Build Your Own Linux Powered Pda

[Da_Blitz]

[qoute] Looks good! If you go the CF/PCMCIA route, it might be easiest to have headers one behind the other, and then have the company that populates the board put only one connector on.[/qoute]

yeah thats what i am thinking of doing but if board real estate is at a premime i might chose the pcmcia and let you use a pcmcia to cf adaptor

for battries as i said i am only making the board however lookinng at all of this it might be a good idea to prouce one design that fits in the exsisting cxx00 case as you can buy the case seperatly and that means you can use Z battries

you are right about the mobile phone processors, we will most likly talk to it ove a serial port rather than have it built into the chip or mem mapped, this means nice and simple At commands to control the phone and also means we dont have to write software

the gsm is more of a minimum spec however we do have a problem in that each contry uses a diffrent system, i might point out that i also live in australia so its in my best intrestes to make it compatible with whatever we are using here that said it shouldnt be too hard to adapt it or even have plugin cards so you can swap radios (this would also make the board desin simpler)

probelly wont have solder points for everything, mabey a couple of things and the mem bus (thats already 98% of what you need) but i think it will be more like: i want this hardware so i "port" it to the design, reroute (equivelent in software terms would be compile) the board and then get it manufoctured and populateed by a company who returns your design to you in about 3 weeks that way i can jam pack the design

note that doing it that way is really for new hardware, if you want for eg to add bluetooth then there will be a solder point for it only the more exotic stuff will be missing

actually i was thinking sharp would be a potential buyer of the board and would help drive down costs or we sell the design to them under a diffrent licsence (as i want to do a GPL type open hardware design)

I have found a place that sells Xscale chips in small quantities but the iWX3 is ALOT cheaper and has video acceleration built in as well as DDR ram support and a floating point unit so it would take alot for me to switch back to that chip

the chip is also used in the toshiba gigabeat in case any one was intrested about the sutability of this chip

the one thing i forgot to mention is that i also want the ability to turn this into a thin client so on board ethernet might happen or might be limited to the pcmcia slot but it does garentee usb slots and VGA out

this chip also hhas the same problems as the intel in that the pcmcia and cf intreface are shared weth main mem so i am looking into alternatves for storage eg huge flash capacities 2GB max can be done with one chip thanks to samsung and also support for ATA drives (laptop HD anyone) with the ata stuff you may be able ta have a mem only CF slot and a IO capable one, the advatage being that the mem only one will not cause a decrese in performance as it has its own mem bus

touchscreen dosent affect me as i use the console but of course i will add support for it

i might add a loptop ram header so that people can make daghter cards and plug them in, and because it will have the data bus signals it would be posible to add more ram (of course you would have to make a board to take the ram, you cant just put laptom mem in it)

will try for transreflective if i can but i am not making  anything but the mobo, i would like others to help with this espesially if you have design skills or if you know where we should look as for electrical people if you know any and they are intrested get them to email me at jaycoles (a) yahoo.com and tell them to include the word ilnux in there message (to bypass my spam filtering

with the price i fugire that you would want more funcitionality at the same price point but if you dont want those parts then i will tell the manufacturer to not solder them on the board

the fpga is there for glue logic rather than use an asic to basically cut my dev costs, they chew throgh power so i would probelly use a cpld instead but might have a fpga avalible as a add in card for devs and hobbiests (eg software defined radio for fm reciver or ham radio)

Ram Max is 256MB so thats plenty, i think that can be done with 4 chips as well so net much real estate for BGA parts

i would really like to see an open hardwae company, at the moment i am working on a project for gensis who make PPC boards and are VERY linux friendly to the point where they are writing XGI graghics card drivers with the 2D open source and the 3D closed because of NDA however the will compile it if you need it and will show you if you sign a NDA (i know its a pain but its not bad) the other thing thats nice is the hardware they have avalible online to play with and the hardware giveaways they have (they are the reason i found this chip)

[Da_Blitz]

WOW thats long

[stampsm]

if i was designing a pda here would be my basic design plan

-the case design would be a real hard decision since there are fans of both clamshell and regular pda design. if it was my decision i would most likely go for the zaurus CXXXX clamshell with tablet folding capability because it seems to be more versitile and easier to integrate a built in keyboard

