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> Parts List, A rough guide to the chipsets we will us
post Aug 6 2006, 10:11 PM
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Well i have just been doing some research into the chipsets we can use. as you may knom i mant to use as few manufacturers as posible. the reasoning behind this is two fold, it makes things simpler and if we can get one part in small quantities then it is likly we can get several differnt chips from them in small quantities

now that thats out of the way, i have some corrections for some of the hardware, it has been stated that there is an upper limit on the flash and how much we can have in the system, this is untrue. it turns out we can have more but the interface the requires "glue" or in other words extra circutry. what this means is there is a posibility to use the 32Gbit flash chips that samsung has on thier website

one thing i have looked into is the current situation with the DDR RAM, i have made some intresting discoveries with regards to this and have decided to go back to using mobile DDR RAM only instead of offering the normal ram as well. this puts a cap on the upper limit the design will have, effectivly limiting it to 256MB (4 chips) the reasoning behind this is that the 1Gbit chips were twice the size of 2x 512Mbit chips and consumed more power, the funny thing is that depending on how it was wired up 2x 512Mbit would consume more power, however we would need 8x chips to hit 512MB. this may sound wierd to go to the solution that has the potential to chew more power but with a couple of tricks it can be made to use as much power as the 1Gbit chip

we do this by using 32 bit chips rather than 16 bits, with the 16 bit chips we would have them in parrallel to make a 32 bit bus to keep the performance up. instead we will have the chips one after each other so that unused chips can be put in a low power state. now this iswhere the low power chips are really good, unlike thier PC targeted cousins they can be put into an ultra low power state where they dont refresh thier memorey contents, the power consumption in this state would barley light an LED. unfortunattyl i dont think we will be able to take advantage of tis feature due to linux's cacheing system and how linux allocates memorey (basically we would need to defragment the memorey to try and use as few chips as posible)

the other advantage the mobile chips have is that thier normal power requiremnts for most tasks are lower than normal chips, when not acsessing the contents of one of the chips it can be put into a low power state saving power blah blah ... you get the point.

Now at this point you are all probelly thinkin, "well he is talking about ram and power why didnt he put it in that post about saving power by turning off LED's" well here is where i start talking about the design decisions behind which chips i have selected.

first up is the HDMI chipset. now this is a bit contravesal as it includes encryption but what you porbelly dont know is that its backwards compatible with DVI, however it is most likly compatible with VGA (even with an adaptor) so a second connecter will have to be put somewhere. thu adavantag the HDMI gives us is that it transmits both videa and audio, meaning we will be able to put that 7.1 chipset that has been mentioned to geed use, it also supports SPDIF which has been asked for.

this chip is great for us because it takes a VGA signal and gives out a HDMI compatible signal, it handles the encryption and everything else, as far as i can tell all we need is a key and perhaps not even that (besides you could always "clone" the key from your HDMI DVD player) the funny thing is because we have the chipset bieng fed by a vga signal we can route that to a connector and have good old VGA support. nice and simple no software required.

next we come to bluetooth, part of my "minimum spec". as i have said i wont to use a enhanged data rate chip, the reasoning behind this is that it is lower power. the anoying thing about this is that it needs an RF shield which means more things to manufactuer. the solution, buy a prebuilt module from infeon that has the RF shield built into it. nice and samll and is basically an "attach an antenna" design that also offloads part of the processing (up to HCI it says)

now for another explanation of some of my design decsions. i am trying to use single chip solutions to reduce the cost, both in terms of cash and board space (mostly board space). lukily for us neally ever second generation chipset for every RF protocal you can think of has a single chip solution.

back to where the story left off. i know i am running out of serial ports (async and sync (SPI and ttl rs232)) however does anyone fancy a gps reciver, i have found a single chip solution that looks very nice and also reminded me that phones are supposed to come with GPS so that you can be tracked by "emergency services" [begin silent wisper] or the CIA/NSA [/end silent wispering]. now i would like to be as complient as posible so i might have to include a chipset like this, however we are running linux so i recomend you setit up to tell them you are on the moon smile.gif. more seroslly thogh it would not be hard to make it report a location under user control if you are that scared about it, and it would nicly round off this design

ok the next one we have is very very nice, infeon also make phone chipsets based on arm up to 250Mhz. not bad at all, the advantage is that this thing has serial ports on it and can help us extend the IO of the iMX3. it can also be used to offload part of the processing of whatever we desire as well as allowing the phone to work without the iMX3. it supports multiple antennas and HSDPA so we can get stupidly high download speeds. We could build a PDA around it if we needed

the problem is that nearly everything is a single chip solution so it will be hard to find a chipset without the ability to hook up a screen and keypad. it does mean that if we needed to we could have 4 SD card slots smile.gif. i am thinknig that this should be connected to 4 buttons and the mcrophone/speaker as well as a gpio line from the iMX3, when the iMX3 drives the line high the chip knows that the iMX3 should make all the descions otherwise pickup the call when the button is pushed, i would also connect the secondary screen to this processor as it would mean that we could display the incoming number when the iMX3 is unavlabile to do an adress lookup.

