Re: Bug #1024 (oscillating re-camping), the latest news.
Hello Leonti, Leonti Bielski wrote: > Did you measure the capacitor on other "normal" phones? > If on the phones without the problem capacitor measures around 10uF as > supposed than we have our solution :) I did not measure them yet (its some effort to remove the capacitor without breaking anything and I don't have a huge pile of phones for experiments). But even if the capacity of "good" phones is know, this does not mean a lot. Till now its not 100% clear what effect the larger capacitor has. It could be that it reduces voltage drops if the Calypso chip wakes up. But it could also be that it reduces noise which comes from the rest of the system. I can imagine that there are a lot of parameters which determine how noise from the outside of the GSM modem can disturb the affected supply voltage of the Calypso and most certainly there are differences between the phones . I don't have the hardware equipment to make detailed enough measurements to find out which of the above is true (if not something else or a mixture of several different things). And finally we don't have the documentation of the details inside the Calypso. So we can only speculate what can cause the problems. We know that there is a PLL inside the Calypso and that this PLL seems to be rather sensible, but we don't know what exactly happens when the Calypso is sent into "Deep Sleep" and when it wakes up again. During those transitions there is a switch from the main clock to the 32 kHz clock, but again, we don't have the details. Best regards, Dieter ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
Re: Bug #1024 (oscillating re-camping), the latest news.
Did you measure the capacitor on other "normal" phones? If on the phones without the problem capacitor measures around 10uF as supposed than we have our solution :) Leonti On Wed, May 6, 2009 at 5:48 PM, Dieter Spaar wrote: > Hello, > > I spent quite a lot of time to modify and patch > various settings in the GSM firmware trying to change > the behavior of the two phones which show the extreme > "Deep Sleep" problems (immediate PCH reception error > if the phone enters "Deep Sleep"). > > Those modifications did not remove the problems and > also did not cause any problems for the working > phones I have. So till now it seems that there is > no software workaround which can solve this problem. > > However on one phone I was able to solve the problem > by replacing a capacitor which buffers one of the > power supply lines of the Calypso chip (the power > comes from an LDO in one of the other GSM chips). > This capacitor is supposed to be 10uF, however > I measured 7.6uF. I don't have SMD parts here so > I replaced it with a standard 10uF electrolytic > capacitor (I measured 10uF). After this > modification the "Deep Sleep" problems are gone > and the phone works as good as the other good ones. > > Its still too early to conclude anything from > the above. I have ordered a few SMD capacitors > and will try the same with the other problematic > phone. Additionally its necessary to test if this > modification just moves the problem to lower > temperatures (remember, the problems also go > away if I warm up the phones by a few degree). > > Best regards, > Dieter > > > ___ > hardware mailing list > hardware@lists.openmoko.org > http://lists.openmoko.org/mailman/listinfo/hardware > ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
Re: Bug #1024 (oscillating re-camping), the latest news.
Hello, I spent quite a lot of time to modify and patch various settings in the GSM firmware trying to change the behavior of the two phones which show the extreme "Deep Sleep" problems (immediate PCH reception error if the phone enters "Deep Sleep"). Those modifications did not remove the problems and also did not cause any problems for the working phones I have. So till now it seems that there is no software workaround which can solve this problem. However on one phone I was able to solve the problem by replacing a capacitor which buffers one of the power supply lines of the Calypso chip (the power comes from an LDO in one of the other GSM chips). This capacitor is supposed to be 10uF, however I measured 7.6uF. I don't have SMD parts here so I replaced it with a standard 10uF electrolytic capacitor (I measured 10uF). After this modification the "Deep Sleep" problems are gone and the phone works as good as the other good ones. Its still too early to conclude anything from the above. I have ordered a few SMD capacitors and will try the same with the other problematic phone. Additionally its necessary to test if this modification just moves the problem to lower temperatures (remember, the problems also go away if I warm up the phones by a few degree). Best regards, Dieter ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
Re: Bug #1024 (oscillating re-camping), the latest news.
