Build Your Own Linux Powered Pda Options

[koen]

Actually, if given a choice, I would go for a PXA255 or maybe 270 and a ATI accelerator video chip. If the drivers can be setup properly, the acceleration can overshadow a faster cpu in performance.

And in any case, performance in most scenarios that we use our Zaurus for requires processing of multimedia. I really don't hear much folks doing intensive mathematics on their Z ...

Both multimedia and math use floatingpoints a lot, so the i.mx31 would kick xscale ass in that department with its vfp unit (as would an omap3)

[Da_Blitz]

I am happy to do an xscale board but not at $120 per cpu, plus i prefer the intel 2700G as its a much more capable chip and easier to interface to as well as bieng well documented with publicly avalible infomation

but i have a feeling that this chip is in a class in terms of performance, the inbuilt vide (dual head), Open GL support (not the cut/enhanced down ES), MPEG4 encoding and decoding acceleration with post and pre filtering (such as deringing which is very cpu intensive) and floating point all coupled with a high performance bus (the xscales performance is rapidly reduced on IO and mem tasks) and ddr 266

so basically this 1 chip multimedia wise should blow the 2 chip soulution out of the water in terms of cost and performance, BUT i dont have any numbers to support that, i am going on the technical details i am reading in the referenc manual of both, beta player benchmarks, technical analisys of the xscales performance for difrent tasks and gut feeling.

i dont want to sound stuck up but those are what ihave bassed my desicion on, the price and avalibility being huge points.

speculatrix: for the audio stuff it has been discussed already and we came to the same conclusion to use a breakout box, i might be able to route spdif out oh one of the headphone jacks but only if i can place the spidf in a high impedence state (effctivly turning it off), were you asking for spdif in or out or both or both at the same time because if we have 2 headphone jacks we could have one for in and the other for out

both jacks will be 4 ring and will be left, right, microphone input/3rd sound output, gnd as there is only 2 adc's on the chip, i might change it to allow you to have it setup up as 3 outputs or 2 outputs and 1 input where the input can be taken from any ring bar gnd

those pics are nice but the way i look at it that would be a medium density desin (the mother board that is), i mention that because there are alot of people who dont think we have alot of space, if you have seen a HTC phone design then you will knom the density i am talking about

back to the main topic, bluetooth i think would be best on the full speed usb port as that port is effectivly useless in my mind (not enough speed for 802.11g) so connection of that is easy, wifi i havent decided how to connect it, US would be ince but some people want 2 usb ports on the back, mast of the chips are usb or pci so it looks like 1 usb port (use a hub) but i need examples of chips with linux drivers to make an informed descision, it seems the Z**** (cant remeber exactly ) is supported as albeter is using one so mabey thats the chip to use

[speculatrix]

Both multimedia and math use floatingpoints a lot, so the i.mx31 would kick xscale ass in that department with its vfp unit (as would an omap3)

I think this might be one reason why Skype didn't come to the Z - echo cancellation on telephony needs enough power to do DSP-like things. I tried using my 6000 with kphone/pi and without a headset it *really* sucked.

Using the Z as a AVO meter and 'scope would also benefit from maths crunching, whether to do true RMS readings or FFT. low-power math copro would also reduce power consumption for mp3, mpeg2 and mpeg4 movies.

[stampsm]

I am happy to do an xscale board but not at $120 per cpu, plus i prefer the intel 2700G as its a much more capable chip and easier to interface to as well as bieng well documented with publicly avalible infomation

but i have a feeling that this chip is in a class in terms of performance, the inbuilt vide (dual head), Open GL support (not the cut/enhanced down ES), MPEG4 encoding and decoding acceleration with post and pre filtering (such as deringing which is very cpu intensive) and floating point all coupled with a high performance bus (the xscales performance is rapidly reduced on IO and mem tasks) and ddr 266

so basically this 1 chip multimedia wise should blow the 2 chip soulution out of the water in terms of cost and performance, BUT i dont have any numbers to support that, i am going on the technical details i am reading in the referenc manual of both, beta player benchmarks, technical analisys of the xscales performance for difrent tasks and gut feeling.

