Re: no-cap bass fix
On Wednesday 24 March 2010 16:22:15 Joerg Reisenweber wrote: This is *STRONGLY DISCOURAGED* and will break quite a couple of things. Details see inline below [Stefano Cavallari Di 23. März 2010]: Yesterday night I was going to fix the poor audio response of the Freerunner. Just before starting to solder (having opened the phone and the metallic plate) I discovered the caps I got were the wrong ones. So I looked at the scheme for an alternative solution, and I decided to try to replace the audio caps with 0R, thus losing DC blocking. You're not only losing the DC-decoupling, you're also losing the negative half of the sine wave, when amp is basically shorting output to GND to create the negative current by discharging the coupling capacitor. See operation principles of analog bridge amp outputs in some good book about electronics. This is NOT a class-A amp (http://en.wikipedia.org/wiki/Electronic_amplifier#Class_A ), means it never opens both the pullup and pulldown transistor concurrently. The LM4853 is a class-B push-pull bridge. I should have read the data sheet. Audio does not seem distorted though, except at high gains. There is a some white noise in the background, not noticeable when music is running though. Anyway I was ready to use external capacitors in the adapter cable. The plan was to measure the DC component and if low enough, leave it as it. If not, putting the DC filter in the minijack adapter. This is basically feasible, but will most surely break JACK_INSERT logic, by applying a voltage 0V to the GPIO detecting if a jack is inserted or not. Each time you enable the amp to output some sound the headphones, it will latch up and not detect jack removal. And it's quite unlikely jack insertion is correctly detected each time as well, there also might be both false positives and false negatives. Jack sensing still works and seems reliable. Anyway if it stop working or it proves to be not reliable I can just disable it. I'll never use an headset, just headphones for playing music. I can force the output to the jack when starting the player. So I did that, and it seem to work. I tried first with a multimeter. It reads 0.2 V DC, but I have to confirm it with an oscilloscope. This reading probably is with headset amp disabled. Correct reading should be Vmid, i.e. ~1.6V I tried the audio with very cheap headphones first (I was afraid of burning them), Chances are you actually will end up with broken headset speakers, just because of this then with decent ones. It seems to work way better! Now I just need a better adapter cable (mine need to be inserted middle way, it's not the right one), and then I have usable audio :) Don't you think, if this was a viable workaround for the problem, we at OM (particularly me in this case) came up with this suggestion some 1.5 .. 2 years ago? It depends on what you mean for viable. It is not something correct, and I was aware of that. Building a custom cable with non-SMD capacitors is easier than finding right capacitors. Risking some cheap headphones that will sound way better than good headphones on a unfixed phone is even easier. I just wanted to share my experience, maybe someone finds this compromise useful. -- () ascii ribbon campaign - against html e-mail /\ www.asciiribbon.org - against proprietary attachments signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
no-cap bass fix
Yesterday night I was going to fix the poor audio response of the Freerunner. Just before starting to solder (having opened the phone and the metallic plate) I discovered the caps I got were the wrong ones. So I looked at the scheme for an alternative solution, and I decided to try to replace the audio caps with 0R, thus losing DC blocking. The plan was to measure the DC component and if low enough, leave it as it. If not, putting the DC filter in the minijack adapter. So I did that, and it seem to work. I tried first with a multimeter. It reads 0.2 V DC, but I have to confirm it with an oscilloscope. I tried the audio with very cheap headphones first (I was afraid of burning them), then with decent ones. It seems to work way better! Now I just need a better adapter cable (mine need to be inserted middle way, it's not the right one), and then I have usable audio :) -- () ascii ribbon campaign - against html e-mail /\ www.asciiribbon.org - against proprietary attachments signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: OT: Where can I meet a female companion with similar interests and personality /in person/?