-ARM processor at least 400 mhz preferably 500-600 range or at least capable or overclocking to that range

-lcd display of at least 320x240 but strongly suggest 640x480 size (try to avoid odd sizes such as 800x480 since that would most likely cost more since there would be less of a demand in the market for that size of display.) touch screen of could would be needed. the size i would look for would be in the 3.5" to slightly over 4" range

-external memory slot in the form of at least 1 CF possibly 2 CF if the chosen processor already has 2 ide channels built in. add a sd in at least mmc 1 bit mode or better yet 4 bit mode since it gives cheap memory expansion in a small size for very little I/O cost

-when it comes to the modern connectivity way of life i would strongly urge to add wireless capabilty with preferably bluetooth and wifi. the wifi capabilty may be best to keep with a CF card if two CF slots are availible. the cost is quite low for the user to add and it gives the option to add a cf wifi card with wardriving features such as external antenna. the bluetooth is an option that should be added to the board even if it is not populated so the user has the option to add it latter or have more than one hardware model so those who do not use bluetooth dont have to pay the extra cost.

-when it comes to ram 64MB is the bare minimun and 128MB is what i would suggest. better yet some memory ic chips have 64MB and 128MB versions in the same footprint so you can have one design with a possibility of two different memory options. better yet if you could find an affordable memory ic with 64, 128, 192, or even 256MB options in the same footprint that would be the best choice.

-when you look at most rom distrobutions 96mb is the lowest i would put in a newer pda since that can easily be filled up. better yet is to use a 128, 192, or 256MB footprint compatable ic in the design like the ram to give more flexibility.

-an integrated keyboard is a must especially in a clamshell design

-built in headset jack and built in microphone/speaker is a must

-USB on the go is a must and since alot of usb devices need a good amount of power i would recomment an optionable external battery pack be designed to be able to clip onto the bottom the the pda to allow longer battery life.

-i can see IR ports being taken over by bluetooth, but i would still include it. as a hardware hacking freindly feature i would design the ir module to be disconnectable and allow a plug to be exposed that could have something else plugged in.

-follow the "if you dont use it dont cover it up" idea. basically if you dont use a pin or line pull it out to a contact pad and document it.

-all most forgot this one. you need a serial port for linux use.  

-jtag port pulled out in an easy to use way (dont nessesarly add a header pin to plug it in, but at least have the possibility to add one

-ohh and a gift for the hardware hackers.    a cpld/fpga on board with all or most unused or even some used lines run through it for customization.




the hardest things to deal with for this in my opinion would be the display at a reasonable cost.  

my case design would most likely be a clamshell with a CF slot on either side and the  SD, IR, and usb connectors in the front. and the audio and docking connectors in the back. on the bottom i would have clips for holding an extra battery pack and also expansion plug on the bottom like some laptops have for extra accessories such as a docking station like stuff


    ok it is 1:45 here so i should get to sleep i think i got all my idea out, but i might have missed a few.  

[stampsm]

well LOL i see someone was also typing a long reply the same time i was

[stampsm]

i would like to add that i like the idea of the freescale i.mx processors. they make really nice stuff at freescale and are quite liberal with samples for working with (can you say free cpu's to build prototypes with ) the i.MX31 processor has a nice 3d graphics accelerator built right in with OPENGL ES support including drivers and libraries.

[Ferret-Simpson]

And good choice on your Zaurus! POODLE LUV!

If we've got an open board REFERENCE design, then any GPL based company (Hardware Fedora/Mandriva anyone?) can modify that as long as they give the schematics free. XD

GPL hardware seems to be a more profitable thing than GPL software, so I can see a company based on it doing very well, since there aren't many people who are willing to scratchbuild a system.

I think building a retrofit board for a Zaurus isn't the best idea, because the zaurus parts, while available are quite rare in some places, inclusing the UK. It might also be cheaper to have someone press Aluminium cases for example, and there's still the point of a funky logo. On which note, this concept needs a name and logo! If you're doing motherboards, I can see a collaboration with a couple of other community members to make a full PDA.