i dont want to sound stuck up but those are what ihave bassed my desicion on, the price and avalibility being huge points.

speculatrix: for the audio stuff it has been discussed already and we came to the same conclusion to use a breakout box, i might be able to route spdif out oh one of the headphone jacks but only if i can place the spidf in a high impedence state (effctivly turning it off), were you asking for spdif in or out or both or both at the same time because if we have 2 headphone jacks we could have one for in and the other for out

both jacks will be 4 ring and will be left, right, microphone input/3rd sound output, gnd as there is only 2 adc's on the chip, i might change it to allow you to have it setup up as 3 outputs or 2 outputs and 1 input where the input can be taken from any ring bar gnd

those pics are nice but the way i look at it that would be a medium density desin (the mother board that is), i mention that because there are alot of people who dont think we have alot of space, if you have seen a HTC phone design then you will knom the density i am talking about

back to the main topic, bluetooth i think would be best on the full speed usb port as that port is effectivly useless in my mind (not enough speed for 802.11g) so connection of that is easy, wifi i havent decided how to connect it, US would be ince but some people want 2 usb ports on the back, mast of the chips are usb or pci so it looks like 1 usb port (use a hub) but i need examples of chips with linux drivers to make an informed descision, it seems the Z**** (cant remeber exactly ) is supported as albeter is using one so mabey thats the chip to use

here is a quick chek of this for some who dont have the time to look this up

pxa270 processor $60
2700g video chip not sure but i would say since it is intel about $20-30


i.mx31 $20 including the video chip built in, wich looks as powerful or more powerful that the 2700g plus built in floating point for even more increase in preformance.
opengl (goal to run quake 2 at 640x480)
Mpeg decoding: Ever try running even low res mpeg video on a 5600? with mpeg decoding and floating point should be able to run dvd quality video at 640x480 resolution.

the wireless chip you were looking for was the zd1211. it has open source drivers and is used in alot of products. it supports serial, usb or direct memory bus interface.

[Tom61]

It seems Spark Fun has some decent tri-band and qaud band cellular packages, though you need a separate SIM card slot and antenea for the ones I looked at:
http://www.sparkfun.com/commerce/categories.php?cPath=66_68

BTW, how do you deal with getting all the different components to the place that assembles the board?

[Da_Blitz]

they buy the parts on your behalf os if they have others buynig the parts they order in bulk

i still have to check if they can get the parts so thats why i am trying to finalise a list of chips so i con send it off to check avalibilty. the other soulution is design it and then sell off the design under a diffrent licsenee to a manufacturer or OEM with the provision that hardware be made avalible to us at slightly above cost and so we dont cut into thier profits the list of people to buy at the reduced price would be anyone on this board who signed up before x where x is the release date of the product or a better scheme is if you own a Z,

but thats far far in the future at the moment i want to finalise the chipsets we are using

[dhns]

What about using http://www.linuxdevices.com/news/NS2654180137.html as the starting point?

-- hns

[ced]

are you going to build something like this:


...Sony Vaio C1 series...

[Da_Blitz]

Those guys dont have an actual product and there are many other boards that are better suited te bo a pda that have been mentioned elier, in fact the other arm board linked on the linux devices frount page would be more aproprite

[speculatrix]

are you going to build something like this:


...Sony Vaio C1 series...

I must admit, the C1 is quite a nice machine, but fetch quite a price premium for their age and performance (equivalent to P2/400MHz, the later Crusoe models simply had lower battery life). Shame Sony didn't carry on developing that range. The Sharp Muramasa Mebius (dropped a while ago), and the Flybook are still the smallest ultraportables by quite some margin.

[Ferret-Simpson]

We have 3 USB ports, apparently ALL high speed.

One of them supposedly supports OTG. I say we make that our External port, since it will run in Client mode or Host mode, depending on what's connected, like the 3100.

