<kristianpaul>
yeah, same situation as my self :-S
<kristianpaul>
i guess osgps never got track as i was feeding it with complex data
<kristianpaul>
even after sample 40Mb of data
<kristianpaul>
also this gps-sdr from CTA es kinda slow and cpu consuming, was very wise from him to swtich to scilab :-)
<wpwrak>
so what's the plan then ? wait for Artyom to fix things on his side ?
<kristianpaul>
no of course not
<kristianpaul>
also his side have its complexity that he only understand
<kristianpaul>
i still on my namuru debugging, afaik cant make carrier nco to work..
<kristianpaul>
once i get it work, the accumulator should start to work
<wpwrak>
ah, so your troubles are still in earlier processing stages than his. i see.
<kristianpaul>
with namuru yes
<kristianpaul>
but in full software processing kinda same
<kristianpaul>
but i had same issues as heen before with the acquisition module, i got prn code detection but couldt lock it..
<kristianpaul>
that was with osgps
<kristianpaul>
i soft mode to put it a name
<kristianpaul>
he was very kind to sent my hist vhdl namuru code
<kristianpaul>
i discover i missed a state for the time base counter on my verilog code
<kristianpaul>
fixed now, i'll try as soon sitesis finish
<wpwrak>
cool. that's probably a good bug to fix ;-)
<kristianpaul>
well, i depend may be xst asumed what he wrote in the code and i specify
<kristianpaul>
and sadly it wast related to my carrier nco stuckness...
<kristianpaul>
and i'm using carrier_nco code as it is..
<kristianpaul>
so the error should be in higher layers..
<wpwrak>
the harder the bug to fix, the greater the glory ;-)
<qi-bot>
[commit] Werner Almesberger: ptrude/: functions for path stretching and calculation of proportional length (master) http://qi-hw.com/p/cae-tools/7ef6269
<qi-bot>
[commit] Werner Almesberger: ptrude/: changed extrusion from xy path to xz path; variable number of faces (master) http://qi-hw.com/p/cae-tools/ee63445
<Artyom>
But can you use higher sampling frequency?
<kristianpaul>
yeah, in real mode
<kristianpaul>
16.694Mhz of sampling
<kristianpaul>
same IF, 2 bits per sample
<kristianpaul>
i switched to that mode now
<kristianpaul>
but all went i can try complex agains namuru
<kristianpaul>
btw i checked you code, i added a codition to the counters that i missed, but of course time_base was working before
<kristianpaul>
and i still get the carrier nco stuck :(
<Artyom>
In my front-end I also have complex-data output. I have IF=2.42MHz Sampling=16MHz and bandwidth=4.2MHz. When I work with osgps, I just throw away all Q-samples and use only I-samples.
<kristianpaul>
Artyom: every sample 4 bits at 2.048 MSPS at 8.192 Mhz sampling clock in other words
<kristianpaul>
still using maxin right?
<Artyom>
yes
<kristianpaul>
you trought away all Q-samples?? but what happened if carrier mas in that?
<kristianpaul>
i may be wrong but i think is no always exactly this guess
<kristianpaul>
s/carrier/C/A
<kristianpaul>
s/guess/asumption
<Artyom>
what do you mean "what happened if carrier mas in that?". Can you explain in more detail...
<kristianpaul>
ah, moment you work with GLONASS not GPS right?
<kristianpaul>
in GPS L1 signals there is a P-code and C/A code
<Artyom>
I work with both. But now as I use osgps+namuru I work with GPS only. Later It will be easy to switch to GLONASS
<kristianpaul>
on is in phase other quadrature, (dont remenber wich on is who..)
<Artyom>
Yes, In GLONASS the same thing
<kristianpaul>
oh nice
<kristianpaul>
i may may be wrong but i undertood that processing just Q for example you cant get the P-code
<kristianpaul>
but as i said, is a _guess_ for me i never dig in to
<Artyom>
No, this is wrong
<kristianpaul>
:-)
<Artyom>
:(
<Artyom>
In receiver there is another meaning in quadrature channels
<Artyom>
We use quadratures in receiver when we work with signals with unknown phase (like it is in GPS/GLONASS/COMPASS/GALILEO)
<kristianpaul>
ah
<kristianpaul>
well. i'll check more theory about this later
<kristianpaul>
btw before i leave cause i travel to work like 2hr and i have a meeting in the morning..
<kristianpaul>
the carrier phase register in namuru just need to be written once isnt? well at least for initilization, later i may be ajusted acording to doppler etc..
<kristianpaul>
i think i'll write a testbench for it, and debug it individually..
<Artyom>
which exactly register are you asking about?
<kristianpaul>
CODE_NCO
<kristianpaul>
and  CARRIER_NCO
<Artyom>
during acquisition you set CODE_NCO to a fixed value
<kristianpaul>
yes
<Artyom>
and CARRIER_NCO is changing according to current doppler-bin (where we search the signal)
<Artyom>
And during tracking we always change their values
<Artyom>
both CODE_NCO and CARRIER_NCO
<kristianpaul>
but then CARRIER_MEASUREMENT will not change its value over the time if i dont change the CARRIER_NCO ?