There are some very small self-contained serial IRDA components out there, so I can see it being feasible to build a hotpluggable connector for IRDA which can be unplugged to leave a Serial/JTAG connector (Why the hell would you need Serial and IRDA simultaneously anyway? RHETORICAL.)]

WOAH! 530mhz? Sweet!

Does a microdrive have a Standard ATA interface? Apparently We can expect 20GB drives either this year or in 2007, so If it's possiblee to include a Microdrive compatible interface that's great. ^^

2 MMC/SD ports: If we don't take advantage of that we're insane. Anyone know a place that does 2-port PCB-mount SD sockets? Either that or it would be worth the space having them parallel. Internal Storage, plus 2x2gb SD. Anyone know if they're SDIO capable?

The disadvantage of PCMCIA is it's mooch bigger. Agreed, it would be nice to be able to plug in a 24/96 12 port digital rec. . . I VOTE PCMCIA!!!! O.O |NOSEBLEED FROM EXCITEMENT|

A Quad band phone will work anywhere. If we can get a Quad Band GSM/GPRS processor onboard, that gives everyone worldwide access. W-CDMA is nice, but it's expensive and not well supported. If we're really desperate, we can always put in a Vodafone PCMCIA card.

But yes. The i.Mx31 is looking to be a pretty good chip!

One final note: A few people have mentioned Cameras. . . If we're making a universal/Spitz clamshell design, I don't think we could go wrong with a camera mounted next to the screen (In landscape), below it (in portrait) since the i.Mx has an inbuilt CMOS/CCD interface. That would allow VoIP, as well as limited photography. The only other design I can suggest for it would be a rotating camera on the edge of the screen, with a 180' swivel.

This would allow camera usage for both conferencing and picture taking. It's either that or USB webcam!

I'm also with the note on TFT panels. 800x480 is just silly. We'll make it harder to get parts, increase the drain on system power and processing capability, for a fairly minimal gain. It's much more important to have a simple useable screen, similar to that of the CXXXX series Zauri, which is perfectly good! XP Besides, if there's going to be some form of External monitor connection, There's not really alot of point!

Finally, I vote for the name "PocketPenguin."

[Ferret-Simpson]

Forgetting things AGAIN:

Dan, Why the HELL do you need a 800x480 to watch DVD's?

The best quality DVD's available are 640x480 anyway.

Maybe when BD is out. . . But I doubt we're going to be hooking BluRay up to a Zaurus-Type anytime soon. . . Maybe December time?

[Da_Blitz]

Yeah a camera would be nice but i would put it on my first to be droped list if i run out of space the nice thing about it is the image processing unit that fixes up the image the os even sees it (eg color space conversion) this means higher framerates and lower cpu usage

seems audio is a big thing so definattly 1 headphone and 1 microphone on seperate jacks what i was wondering is for the video out, do we want VGA a tv connection HDMI (nice small plug there) and what type of sound capabilities eg 5.1 (ok i am dreaming but keep in mind that i can chuck that in if you want a portable media center) as for 24/96 thats why i boght an audigy usb sound card, but you need usb2.0 to use all 8 channels at that setting (whigch the cxx00 dont)

i was thinking about dvb-t but as we have usb2.0 it dosent matter about bandwidth (see OZ fourm for original post)

i want a list of everything thats posible so i can put up another list that i have gone throgh so people can vote on what they want, keeping in mind i will have final say scince i only plan to produce one then make the plans avalible

it has support for 4mbit irda and i thoght i would throw in CIR to get a longer range so you can use it as a remote

ill just clarify somthing because many people seem to be ignoring it, this is a project to build a mother board, i am not doing cases or LCD screens however i may do a keyboard design, i fuguire someone else is better connected than me in that area and could help out. it also means multiple case options  i would like to see the sidways slider format with backlit keys in carbon fiber with a laser etched logo, plus i would love to see the return of the compaq backpack idea and am willing to add an IO header for that (mabey instead of the addin card)

quick price guide
Xscale chips (any of them) $100 or more
iMX3 $20
guess theres no competeion here, both are for small quantity prices and as i said, i have now found sources for both, the free cpu's they have have no video acceleration however the chip is so cheap i dont care

good point about JTAG, i would list that as critical scince thats how i would want to loda the inital firmware, and a serial port is a definit, would you like TTL levels (5v needs external converter) or rs232 levels (12v inverted)

i had an ide about the secure boot, get it to boot into a kexec capable kernel and then have that verify the kernel it is about to run using gpg and a public key, easy to implement and means easy security (of course you dont have to use this feature) best bit is if you burn the public key into the ROM itself to prevent tampering. i think this will be for the hardcore only but it fits well with the camera and mabey a finger print reader to do iris and finger print recignition

names are a good start as they give it a "feeling" or spirit, unless anyone thinks of anything better i am offically calling this the Pocket Penguin Project or PPP