Wireless has to be USB, because we're leaving the Memory Bus for our memory. (256MB DDR266, remember?)

I still say we sacrifice some speed and put the Bluetooth chip on SPI serial, because 115kb is fine for a bluetooth headset, and Mobile Phones are no faster than that. (On that note, neither are most PDA's) - Which would mean we could have a second USB external port. Either that or we put the Bluetooth chip on a 480MbPS port, which seems like kind of a waste to me. . .

Be careful with these Audio sockets, too. Remember we still have to be able to plug in a Headphone jack into one, and a Microphone jack into the other when all's done and dusted: The reason I mentioned a breakout box was to avoid any worries about ridiculously overcomplicated socket assemblies.

Hmmm. . . Anyone want to work on a Linux-Powered Freescale Dragonball wristwatch as a companion to this? XP

[Ferret-Simpson]

http://www.sparkfun.com/commerce/product_i...products_id=757

Hmm. . They've (In the last few days) Added this module. . . The sim card slots into it, it is serially interfaced, and comes with a 640x480 camera. Unfortunately, it appears to be designed for use as part of "Solder together with lots of electrical insulation tape" type projects, since the audio on it comes out of a 2.5mm socket, instead of through a bus connection. Damn.

[Da_Blitz]

USB page 67 MCIMX31RM.pdf (ie the rfrence manual)

USB Host 2 has the following capabilities and features:
  • Is compliant with USB 2.0 specification for operation at full speed (12 Mbit/s) and low speed
    (1.5 Mbit/s)

its anoying and thats why i say use it for bluetooth, they say to use it for a cellular modem and if i can find one that needs usb (ie no serial) i will use it for that, if it has serial then i will only use it if it has 3g and therefore needs the speed

SPI can do ALOT more than 115kbps, i have seen it up to 25Mhz, in fact SD cards use it at 25Mhz (4 bit mode is basically the same exept 4 bit transfers and some other enhancments), spi is a common way to interface SD to 8bit micros, besides these chips normally have a 912kbps serial port for bluetooth that has all the signal lines, 115kbps wouldnt be too godd for a2dp (CD audio) which is what i use

that modem is looking very atractive as i am not really game to put much effert into writing a gsm/3g stack, if i can buy one i would rather do that, latter down the track mabey someone can write one but i would like the hardware to work out of the box and not 3 months latter

audio comming out that way is normal, the sound very raley comes out the serial port in digital format (i could be wrong, think "voice modem") as these things act like modems, in fact if you put a buffer chip between it and the serial port (max232 anyone) then your computer would not know it was a mobile unless you told it,, when you did you would be able to spam^H^H^H^Hsend sms

breakout box would be to convert the 2x4 ring sockets to 3x3 ring for 5.1 or SPDIF, at the moment if you pluged a microphone into one and a headset into the other it should automatically detect the jack settings

Hmmm. . . Anyone want to work on a Linux-Powered Freescale Dragonball wristwatch as a companion to this? XP

all i can say is 8 bit micro with HID profile or remote control interface profile and a graphical driver over the serial port profile on it would be tha way to do it see other topic, they have small chips nowdays

[Da_Blitz]

yeah i finally got quotes working, note the spelling

[morrijr]

It seems Spark Fun has some decent tri-band  and qaud band cellular packages, though you need a separate SIM card slot and antenea for the ones I looked at:
http://www.sparkfun.com/commerce/categories.php?cPath=66_68

The GM862 Cellular Quad Band Module with Python Interpreter at http://www.sparkfun.com/commerce/product_i...roducts_id=279# says...

"You will need to provide a SIM card. Pull the SIM card from your phone, insert it into the module, and viola, you are making calls under your cellular account. Works with all providers currently supporting SIM cards (AT&T, T-Mobile, and Cingular)."

(emphasis mine) reads like you don't need a seperate SIM card slot... not bad for about £65! It is programmable from something 'simple' like python and has camera capability (not, I'll admit, that that interests me particularly).

PS, sorry about the almost duplicate information - I really should read to the end for the forum before replying!