Pandora Batch 2: Will Wifi Be More Stable?


doublebeta

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Hey guys, i don't know if this is the right forum(hell, IRC might be a better place) but I was wondering if for Batch 2's boards the impedance issues on the wifi line will be fixed, which was causing problems and required a software fix. I see no reason why it shouldn't :ph34r: but I asked anyway :D. You might not be able to because making it bigger might make something else go weird because that's just what happens sometimes (life's a betch huh?), but I hope not :eek:.

It's also quite possible that it was right all along for most of batch 1 anyway, hmmm.....

Also, what speed is the Wifi chip capable of, in proper conditions?
And does anyone know the average latency of Bluetooth at about 3 meters? Think it would be suitable for gaming?
 
Bosbeetle said:
havent had problems with the wifi (yet)
Yes, the problem was mainly speed after the software fix(IIRC), tho i believe it does drop a lot of wifi packets(or something else, frames mebe), which would cause problems on a D-Link router like mine, it shts a brick after a few dropped frames..
I did hear about the piggyback resistor 'fix', but I was pretty sure it was a temporary fix. And with the speed a reviewer said, which is fine for web browsing, isn't really great if you were streaming. i've forgotten the speed he said tho, and where the post is located. Maybe he just got an 'unlucky' pandora.
EDIT: Here's what was in the dev blog:

1. The WiFi issue - finally resolved

A lot of guys have probably already followed this on the boards: notaz was working on the WiFi driver and still couldn't get it to work reliable. As he didn't know what else to try, he thought it could also be a hardware issue - of course, that got us alarmed. Michael immediately stopped the board production (700 had been produced so far back then) to first do more tests with WiFi. We were totally in the dark. If you ever wanted to know how sudden death feels... well, we do know for sure yet.

Michael did begin investigating the hardware while notaz did more tests and tweaks with the software. A kernel which disabled everything except WiFi did get a bit more speed out of the WiFi, but it still was very slow. Was it the driver causing problems when other stuff was running? Or was it the hardware? We still didn't know for sure.

As we didn't know, we decided we will get some WiFi sticks for the beginning and ask every customer whether he wanted to get the Pandora with a stick and internal WiFi that might be fixable by software or maybe needs a hardware fix later.

Then, at one time, we found out that WiFi was faster on Rev2/3 boards then on the recent Rev4/5 boards - pretty weird, as nothing had been changed in these revisions that could affect WiFi. Except the board manufacturer. Using that clue, we figured out that the impedance of one trace had been changed. The impedance is important here, as a wrong impedance will distort the signal and then the module doesn't get a clean clock. Measuring the clock signal did prove that: Yep, the impedance had been changed.
Who's fault was it? Hard to tell. The company had changed that trace without asking, but we also didn't explicitely say it needs to have a correct back. So it's a hard thing, the trace is working, it was just not good enough for the signal.
Knowing that, Michael did work on it for a couple of days, doing some trial and error (not much you can't do unless you do know the exact new impedance).
He got it working better - but still not good enough to really be usable - was this due to software? Or still hardware?
So he started to work on a new testing board (Rev6) which could also be used as new board for the rest of the 3300 Pandoras if it fixes WiFi.
While doing that, he had another idea - modded another Rev5 board and got a HUGE speed increase! On minimal kernel, he can get 350KB/s, on normal image he gets 66KB/s stable speed (tested downloading from the internet. That fix is easy: Simply piggyback a resistor on top of an existing one. Takes about 1 - 2 minutes. And the rest of the 3300 boards can be populated with the new resistor immediately, so that fix won'tl be needed on them.
Speed can probably still be improved - Michael just found out about that yesterday, he will try to tweak more (or even combine the two mods) during the next days, until he leaves for UK to start assembling (he will do the modification of each board while assembling).
Finally! That news did make us more alive again, we were really suffering during the last days...

So while it works, and 66kB in't bad for web browsing, the possible 350kB/s(which can likely go higher) speed that is possible in the minimal kernel can go higher on the full kernel. Three cheers for Michael's quick work back there tho :D.
 
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I've no problems with WiFi either: goes as fast as my desktop PC, and haven't had any problems with lost connections or anything.

The signal strength also seems to be pretty good: the other day I was in the street outside my house(3rd floor BTW) and was browsing the Nets no problem. It was a real Pandora moment actually, where you think "Is this cool or what?" :)
 
oh in batch 2 it is going to be really stable... you can put about 2 elephants on it.
 