SD thats a good idea i only really planned for 1 but i could add 2, they are SDIO capable if i rebebr corectly but we need drivers and a generic sdio stack, i belive the stack is posible to write without offical documentation and the wifi drivers could also be eginered in time, but we could shortcut this and buy an exsisting stack (about $5 per device if i remeber correctly) but apart from the bluetooth card i dont see the point and scince bluetooth is onboard there is no point (i might clarify i had a sandik sdio wifi card and several CF wifi cards, the CF ones get 4x the range and alot more speed (mainly due to the better signal) i also had that card degrade to the point where i could not use it anymore (refused to be recignised) and this was 5 days after it was out of its 1 mont warantey)

should we set up an IRC channel for a meeting some time it would be a good idea to flesh out these ideas some more

yep microdrives are ATA compatible

[Ferret-Simpson]

Never used IRC. I think sticking to Forum is better, just for us reets that wouldn't have a clue.

I've been sketching out a generic case design based on the clamshells, just a weeny bit bigger. (I know you're not looking at a case, but to we have everything in the same thread would make sense until some bright spark builds a website. - NOT ME! My server won't boot.)

In my design (Pointy corners, all the hallmarks of an Alpha) I worked around a base design of 126x14x65 (NOT including Screen or hinge - I didn't want to estimate a depth on that) which managed to squeeze 2xSD 2xUSB IRDA, HDMI, Dual 3.5 audio and an Aerial socket for a wifi antennaon the backplate, with the PCMCIA socket running alon the bottom of the case and opening up on the right hand side (In landscape mode) so it would poke out the top in portrait.

I did a basic design for the top of a screen panel, with stereo speakers, (The kind that look like   (##)  as seen on the Uni)

as well as a rotating camera, on the right hand side. based on a Samsung camera on my Mum's mobile, which seemed to work.

My design left the front panel of the Base unit (Landscape) free for say. . a scroll wheel, and maybe a power or docking connector - Someone mentioned a Powered notebook HDD "Backpack"? which could have it's connector behind a panel on the front.

Only thing I did find, was that with the PCMCIA card there wasn't much room for a battery. . . Since the motherboard will take up the better part of the case, It might be better to lose the PCMCIA in place of a CFIO? A PCMCIA card, socket, and a 750mAh nokia battery took up the whole of the bottom of the case, up to a third of it's depth. . . I don't think we could fit it all in a reasonably sized PDA, and the space on the motherboard for the socket would be better used for onboard Wifi and Bluetooth chips, and all internal storage being onboard flash - A microdrive is quite big after all in a device this size. besides, after 1xCFIO and 2xSDIO. . How much more storage could you want? Even if you're using the CF for something strange, like a 3g card, a 56k modem, or a 10/100 - There's still two SD sockets. for up to 4/8 gb storage.

My refined specs (IMHO) that I looked at after running a design up are:

iMx31 530mhz/133mhz
128/256mb DDR266
4.5" TFT fitted nicely, 5" is getting a bit too large, although if it's all we can get, it can be done.
Separate 3.5mm Line in/Lineout (Or mic, depending)
2xSDIO
1xCFIO
1xHDMI
1xIRDA
2xUSB480
1xCamera - We'll have space in the screen panel for a rotating camera, and it'd be a waste of a good chip function not to include one. ROTATING, to use as Camera and VOIP.
1xEXT wifi Aerial socket. - If people prefer internal that's fine, but several people have added external sockets to their PDA's or cards, maybe a simple folding aerial like on most Routers and Desktops would be worth it? Or maybe just put an internal and a socket?
640x480 Res
NAND Flash - As much as we can fit in there really, I can't see how we can get a CF or MD on a PDa size mobo with Phone, Ext-CF, SDIO
Quad-band GSM/GPRS phone, so we can all use it. ^^
STD mini-Sim socket, as used on every mobile for 12 years
Camcorder-battery Larger than 1500mAh, or if vertical space gets to be a premium, maybe two smaller Phone-types?

APM: Alot of this stuff is going to be big on power drain, so it has to be possible to Software-Power down at least the Wifi, Camera and Bluetooth, and Possibly the phone, too.

We've got a generic geek who can make what are only just unreasonable demands (Me.)
A motherboard Guy (All hail Blitz!)
A name (Of unknown popularity)

What we need, is someone who can seriously look at a case design, and maybe somewhere to manufacture them? When I was making my rough sketch design, I was thinking a ?pressed? Stainless steel or Aluminium shell, about the thickness of the average credit/debit card? (2/3mm)

Just so you know, I based my motherboard size expectation on an ipaq 3950 motherboard that's lying on my desk, (PXA250) and a DragonballVZ-33 from a clie (Which is TINY! o.O)

Since I'm guessing your average Moto-based board will be slightly smaller than say the iPaq board, because of the greater number of integrated components. - My Stacked SDIO idea came from a multilayer board with one conn. on each side.

[Da_Blitz]

Ok got it dropping the pcmcia and making it a backpack

for the board i was thinking mabey even 2 boards staoked ontop of eachother as this would then be about the higet of some of the connectors and gives us huge amounts of real estate this would allow the 2 SD cards above each other, also i hope you estimated full size usb ports as i hate adaptors, plus if you put it on the back it would be great for a docking station

the layout as i see it is CF on one of the shorter sides (left most likly), headphones on the other (headphone and microphone/headphone so 2 or 4 channel depending on settings) USB along the back (at least 1 usb mini socket, if there is room 2 full sized sockets), irda on the back (makes more sense there) and hdmi on the back (for the docking station), antenna will be female and an the back so it sits flush and you can use an adaptor, backpack connector ethier into the CF slot (CF and pcmcia are just diffrent sockets and current draw) or a connector next to the headphone jack

check out the cassiopia for form factor, i have one here and it has a full pcmcia slot and isnt that bad apart from bieng a bit big, i think we might end up with several diffrent form factors at the end of this for a couple of reasons, i would like to see cheap arm "blades" as well, ethernet, 8MB of ROM and 256MB of ram and nothing else so that i can have a native compiling cluster to work with and considering the price of the chips and how integrated they are it would be about half the size of a credit card and would be handy for inital dev work (a cheap platform to test drivers, for devs)

i would drop the rotating screen but am open to leave it in (i never use it or the touch screen) leaving it out simplifies alot of things mechanically and electrily

thats what i imagine anyway, mini sim is a must, wonder if we can use its security features somehow

good point abot the antenna, i agree tat that is a must and would be required if we use a metal case

we need a thick metal case in my opinion as i dent them fairly easily' if its metal i could also use it as a heat sink which is a plus (not sure how hot they get need to check power consumption)

i havent looked at power consumption yet but i would like to stay at around the 2Ah mark as it is a good size and fits nicly with the double boards

it would be intresting to take this design and make it into a long life laptop as well as it has the media capabilities, by keeping it flexible we could do this and these cpu's use 1/10th the power of a laptop (based off xscale power consumption)

i hope to have a website up soon for several resons so that should not be a problem

apm is a must hoever i think that dynamic power gating and freq scaling are very important as well

[Ferret-Simpson]

I actually think the rotating screen is important, because everybody else DOES use it. XP

Actually, I'd say IRDA should be with Audio at right.

Stacked board makes sense, because it means we can make the overall area covered by the board smaller: This makes fitting in the battery easier, because it means we can use the full internal height of the case for a battery. (Except for the SIM socket under the battery Mobile style.)

If we kept the rear of the case simple, Expansion connector, 2xUSB (Stacked) 1xPower (Same as Zauri - 5V), HDMI, that means that other peripherals can be put on other edges, CFIO at left, the stacked or parallel SDIO on the front.

