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cyoung / stratux

Aviation weather and traffic receiver based on RTL-SDR.
BSD 3-Clause "New" or "Revised" License
1.05k stars 360 forks source link

Test new hardware #122

Closed cyoung closed 8 years ago

cyoung commented 8 years ago

It "looks" like it's the NooElec dongle - is it?

Anyone want to try the kit? Saves a few bucks.

http://amzn.com/B016QP0FXO

bradanlane commented 8 years ago

I'm already heavy with hardware as I was experimenting with components for the "under $50" package (including a battery).

The bundle from that link doesn't include a battery so it's about a $10-$12 savings from the original shopping list.

rgutlon commented 8 years ago

Certainly looks like the SDR is private labeled from NooElec. http://amzn.com/B017AFPHAK

cyoung commented 8 years ago

Who knows - if it is then $10-12 is something.

bradanlane commented 8 years ago

True. A buck is a buck and pilots are notoriously cheap :-) I should know. I am one !

Nearly all the savings can be had right here - http://amzn.to/1H5tGVj

They take 2-3 weeks to arrive but they are the same SDRs.

cyoung commented 8 years ago

Have you been able to do a side-by-side with the NooElec?

I asked Vilros if it's the "same" as the NooElec dongle. They said "No, this is a Vilros brand RTL-SDR, basically the same as NooElec, but manufactured by Vilros."

bradanlane commented 8 years ago

A "side by side" comparison would mean flying two identical systems which I do not have.

However, a visual examination of the internals show they have the same boards with the same chips in the same places with the same PCB routes.

cyoung commented 8 years ago

Fair enough, I'll order up one at some point and try it.

bradanlane commented 8 years ago

I've got six of them :-)

cyoung commented 8 years ago

So you have a NooElec and one of the cheap ones?

I just plug them in and do the rtl_sdr | dump978 command at the same time, send the output to diff files for each, and count the number of messages in each.

bradanlane commented 8 years ago

Like I said, I visually compared these SDRs. I looked closer at all of the SDRs I have and I actually have units from three different vendors. They have different marking on the blue plastic case but the boards inside are identical.

The flying I do does not allow me to do in-flight testing. (No safe place to have a Stratux that isn't completely self contained.)

bradanlane commented 8 years ago

I did perform signal to noise comparisons, using an R820T as my base reference. All of the SDRs I have which are marked at R820T2 have better results that the R820T. I also tested against an E4000 SDR.

depletedcaliber commented 8 years ago

i have been using this one: http://www.aliexpress.com/item/1pc-Wholesale-Mini-2-USB-TV-Stick-DVB-T-RTL-SDR-Digital-TV-Receiver-USB-RTL2832U/32333687109.html

working pretty well so far.

cyoung commented 8 years ago

Great, but looking more for quantitative results as different setups can easily be evaluated with side-by-side message rate comparisons.

 rtl_sdr -d x -f 978000000 -s 2083334 -g 48 - | ./dump978 |
depletedcaliber commented 8 years ago

I can pick up 2 towers from my 1090 antenna setup for piaware in my attic. I can only compare with an rtl-sdr blog dongle and the cheap aliexpress one as those are the only distinct models I have.

I can put a splitter(if i can find one) and try both dongles simultaneously and see if i can get some message rate metrics. I don't have a nooelec tuner though.

depletedcaliber commented 8 years ago

I ran the two commands, below, in two terminals. It will count the number of lines printing out the average rate each second, with the label N.

The rtlsdr-blog dongle is configured to put 5v bias tee on the feed up to a low noise amp, then antenna.

rtlsdr-blog     \___<two way splitter>_____________<LNA><ANTENNA>
blue dongle  /
rtl_sdr -f 978000000 -s 2083334 -g 48 -d 0 - | ./dump978 | pv -la -N RTLSDR-BLOG > /dev/null 
rtl_sdr -f 978000000 -s 2083334 -g 48 -d 1 - | ./dump978 | pv -la -N BLUE  > /dev/null

Average for both was about 3.61-3.91 lines per second. Blue seemed to be always head by 0.10 lines. I only really watched it for 5 or so minutes. Not entirely a large sample size.