What about opening a free blog and write your thoughts/happenings there? You can post the URL here ONCE, so whoever is following you and/or willing to help will be able to continue. There is a reason there isn't a single global mailing list for everything. I hope you understand this. Don't ever bother to reply, I just tweaked a filter rule to ignore your posts more accurately. -- () ascii ribbon campaign - against html e-mail /\ www.asciiribbon.org - against proprietary attachments signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
digital audio paths (Was: Re: Experimental technique for testing call audio quality? )
On Friday 22 January 2010 20:13:58 Timo Juhani Lindfors wrote: Helge Hafting helge.haft...@hist.no writes: the same quality as this, by tweaking volume settings. Calls are digital The audio data is fed to the GSM chip in analog form however. If the FR sound quality is too bad, consider a BT headset. Sound quality should then depend on the BT headset only. The FR's problems with buzz, bad bass, and possibly other analog issues shouldn't matter at all. Even in this case the audio is fed in analog form to the GSM chip. Why on hell GSM chips are still done this way? I hope whatever next open phone comes around it's totally digital. Audio lines maybe were a good idea for phones with few cpu power available, but now it's only a waste of PCB space I think. The hardware becomes more flexible and maybe you can do some DSP to enhance the voice. Or implement an answering machine inside the phone. Do anyone know about recent GSM chips? I'm still dreaming a up-to-date open phone :) Is there a standard to do voice-audio-codec over multiplexed AT channel? -- () ascii ribbon campaign - against html e-mail /\ www.asciiribbon.org - against proprietary attachments signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: IDA Systems Freerunner sales update
On Wednesday 13 August 2008 15:46:44 Flyin_bbb8 wrote: Yes but having a creditcard payment method is preferable than wire transfers, as you'll have to go to your bank, fill a form.. da da da... Decent banks have an online e-banking site. Wire transfers are generally cheaper too. Don't know in Asia but here in Europe is so. -- signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Yummy new CPU/GPU combo
X certainly can do that, but AFAIK without specs you can't do hardware scaling, so using anything different than the screen resolution would be slow and/or use too much cpu thus drain the battery. On Friday 06 June 2008 09:08:41 David Samblas Martinez wrote: Carsten, There is any posibility to change the screen resolution without reboot? If we can do so we can dinamically change it to got the best of two worlds, a high resolution for almost statical screens to webbrowsing, doc editing, picture viewing, an a low resolution to mame, video playback(?), and anything else doesn't fit on high res. It can be done? Regards -- signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: 2.5mm or 3.5mm
I'm for B, as I'd like to use a phone as a music player. Most people use a bluetooth headset, and anyway there are some 3.5 headsets if one don't like bt ones. 3.5 connectors are easier to solder, too. Thank you for asking, you demonstrate you really care about what customers *actually* want! On Friday 30 May 2008 08:18:16 Joerg Reisenweber wrote: Hi community! A short poll: on a future GTA0x (2), would you prefer to have A) standard 2.5mm headset (mic+phones) connector, where you have to buy a cheap adapter if you want to use your old headphones, (the way like it's for GTA01/02) or B) classic 3.5mm headphones Walkman(R) connector, where you have to DIY an adapter for any standard cellphone headset? (or does anybody know of 3.5mm headSET standards or adapters?) please hurry to vote, we have to make a decision. Thanks cheers jOERG Openmoko-HW-development -- signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Do we REALLY need a phone?
On Monday 21 April 2008 08:54:15 Shawn Rutledge wrote: On Sun, Apr 20, 2008 at 3:10 AM, Stefano Cavallari [EMAIL PROTECTED] wrote: Then you just provide some module to access the chosen network, like a SDIO card (probably with a big external part like most wifi ones). I was thinking of a beast like a bluetooth UMTS dongle. There are already USB I used to think like that too. Maybe it's a good idea. It would certainly be way better for the environment. However, it costs more in several ways (engineering, components and space) to make it modular, and for the idea to make sense you are relying on a couple of things: that the handheld will satisfy you for such a long time (10 years maybe), and that it will make sense to continue to build modules with whatever interface you chose at the beginning (considering that the minimum-sized module you can build at the beginning will be looking excessively big in a few years). I wasn't going that far in building the device 100% modular despite it would be cool. I was talking about just the UMTS/GSM part as it uses different frequencies in different regions, and it's not deployed everywhere. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community -- signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Do we REALLY need a phone?