Am So 3. Mai 2009 schrieb Dieter Spaar: > Instead of messing around with all of this and making things more > complicated, I thing the current solution to detect re-camping and > enable AT%SLEEP=2 is the better approach (maybe adjust the > algorithm slightly). Regarding all the arguments I deleted in above quote - I'm quite aware of these and mostly agree. Anyway, the current algorithm relies on detecting actual recamping, and this inevitably creates a certain offline time during the first recamping events. OTOH warming of battery as well as warming of TX-chip might not be a adequate criterion for switching to sleep4, anyway both sensors reporting "cold" might create an additional criterion for switching to sleep2 though and thus possibly avoiding any recamping at all. cheers jOERG signature.asc Description: This is a digitally signed message part. ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
Re: Bug #1024 (oscillating re-camping), the latest news.
Hello, Timo Juhani Lindfors wrote: > Joerg Reisenweber writes: > >> Suggestion to FSO to improve sleep=2 workaround: Use temp reading (e.g. from >> battery, or even from calypso if we put that to operation) to switch between >> sleep=2 and sleep=4 >> > > Does calypso have a temperature sensor? That'd be very cool. The > battery temperature sensor can not be reliably used to measure outside > temperature since the battery heats itself a lot. > There is a temperature sensor in the GSM transceiver chip. However I don't think that this sensor is supposed to measure the temperature of the environment, most certainly the purpose is to adjust some RF parameters depending on the transceiver temperature (e.g. RF power). And don't forget that the GSM modem is shielded, this probably cause the temperature inside the modem to be different or follow the outside temperature only slowly. Additionally this sensor is not enabled in the GSM firmware, it always reports 0. We don't know why it is disabled, but lets assume its intentional. If we enable the sensor, we might break something else because suddenly the temperature is no longer 0. We don't know where and if the temperature value is used inside the GSM firmware because we don't have the source code for the relevant parts. The sensor is queried by a regular task of the GSM firmware so I also don't think its a good a idea to query the sensor on our own and might get in conflict with this task. It might be possible to make the raw value of the sensor available somehow. Besides the required effort I don't think this would help a lot for bug #1024. Till now it looks like only the Calypso chip itself is the part which is responsible for the temperature related effect of bug #1024. If the GSM modem is sending, I expect the transceiver chip to get warmer than the other chips so the sensor value would not necessary reflect the temperature which affects bug #1024. And of course so far it seems that there is no exact temperature when bug #1024 begins to show up, the phones behave different. Instead of messing around with all of this and making things more complicated, I thing the current solution to detect re-camping and enable AT%SLEEP=2 is the better approach (maybe adjust the algorithm slightly). Best regards, Dieter ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
Re: Bug #1024 (oscillating re-camping), the latest news.
Joerg Reisenweber writes: > Suggestion to FSO to improve sleep=2 workaround: Use temp reading (e.g. from > battery, or even from calypso if we put that to operation) to switch between > sleep=2 and sleep=4 Does calypso have a temperature sensor? That'd be very cool. The battery temperature sensor can not be reliably used to measure outside temperature since the battery heats itself a lot. ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
Re: Bug #1024 (oscillating re-camping), the latest news.
Am So 3. Mai 2009 schrieb Dieter Spaar: > Hello, > > Dieter Spaar wrote: > > Its still too early to conclude anything from this > > observation, its just one GTA02. I am waiting for > > the second GTA02 to find out if it behaves the same. > > > > A short update: > > The second phone arrived, it shows the same extreme > re-camping as the first phone (PCH reception error > immediately after going into "Deep Sleep"). And if > the phone is warmed up by a few degrees, the > problem goes away, when it cools down, PCH > reception errors in "Deep Sleep" show up randomly > until they are back all the time. > Suggestion to FSO to improve sleep=2 workaround: Use temp reading (e.g. from battery, or even from calypso if we put that to operation) to switch between sleep=2 and sleep=4 cheers jOERG signature.asc Description: This is a digitally signed message part. ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
Re: Bug #1024 (oscillating re-camping), the latest news.