AFAIK every shipped Pandora so far has received MWeston's manual resistor fix. The next batch of boards from Texas should have this already fixed in the design. It will be interesting to see if there's any difference.
 
There might be an issue with batch 2, but it is the combination of the track and the resistor which is important. For Batch1, that is now fixed so there is no major improvement to make in the hardware. I think we still expect improvements in software, mainly to do with Network Manager having bugs.
 
I have no problem with wifi.
I don't get any deconnection while i'm home.
scp report 600kB-800KB on average which isn't bad either :)
 
My wifi is slow and gets disconnected randomly.

But the reception sucks where I am, all my other devices also get bad reception but at the same time they don't drop the connection.

Also, when i'm out and about walking around with the pandora, I pick up sooo many more wifi connections than my laptop. I guess it's a tradeoff.
 
Mofokubik said:
My wifi is slow and gets disconnected randomly.

But the reception sucks where I am, all my other devices also get bad reception but at the same time they don't drop the connection.

Also, when i'm out and about walking around with the pandora, I pick up sooo many more wifi connections than my laptop. I guess it's a tradeoff.

yes, my WiFi reception seems better on the pandora than any other device. Dropping of the connection is actually a problem of not re-connecting, I think - and might 'just' be software.
 
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sebt3 said:
I have no problem with wifi.
I don't get any deconnection while i'm home.
scp report 600kB-800KB on average which isn't bad either :)

Where did you get these speeds from?
Mine peaks at 150 kb/s
 
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Mine peaks at about 450 consistently. No issues at all
 
then I would REALLY know what causes the difference.
Even directly next to my router it gets max. 150 kb/s with wget. And website loading is slow.
 
sebt3 said:
I have no problem with wifi.
I don't get any deconnection while i'm home.
scp report 600kB-800KB on average which isn't bad either :)

both my units only went to around 100kbs and usualy only had a speed of 55/62kbs on transfers ,most other people with pandora's have said the very same thing ,can you go and download some files and let us know for sure what speed you are getting ,and about all these true tests of wifi speed ,theres nothing like actuly downloading from a fast server in real time to see what you really are getting ,also try downloading the same file a few times.


i was getting 60 - 110 -and sometimes 210kbs but it wouldn't stay at sny of those speeds,wifi is really messed up ,hope its a driver only problem and that the driver gets fixed soon.
 
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Gruso said:
AFAIK every shipped Pandora so far has received MWeston's manual resistor fix. The next batch of boards from Texas should have this already fixed in the design. It will be interesting to see if there's any difference.

No, only the first box needed to be fixed, all the others shipped since have not needed to be modded, ie the boards were populated correctly.
 
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Mine usually peaks at 800~ kbyte/s, though it then slows down, alot... normal dl speeds is around 100 kbyte/s, most consistent speed i've had is 600kbyte/s throught the whole download.
 
doublebeta said:
Bosbeetle said:
havent had problems with the wifi (yet)
Yes, the problem was mainly speed after the software fix(IIRC), tho i believe it does drop a lot of wifi packets(or something else, frames mebe), which would cause problems on a D-Link router like mine, it shts a brick after a few dropped frames..
I did hear about the piggyback resistor 'fix', but I was pretty sure it was a temporary fix. And with the speed a reviewer said, which is fine for web browsing, isn't really great if you were streaming. i've forgotten the speed he said tho, and where the post is located. Maybe he just got an 'unlucky' pandora.
There was no software fix, it was entirely hardware. the piggybacked resistor was only applied to the first 800 (or so) that had already been populated. All remaining ones get the correct resistor to match the impedance put onto them from the start. It was the incorrect resistor value that was causing the dropped packets and subsequent slowdowns.
Most users seem to be getting a pretty stable 500-900KB. The chip itself may only be capable of reaching about 900KB/s: it is the same as in the N900 (I think. One of the Nokias at least. If it matters I'll look up to be absolutely certain) which has a reported max speed of 900KB/s
900KB/s is well more than enough to stream HD video in real time. Even half of that should be able to handle all but the highest bit rates.
There do seem to be a few users stuck at about 50-150KB/s for some reason, however. I haven't got a Pandora, but limited testing that I've been able to ask those with them to do suggests that it isn't a hardware fault: there's no dropped packets or anything, it is just slow. This could be a software thing, or it may be a result of some incompatibility with the router.
 
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