(sorry for the length of this message) I was thinking today about how the phone system is quite dead without no one noticing it. We are paying unreasonable tariffs for just sending data which happens to be voice. The whole motivation behind having a number is no longer existent as with portability and roaming you don't do switching anymore. So you don't want to access the telephone network, you want to access the Internet, then do whatever you want from there. Yes in the meantime you may still want to do normal calls but the focus is in doing VoIP and IM. Because of this I think the next moko should be designed around this and be mainly a handheld. With no included GSM module so you can focus in the interesting part of the product and don't bet on the next mainstream communication technology (mobile wimax? UMTS? EDGE? CDMA something?) and just provide the one you are sure they will be supported for much time (wifi, bluetooth). Then you just provide some module to access the chosen network, like a SDIO card (probably with a big external part like most wifi ones). I was thinking of a beast like a bluetooth UMTS dongle. There are already USB UMTS dongle right now which emulates a serial port. So it's a no brainer to take an existing design, strip the usb-serial chip and put a bluetooth-serial chip and a battery (the usual nokia one which most GPS and the Neo uses). This gives the advantage of not having a powerful antenna attached to the ear (when talking) or anyway near you (when messaging, browsing). You can put it near a window and get better signal, and so on. Of course some may find the SDIO more appealing or not. Anyway if you keep this component separated you let the user choose whether they really need GSM, you can develop the hardware WAY faster and most important, you don't have to wait for the comm. modules to be functional to start selling, and if a comm. module happens to be a total market/design/whatever failure you still have the main product (the handheld) selling well. Just my (long) 2 ¢ -- signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Do we REALLY need a phone?
On Sunday 20 April 2008 13:49:29 Schmidt AndrXs wrote: I disagree with that GSM phone is dying. In Europe almost everyone over 12 has a GSM phone and use it every day. How can you state it is dying? I said it is dying but few realizes it yet. Sooner or later people will want a internet connection with them. And the step from that and no longer needing a the full fledged phone network is quite small. On the other hand noone knows what would happen to the Internet if all those people would choose to use VOIP instead of PSTN (Public switched telephone network). You can potentially use less bandwidth if you choose more intelligent codecs. And yes I'm for paying actual bandwidth for mobile Internet. The Internet doesn't mean necessarily broadband and flat prices. And remember that IM is way more efficient (both from the human and the hw point of view) and cheap than VoIP, so many people would just switch to IM. It's because of absurd SMS costs and size limits that few uses them. The two networks have completely different characteristics and PSTN is better for voice communication. With GSM you are already using a digital protocol with a very lossy codec, and the latency is quite high (about 400 ms last time I checked). VoIP let's you choose the codec quality and associated costs. A better provider gives you lower latencies and jitter. People will just switch to the best one. So VoIP is potentially way better than PSTN :) ramsesoriginal wrote: On Sun, Apr 20, 2008 at 12:10 PM, Stefano Cavallari [EMAIL PROTECTED] wrote: (sorry for the length of this message) I was thinking today about how the phone system is quite dead without no one noticing it. We are paying unreasonable tariffs for just sending data which happens to be voice. The whole motivation behind having a number is no longer existent as with portability and roaming you don't do switching anymore. So you don't want to access the telephone network, you want to access the Internet, then do whatever you want from there. Yes in the meantime you may still want to do normal calls but the focus is in doing VoIP and IM. Because of this I think the next moko should be designed around this and be mainly a handheld. With no included GSM module so you can focus in the interesting part of the product and don't bet on the next mainstream communication technology (mobile wimax? UMTS? EDGE? CDMA something?) and just provide the one you are sure they will be supported for much time (wifi, bluetooth). Then you just provide some module to access the chosen network, like a SDIO card (probably with a big external part like most wifi ones). I was thinking of a beast like a bluetooth UMTS dongle. There are already USB UMTS dongle right now which emulates a serial port. So it's a no brainer to take an existing design, strip the usb-serial chip and put a bluetooth-serial chip and a battery (the usual nokia one which most GPS and the Neo uses). This gives the advantage of not having a powerful antenna attached to the ear (when talking) or anyway near you (when messaging, browsing). You can put it near a window and get better signal, and so on. Of course some may find the SDIO more appealing or not. Anyway if you keep this component separated you let the user choose whether they really need GSM, you can develop the hardware WAY faster and most important, you don't have to wait for the comm. modules to be functional to start selling, and if a comm. module happens to be a total market/design/whatever failure you still have the main product (the handheld) selling well. Just my (long) 2 ¢ -- I have always been a big fan of the maximum modularity and abstraction, and I totally agree on this part of your idea. I also agree that the telephone system is a dying system, but since all of your friends/family use it, and since we stil have no real mobile alternative, i think its a bit to early for throwing away the whole gsm parts. And that's why I like modularity: like you said, every one can choose wether to have gsm, wifi, wimax, umts, or a some sort of star trek transponder. But since this would be a complete redesign of the system, and a reinvention of the concept of mobile handheld. The idea is really innovative, but difficult. Sure nothing to produce after the gta3, but maybe to start developing.Ideally the modularity could be extendend to some sort of wireless, maybe bluetooth. btw, we already discussed a modular design some time ago... but I don't remember how we decided. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community -- signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org
Re: Do we REALLY need a phone?