Hello, Dieter Spaar wrote: > Its still too early to conclude anything from this > observation, its just one GTA02. I am waiting for > the second GTA02 to find out if it behaves the same. > A short update: The second phone arrived, it shows the same extreme re-camping as the first phone (PCH reception error immediately after going into "Deep Sleep"). And if the phone is warmed up by a few degrees, the problem goes away, when it cools down, PCH reception errors in "Deep Sleep" show up randomly until they are back all the time. Best regards, Dieter ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
Re: Bug #1024 (oscillating re-camping), the latest news.
Am Do 30. April 2009 schrieb Michael 'Mickey' Lauer: > Thanks for the update, Dieter. > > That might explain why I'm suffering so bad from this bug, since my office is > located in the souterrain and it's usually pretty cold here. > > :M: Another fridge-bug after WSOD :-/ strange, usually it's the other way round for electronics. I also noticed #1024 only when in "biergarten" and it's been rather low temp, but never at home where I like it comfortable. /j signature.asc Description: This is a digitally signed message part. ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
Re: Bug #1024 (oscillating re-camping), the latest news.
Thanks for the update, Dieter. That might explain why I'm suffering so bad from this bug, since my office is located in the souterrain and it's usually pretty cold here. :M: ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
Re: Bug #1024 (oscillating re-camping), the latest news.
Am Mi 29. April 2009 schrieb Werner Almesberger: > Dieter Spaar wrote: > > Finally, after a while I found out that the problem goes > > away if I warm up the Calypso chip by a few degrees. re-reflow the chip? Or maybe consult your dentist? ;D /j signature.asc Description: This is a digitally signed message part. ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
Re: Bug #1024 (oscillating re-camping), the latest news.
Dieter Spaar wrote: > Finally, after a while I found out that the problem goes > away if I warm up the Calypso chip by a few degrees. So the phones are actually future-proof. With Global Warming, the Calypso will encounter agreeable conditions most of the time within just a few years ;-) > So this is it for today, just to let you know that > bug #1024 is not forgotten ;-) Thanks a lot ! This bug is really a vicious beast :-( - Werner ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
Bug #1024 (oscillating re-camping), the latest news.
Hello, here is the latest news about the investigation of bug #1024 (oscillating re-camping). I finally received a GTA02 which exposes the behavior of bug #1024 and a second one is on the way (Thanks again to those who send me the phones, you know who you are). This one GTA02 which I am already playing with for some time shows re-camping in a very extreme form, if the phone goes into "Deep Sleep" while receiving the PCH, the next reception will fail immediately. It does not care how long this "Deep Sleep" period is, the next PCH reception will simply fail. My other GTA02 phones work perfectly in the same situation (a simulated test cell) and show no problems at all with "Deep Sleep". To find out if the 32 kHz oscillator is responsible for the problem, I connected an external, stable and accurate clock signal: No difference, still the extreme behavior in "Deep Sleep". Finally, after a while I found out that the problem goes away if I warm up the Calypso chip by a few degrees. The other chips of the GSM chipset (Digital Baseband and RF Transceiver) or the 32 kHz and 26 MHz oscillator don't care about warming, only if I warm up the Calypso, the problem goes away and this GTA02 behaves as good in "Deep Sleep" as my other GTA02 do. Additionally if the Calypso cools down again, it slowly begins to expose problems in "Deep Sleep" every now and then until finally the extreme behavior (PCH reception failure immediately after "Deep Sleep") is back again. Its still too early to conclude anything from this observation, its just one GTA02. I am waiting for the second GTA02 to find out if it behaves the same. I am also trying to find out if there is a way to remove this "Deep Sleep" problem with a modification of the GSM firmware. The transition into "Deep Sleep" and back again is a rather complex process, there are all three GSM chips involved, so there is a chance that things go wrong here at some point. However the big problem is (again and as usual) that we don't have the Source Code of this part of the firmware. So its rather time consuming to find and understand the responsible parts of firmware, patch them and test the result. So this is it for today, just to let you know that bug #1024 is not forgotten ;-) Best regards, Dieter ___ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware
