $BDGSV, which is the case.

VK3KYY
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Re: ALPHA 2022 11 02

Post by VK3KYY » Wed Nov 02, 2022 11:31 pm

UA0LMC wrote:
Wed Nov 02, 2022 11:21 pm
VK3KYY wrote:
Wed Nov 02, 2022 11:09 pm
BTW.

u-centre does not seem to support decoding of Chinese satellite data.
Tools -> Preferences -> Generic -> NMEA Custom BDS Talker ID
Set it to BD
(IIRC it's empty by default).
This did not seem to make any difference.

I will need to investigate why the CPS has a problem.

Just disabling the NMEA if there was any USB serial traffic, helped the CPS, and I tested with some other PC applications which didn't send any data to the USB, and they worked fine.

However, I agree, disabling NMEA if there is any USB serial traffic from the PC no good.

Unfortunately the CPS protocol is very simple, with just single letter commands "R" read, "W" or ""X" for write and "C" for command.

So even if I only stop NMEA if R,W,X, or C is sent as the first character from the PC, there is chance that some PC applications may send these characters and it would still stop NMEA output.

Also, probably MMDVM Host and BlueDV will send different data, to activate hotspot mode, but I can't remember the protocol

So its probably not practical to disable NMEA output automatically, as I can't control what 3rd party PC applications send or what MMDVMHost or BlueDV sends

Operators will need to disable NMEA output if they want to use Hotspot mode of use the CPS

VK3KYY
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Re: ALPHA 2022 11 02

Post by VK3KYY » Wed Nov 02, 2022 11:37 pm

BTW.

The older UV380/RT3S and MD9600 GPS modules send different data

Older sends

$GPxxx newer send $GNxxx I now check for ***RMC and ***GGA etc

Only for GPGSV and BDGSV do I check all the string, so that I know if its a Chinese of non-Chinese satellite.

I am also currently not displaying the fix type (2D / 3D) but I am already decoding this.

UA0LMC
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Re: ALPHA 2022 11 02

Post by UA0LMC » Wed Nov 02, 2022 11:50 pm

Probably GNSS module firmware is different. I even have an older module based on the same AT6558 chip which does not support BDS at all.

AFAIR there was an update to NMEA protocol. Now it sends $GNGGA, $GNRMC etc. for multi-GNSS modules.
The SVs are the same, as per GNSS: $GPGSV, $GLGSV, $GAGSV and also $GBGSV or $BDGSV.

VK3KYY
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Re: ALPHA 2022 11 02

Post by VK3KYY » Thu Nov 03, 2022 12:27 am

I am now parsing

$XXGGA
$XXRMC

$GPGSV
$BDGSV

I don't think any of the modules fitted in the MD9600/RT90 / UV380/RT3S send $GLGSV or $GAGSV or $GBGSV

I could possibly add a data value to indicate the second letter of GSV is L or A or B or P but I don't think it makes any difference to the operation of the radio.

Even separating BD and GP satellites is probably unnecessary, and I should combine these data arrays, and perhaps just use a 'type' code with the satellite

U-Centre is currently showing American flags for all the satellites, but I'm not sure whether this is correct, or whether some are GLONASS or Galileo etc

Perhaps these modules only receive USA and Chinese satellites

UA0LMC
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Location: Vladivostok, Russia

Re: ALPHA 2022 11 02

Post by UA0LMC » Thu Nov 03, 2022 1:56 am

ATGM-336H is GPS/BDS-capable, so parsing these messages should be enough. Also $xxGSA and $xxVTG messages may be of some interest.
If somebody decides to replace the module with a different one of the same form-factor - then it may not display SVs correctly. However, xxRMC will be more or less the same, so lat/lon and time should still be available.

As for the flags - either u-center ignores $BDGSV messages or there is no BeiDou SVs available.
I've attached a screenshot. Don't mention the reception quality - it's the same ATGM-336H module as in RT-3s but with a good external antenna.

Also some ATGM-336H versions are capable of QZSS - but it displayed as SBAS satellites with a strange (non-existing?) numbers.
Attachments
u-center.png
u-center.png (14.98 KiB) Viewed 1118 times

S58SMS
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Re: ALPHA 2022 11 02

Post by S58SMS » Thu Nov 03, 2022 5:05 pm

Hello.

Does anybody own md380 and baofeng or gd77. I own both and did a test. Md380 has much worser rx reception than baofeng 1801 does. I did a research on uhf and vhf. On uhf it works more or less ok, but on vhf, its a really big difference. Any suggestions. Will be possible to calibrate it?

Br

EU1AEQ
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Re: ALPHA 2022 11 02

Post by EU1AEQ » Fri Nov 04, 2022 6:45 am

Hello.
Why is there a link to the October 19 version in the first message of the topic?

OE1MWW
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Re: ALPHA 2022 11 02

Post by OE1MWW » Fri Nov 04, 2022 8:09 am

S58SMS wrote:
Thu Nov 03, 2022 5:05 pm
Hello.

Does anybody own md380 and baofeng or gd77. I own both and did a test. Md380 has much worser rx reception than baofeng 1801 does. I did a research on uhf and vhf. On uhf it works more or less ok, but on vhf, its a really big difference. Any suggestions. Will be possible to calibrate it?

Br
My Retevis RT-3S (same as MD380, just other labels on housing) and my GD-77 - with exactly same brand & type of antenna, the RX sensitivity
on VHF & UHF is roughly the same. Consider, what can you expect from a 150 dollar (end user!) device ?
There is not much room for quality control, or to produce equal precise specifications for each device. Unfortunately... :-(

'calibration' is the term of adjusting a measurement info compared to a given standard: Example: scale/display shows 5 watt - measured output
on a calibrated watt meter is the same, if not, the display/scale must be adjusted accordingly, so it will be kind of 'calibrated' too.
Btw., I don't think sensitivity of a MD380 can be adjusted.
73's de OE1MWW
Wolfgang

VK3KYY
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Re: ALPHA 2022 11 02

Post by VK3KYY » Fri Nov 04, 2022 9:18 am

EU1AEQ wrote:
Fri Nov 04, 2022 6:45 am
Hello.
Why is there a link to the October 19 version in the first message of the topic?
My mistake

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