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MiniTiouner global performance - refresh time

Posted: Fri May 17, 2019 5:20 pm
by F6DZP
Hello,

I have seen some good question about MiniTiouner I2C performance that we can measure using "TestMyMiniTiouner" software.
The I2C performance depends of the design of the MiniTiouner and the USB port used on your PC.
a) if you test a MiniTiounerV1, a MiniTiounerV1, a MiniTiounerPro, you will see also differences.
b) if you change the USB port on the same PC you can see differences, if you change the PC you can see differences...

99% or 100% is the current value we can have using a MiniTiounerPro. A MiniTiouner V2 gives a lower result, I have tried to find why, changing the power supply, the VK200 filters, adding capacitor on the power lines, nothing changed. I think it is the I2C lines that have more noise, perhaps a Low value of some pico capacitor on one of the 2 I2C lines could change something? I have not yet tried.

The overall performance for rendering the measurement ( graphic, constellation, vu meters ...) are now shown directly on MiniTioune Measurement Panel at bottom right : this is the refresh time.
refresh time.jpg
refresh time.jpg (54.52 KiB) Viewed 580 times
the refresh time is the time spent between 2 displays of all measurements ( vu meter, constellations, oscilloscope, derotator scan..)
in the perfect world, this time should be 100ms.( the time I ask fo the measurement loop clock)

Using a MiniTiounerPro with my old desktop PC, receiving and decoding a SR250 signal, I have a result between 220ms and 240 ms using a MiniTiounerV2, I have a result of 115ms to 120 ms using a MiniTiouner Pro.
Using a recent laptop or my new desktop the refresh time is 105 to 110 ms with a MiniTiounerPro.

this refresh time doesn't affect the video or locking/receiving capacity if it is not too high, but for a good comfort it should be "reasonable" to have it under 300ms.

using a Pipo or a Shuwi 10" Tablet I have a refresh time of about 180 ms to 190 ms (using a MiniTiounerPro).

Jean-Pierre F6DZP

Re: MiniTiouner global performance - refresh time

Posted: Fri May 17, 2019 6:36 pm
by g0mjw
Interesting. I have three units here, one scored 75%, one 68%, the other 40%. The best is a V2 prototype on the old PCB, then the first V2 with no LNA, then the V2 with the the OLED and LNA. The PCB was not designed with high speed I2C performance in mind, it could have been had that been a requirement. Clock and Data take different routes and are not transmission lines. There are several vias and potential to pick up noise.

Mike

Re: MiniTiouner global performance - refresh time

Posted: Sat May 18, 2019 9:10 am
by G4GUO
FWIW I just tested 30 Minitiouner-Express units and I get values between 60% and 88%
These units are assembled by a robot so should be identical.

- Charles

Re: MiniTiouner global performance - refresh time

Posted: Sat May 18, 2019 8:39 pm
by 2W0ODS
g0mjw wrote:
Fri May 17, 2019 6:36 pm
Interesting. I have three units here, one scored 75%, one 68%, the other 40%. The best is a V2 prototype on the old PCB, then the first V2 with no LNA, then the V2 with the the OLED and LNA. The PCB was not designed with high speed I2C performance in mind, it could have been had that been a requirement. Clock and Data take different routes and are not transmission lines. There are several vias and potential to pick up noise.

Mike
Have you run the test with the OLED disconnected, would be interesting to see if that makes any difference.

Re: MiniTiouner global performance - refresh time

Posted: Mon May 20, 2019 9:15 am
by F6DZP
yes, with or without OLED should show a difference.

Jean-Pierre F6DZP