On Sunday 20 April 2008 15:14:58 ramsesoriginal wrote: [...] I also would say that I don't know about Stefano, but i thought of this as a modular system when I read this mail: If you feel the need for gsm you put in the gsm module, if you think oyu need 4g you put in that chip, and if you think you need something else, then simply use something else. Doing this way you, for know, you simply creatre the gsm module. Then you create some 4g module, and people can buy it, upgrade their phone, put it in a new barebone system, or whatever they want. Having a modular approach gives true freedome, in my opinion Yes that's exactly what I was talking about. In fact it is independent of the phone system is dying argument as most advantages applies for legacy phone system use. It's just that I thought this because of the other reasoning :) -- signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Data over normal GSM call
On Monday 14 April 2008 21:00:34 Harald Welte wrote: On Sun, Apr 13, 2008 at 07:57:02PM -0500, Hans L wrote: [...] AFAIR, the DTMF key press is encoded and send over the Um (air) interface to the BTS/BSC/MSC and then in the end converted into actual audible sounds. Please see Page 22 of http://www.chu.edu.tw/~lhyen/wc/gsm.pdf for a graphical illustration how this works. This imply that there is a data channel available. Can you trasmit anything else that DTMF? What is the bandwidth of this channel? -- signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: France : Taxes for video and mp3 playing capacity
On Friday 25 January 2008 01:00:06 Fabian Olesen wrote: this will not work in denmark, because the phone will be deemed capable of doing it. Why? The phone itself isn't capable to play anything until you add the software. It has a stereo audio circuitry, but it could be used just to listen and record calls and VoIP. I'd like FIC to sell mp3 software including in the cost the license to play mp3, along adding a notice (for the countries which need it) that the phone isn't licensed to play music and that if needed the support must be bought later. I remember Apple selling support for 802.11n for some of their MacBooks (which is *just* software). So you can say that hardware isn't capable of something until you add the software IMHO. On Jan 25, 2008 12:51 AM, Tim Erwin [EMAIL PROTECTED] wrote: France is about to taxe smartphone which provide 3 features : - At least 128mo internal memory (neo will have 256) - at least one touch/key dedicated to audio playing (what about a touchscreen ?) - mp3 or video playing Can this be worked around by not shipping the neo with mp3 or video software and make it up to the user to download this later? What about ogg or flac... ;) Cheers, Tim ___ OpenMoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community -- ___ OpenMoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: France : Taxes for video and mp3 playing capacity
On Friday 25 January 2008 16:00:58 Colan Schwartz wrote: I definitely don't think FIC (or now Openmoko) should include the cost (if there is one) of the licence to play MP3s. I don't want to pay that, and I don't think anyone else should either. I'm happy with just Ogg and FLAC files. Maybe an MP3 library can be downloaded separately, like the way most Linux distributions handle DVD playing. I mean a separate license with software, which you can choose to buy or not :) If you want to pay for MP3s, don't make me pay for it as well! ;) And I really like that speeding ticket analogy. This tax that assumes guilt is insane. I don't understand how modern democratic justice systems can tolerate it. -c. I think it is wrong too, and that is just a workaround to not classify the FreeRunner as a mp3 player device. -- ___ OpenMoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: France : Taxes for video and mp3 playing capacity
On Friday 25 January 2008 16:14:17 Stefano Cavallari wrote: On Friday 25 January 2008 16:00:58 Colan Schwartz wrote: I definitely don't think FIC (or now Openmoko) should include the cost (if there is one) of the licence to play MP3s. I don't want to pay that, and I don't think anyone else should either. I'm happy with just Ogg and FLAC files. Maybe an MP3 library can be downloaded separately, like the way most Linux distributions handle DVD playing. I mean a separate license with software, which you can choose to buy or not :) If you want to pay for MP3s, don't make me pay for it as well! ;) Do the law talk really about mp3 playing or about music playing? I think the latter is true. (can anyone confirm?) In that case you would need to pay the tax as long you provide an application which plays movies or music, whatever the format. -- ___ OpenMoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