Apart from the electro/mechanical difficulties, the Clamshell screen makes alot of sense, because it gives extra space at a small volume cost, for example the speakers, camera, and (I actually Really like this idea) a Thumbprint scanner could all be on the screen panel while removing space constraints on the main body.

Are those prices USD? If yes, then I can see a cluster being a cool piece of equipment. say 50USD a blade, a cluster of say 10, would give a nifty BEOWULF dev cluster. I take it they'd load the OS over Network? Cool idea.

RS232 Jtag by the way please! XP

One big point, The Aerial socket can't be flush. If you've ever seen the antennae I'm talking about, they have a big plastic surround at the bottom which screws over the connector.

And another thing, what about a jog-dial? It's the one thing about my clie that I really thought was genius. On the front(right) panel?

Also, with a 2A power drain, that gives us less than an hour on a standard battery (1.8 Amphours, 1800milliAmphours)

That might not be a problem on what is basically a mini laptop that's going to be used as a mostly-mains computer, but for a PDA. . . WAAAAAY overbudget. We need to half that with all peripherals on, and get it even smaller with peripherals off.

I'm looking at say

2 Hours (1Amp) with Phone, Camera, Bluetooth, Wifi all on,
8/9 hours Phone only.

http://www.wirelesspro.co.uk/product_info....products_id=332

That's the antenna design I was thinking of.

At some point I'll do a few more sketches of a PDA design. Anyone here a blacksmith?

[stampsm]

try adding the docking connector like i was saying so you can have a docking port or slieve with a pcmcia, camera, and other stuff you could not stuff into the base design availible for those who would want it.

[stampsm]

on that blacksmith point actually yes.  i got a 95% completed forge construction project i am working on in my backyard.

[Ferret-Simpson]

Fancing making cases for the PocketPenguins?

And I'm still hoping we can get a camera on the screen. It's not taking up any real estate inside the body except for the control lines that way, right?

And the expansion connector I was talking about is the connector for the backpack.

[Da_Blitz]

I think you miss the point on a flush connector, what i used to use was a flush connecter on my wifi cards and a female to female adaptor when i needed anything to be connected, this ment that things didnt get caught in the cases i pack everything in, works well

i was hoping to put the fingerprint reader on the board next to the keyboard and have the screen take up the whole face but i guess if we have room then the speakers would go on ethier side, however i agree the cammera facing the user should be on the screen but i belive tha the high quality camera should be an the board itself so you can twist the screen and make it into a normal looking camera (running linux with GIMP )

also i wanted to have a small auxilary screen on the outside of the screen with 4 buttons to control things like music

as i use the thing in lanscape all the time it make sense for me to have it at the back, alse having it at the left means less room for the expansion connector unless i move that to the back (that may be a better way to do it for a docking station) but i guess a compermise is to put it in the corner and make it wide angle, best of both worlds

Jog dial is a must, 2 if i can fit themone on the back and one on the frount so when you have the case closed and in portriat mode you have the screen on the frount with the current song with controls to play/pause and a jog dial on ethier side for next/previos and volume up and down

LOL, 2A power consumption is crazy, i was talking about battery capacity, i am trying to fit in with a power budget of 200-300mAh, this chip seems very low power and by turning things off it makes it easier to achive, the microdrive will break that but its not an all the time so we save power that way

i think its safe to say we can drop the addin card in favor of the backpack/expansion connector

In reference to the laptop and blades i was thinking to have in total the Blades, the PDA and the laptop. the blades would be proof of concept to allow me to have a cheap way to check that all the iMX3 stuff works and allow for a very cheap dev platform, next would be the PDA which is the same as the blade except now i test with new hardware and finally the laptop would be the pda boaurd and an expansion card plus a hard drive in a laptop case

the blades would boot of the network onec every thing is done, i was thinking having a card that the CPU cards slot into (think motherboard and PCI) that has edge connectors with ethernet and serial so you can hot plug them, one advatage is if the jtag port is on that connector then i can use it as a programming interface

the boards bieng so small means i can get them built cheaply, the only problem is that for the minimum order i am looking at mabey 20 of them unless i go thregh a diffrent manufacturere for the prototype

might get a couple of pics up in the next week or so of what i am thinking of, both of the PCB and the case