<kristianpaul>
cause i'm initializing both CODE_NCO and CARRIER_NCO with fixed values
<kristianpaul>
if i read CODE_MEASUREMENT it looks like is changing vauet but not the case for CARRIER_MEASUREMENT..
<kristianpaul>
that let me thing something wrong was happening with the carrier nco module..
<Artyom>
may be, I can't tell you exactly as I didn't dig so far. I only tried to control tracking loops. And CODE_MEASUREMENT and CARRIER_MEASUREMENT are used later for calculating pseudoranges... (if I'm not wrong)
<kristianpaul>
hum. but how you track if the carrier nco is not fixed first?
<kristianpaul>
or i'm misiing something..
<kristianpaul>
agrh, i must leave now, but my irc client gets here catching
<kristianpaul>
bye Artyom
<Artyom>
bye
<kristianpaul>
but you read the accumulators right? i mean after initializr CODE_NCO and CARRIER_NCO ?
<kristianpaul>
also if read it must be before got overwrite
<Artyom>
I read only i_prompt,q_prompt,i_late,q_late
<kristianpaul>
i read all, but zero is the cotent tought..
<kristianpaul>
okay now leaving, i'm late ;)
<Artyom>
bye
<Artyom>
I must make a note: I tried to use my own code for tracking. In general we have only to read i_promt,q_prompt,i_late,q_late_i_early,_qearly in order to calculate errors of our carrier-generator and code_generator. And based on these 6 values we can calculate new values for CODE_NCO and CARRIER_NCO.
<Artyom>
In osgps there are some additions to the general rule:
<Artyom>
During pull-in process additionally navigation bits border is also identified. And additional checks are made in order to be sure that the process is working correctly.
<Artyom>
And also osgps uses only 4 values i_prompt, q_prompt, i_late, q_late.
<Artyom>
Based on these 4 values every ms during pull-in process new CARRIER_DCO and CODE_DCO values are calculated. During tracking process CARRIER_DCO is updated every ms and CODE_DCO is updated every 20 ms.
<Artyom>
And CODE_MEASUREMENTS/CARRIER_MEASUREMENTS are used only every 100 ms to calculate pseudoranges.
<rjeffries>
wolfspraul I was w-r-o-n-g re ARM costs. The use case I was thinking of is this part:
<rjeffries>
NXP LPC1768, ARM Cortex M3 100MHz, ~$5 in >1K volume.
<roh>
meh.. this shipping logistics makes my brain hurt
<roh>
these madmen who wrote those texts and regulations
<rjeffries>
semi-unrelated factoid: the per-piece royalty to ARM when a licesee produces an ARM-based CPU is as low as $00.07 per chip
<rjeffries>
hello roh
<roh>
rjeffries: yeah. thats not really a cost factor for us at the volumes we do.
<rjeffries>
roh I was not suggesting it was. I had calimed a 1GHz Arm was $5 I was wrong about that
<wolfspraul>
rjeffries: fair enough.
<wolfspraul>
even lower than 7 cents
<wolfspraul>
2-40 cents, afaik
<rjeffries>
it is a tough business for sure
<roh>
imx233 is 7.05Euro at digikey
<wolfspraul>
nah, all fine. they don't shoulder the expensive and risky part.
<roh>
454mhz
<roh>
gnnnh.
<roh>
wolfspraul: any idea what zolltarifnummer to use?
<wolfspraul>
no idea
<roh>
fsck.. i havent got a clue either.. there are thousands
<roh>
it seems i have to atleast fill a CN23
<roh>
fsck. need this number.. gah. 1h till the shop closes
<wolfspraul>
roh: is that the same as HS code? I found "390690Â Â Other Acrylic Polymers"
<wolfspraul>
:-)
<wolfspraul>
but there's also metal and other stuff inside...
<roh>
exactly.. i only found codes withing 39xxxxxx which are for uncut material
<roh>
this zoll-lists are a serious case of TL;DR
<wpwrak>
roh: try to google for something similar in china. they sometimes list the HS code.
<wpwrak>
roh: i.e., acrylic case screws "hs code"
<wpwrak>
first hit: Face plastic case with screws (HS Code : 85439000, made in china)
<wpwrak>
854390Â Â "Parts of Particle Accelerators, Audio Mixers, High Frequency Amplifiers" hehe ;-)
<roh>
maybe i should just note the first 4 chars and a ?
<roh>
3906?
<roh>
need to run. closing in 10 minutes
<wpwrak>
you can abbreviate the numbers. but i don't remember to what point.
<wpwrak>
ask them if they actually want the code :)
<wpwrak>
fedex usually do (but they're probably okay without it, too)
<wpwrak>
when i asked at the postal office, they said "no" (there's room on the form for it, in case you insist)
<wpwrak>
wolfspraul: how's the news coming along ? the 2 months schedule seems to be a little tough for the sheer quantity of things - even if july was actually fairly quiet on the ben side (and quite the contrary on the m1 side)