Not completely scientific, but enough to see the blue $8 dongle was at least the same performance it seemed as the rtlsdr one.

i can redo it and keep the output and diff them to see if there is an extra message or so .

cyoung commented 8 years ago

Excellent, thank you.

heelix commented 8 years ago

Not sure if we want to consider this new hardware or not - but I've been getting this to run on the pi zero. Definitely in the spirit of driving the costs down. Since it is the older ARM 6 core, rather than the 7 like the newer pi, it does require a few different hoops, however. Use this thread for testing/progress on the zeros?

bradanlane commented 8 years ago

@heelix, which powered USB hub did you go with?

heelix commented 8 years ago

@bradanlane

This is what I picked up from Amazon.

http://www.amazon.com/gp/product/B011K5XOCO

I have a bunch of cable parts taking the slow boat from China where I should be able to do it for less, but don't have those in hand yet.

bradanlane commented 8 years ago

We keep filling that "slow boat from China" :-) I'm running Stratux on one of these:

http://m.aliexpress.com/item/32448079125.html

I haven't messed with an AHRS on it since I'm focused on one of two Stratux configurations - single SDR; and single SDR + GPS.

heelix commented 8 years ago

I'm attempting to port to one of the $5 zeros, which does take power via micro-usb.

http://www.microcenter.com/product/457746/Raspberry_Pi_Zero

Other than the CPU being like the earlier generation, I can power at least one dongle without assistance. I've plugged in two radios and seen both light up, but my Bride wanted to watch some TV before I had a chance to see if it was working. (No power LED on the zeros, so a bit harder to tell if one is having issues or not)

Got a bag of micro-usb headers, etc. showing up in January. I'm planning to solder up my own splitter/hub.

bradanlane commented 8 years ago

Just an FYI: you'll need a "hub" chip. You can not just wire USB ports in parallel. (I tried)

heelix commented 8 years ago

Got that coming too :) but the plan was more for power routing to each of the USB devices than dealing with the data. Looking to shim the USB with the power going to a different power source than through the mainboard.

On Tue, Dec 8, 2015 at 4:09 PM, bradanlane notifications@github.com wrote:

Just an FYI: you'll need a "hub" chip. You can not just wire USB ports in parallel. (I tried)

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/122#issuecomment-163033802.

cyoung commented 8 years ago

Use this thread for testing/progress on the zeros?

Please do!

Since it is the older ARM 6 core, rather than the 7 like the newer pi, it does require a few different hoops, however.

Probably should work fine just recompiling the binary. Maybe decrease replay buffer sizes or cap the max number of connected clients. What have you found so far?

skypuppy commented 8 years ago

The older A6 core doesn't have hardware floats, IIRC. But that's been a while. So calcs will take considerably longer for sin, cos, etc.

Skypuppy

On 12/08/2015 08:28 PM, cyoung wrote:

Use this thread for testing/progress on the zeros?

Please do!

Since it is the older ARM 6 core, rather than the 7 like the newer
pi, it does require a few different hoops, however.

Probably should work fine just recompiling the binary. Maybe decrease replay buffer sizes or cap the max number of connected clients. What have you found so far?

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/122#issuecomment-163086860.

jtremolo commented 8 years ago

Any progress on using the RPi Zero?

heelix commented 8 years ago

Yes. Got it running, but did not have a chance to get in the air with it before it was killed off by my crappy soldering skills. I've not another one I need to pick up, and will try again.

On Wed, Dec 23, 2015 at 9:18 AM, jtremolo notifications@github.com wrote:

Any progress on using the RPi Zero?

— Reply to this email directly or view it on GitHub https://github.com/cyoung/stratux/issues/122#issuecomment-166922259.

cyoung commented 8 years ago

Vilros SDR works about the same as the NooElec and has a better antenna.

Pi Zero works fine @jtremolo. Used an external (powered) USB hub. There seemed to be some USB hub quirks to deal with, didn't try anything other the one that was one hand.