this is by no means complete, it still requires alot of thenking on how to design the solution, the actuall problem hasent even been outlined yet (i wiill leave it until we have all the hardware decided)

i am also thinking of micron for the actuall image sensor, how many mega pixels do we want?

flash is flash, i am thinking of using samsung beacuase of the insane denisities they have

anyway hera are the links to the hardware i have been talking about:
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post Mar 19 2007, 02:36 AM
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so as promisedi am designing the power supply at the moment however some other chips poped up that could be nice

Return of the finger print reader: http://www.atmel.com/dyn/products/devices.asp?family_id=609
allows for psedo mouse support (its basically a laser mouse with a wierd sensor)

anyway back to power, at the moment i am looking at getting a power supervisor, the davantage of these things is they pack alot of diffrent power regulatiors for diffrent pourposes, they are small and can be heat sinked eaisly and they normally pack extra goodies (the freescale one has audio in and out, a RTC, power on at certin times of day, lithium ion charger and a USB PHY that supports client and host, but requires an NDA so it wont happen sad.gif)

the design spec at the moment is between 5v to 18v input, if you dont want to care about polarity then i could add a rectifier however most chargers are "standard" and use the same polarity and the regulator is just waste heat and board space, if you dont trust yourself to get the right charger then charge over usb.

current wise i am looking at at least one chaneel that can do 1A @ 5v for USB, for the rest of the support circutry i am unsure, it depends how i partion the devices however there will most likly be a .5A for the cpu and .4 for the RAM with .15A for several of the extra chips (ie audio, bluetooth). i will make sure wifi gets the power it needs wink.gif

i will try to give each subsystem its own regulator (the chips i am looking at are 7 channel) so that you can fully turn off any subsystem you are not using (audio comes to mind)

one thing i may be able to swing is a proximity detcetor for the keyboard, using the backlight itself, LEDs can be used as solar cells, yada yada yada, look on hackaday.com for more details

for refrence i like the natinol semi LP3941A, it does the full LED driver, I2C programability and has backup battery support as well as Liion charging and its 11 channel !!!! (http://www.national.com/pf/LP/LP3941.html)

one thing that has come up is that this will be mainly a 3v system, so any I2C connections on board will be 3v, however i may be able to swing it to the 5v usb line to make them 5v, not really much of a problem due to the nature of the bus but it could play havoc if you dont get the voltage you were expecting (meeats TTL requirements but not cmos off of the top of my head or the other way around)

the natinol has a problem in that it cant go above 5.5v so it would be a 2 chip solution (not really a problem, it only means i need to put an extra chip between the power plug and this thing so that regulator would be off most of the time)

apart from that the natinol semi chip is rock solid and requires little in the way of extra parts, 4 ar required, then one capacitor per Vout, so its safe to say this part is done

check the next post for whats next
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post Mar 19 2007, 12:53 PM
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QUOTE(Da_Blitz @ Mar 19 2007, 11:36 AM)
and they normally pack extra goodies (the freescale one has audio in and out, a RTC, power on at certin times of day, lithium ion charger and a USB PHY that supports client and host, but requires an NDA so it wont happen sad.gif)

don't entirely write off the chip - the NDA might only be temporary if it's freshly out, as they may simply want to track who's trying to use it to ensure that any changes to the device can be tracked by customers.
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Posts in this topic
Da_Blitz   Parts List   Aug 6 2006, 10:11 PM
speculatrix   Linear Technology have created a very useful power...   Aug 8 2006, 02:19 AM
speculatrix   For audio devices, Micronas have some very sophist...   Aug 8 2006, 02:32 AM
Da_Blitz   more than likly we will have a linear devices chip...   Aug 8 2006, 09:23 PM
speculatrix   FYI, Ironwood do all kinds of interesting adaptors...   Aug 25 2006, 06:42 AM
Ferret-Simpson   I'd like to make a point. Now that I have PDA...   Aug 25 2006, 08:15 AM
Da_Blitz   actually the ability to make a call without the cp...   Aug 26 2006, 06:15 AM
Ferret-Simpson   If we're connecting up to the full keypad then...   Aug 26 2006, 08:06 AM
Da_Blitz   i have always thoght that video aclls were a bad i...   Aug 26 2006, 04:23 PM
adf   . to be honest I'm not that keen on the camera...   Aug 26 2006, 04:38 PM
Ferret-Simpson   The camera oesn't have to be perfectly still. ...   Aug 27 2006, 02:44 PM
Da_Blitz   mm, i do hate calling people to begin with, and i ...   Aug 28 2006, 03:08 AM
Da_Blitz   just came across some more info, turns out freesca...   Sep 9 2006, 09:16 PM
Ferret-Simpson   So. . You're an Anthropologists Nightmare, or ...   Sep 11 2006, 01:31 PM
adf   QUOTE(Ferret-Simpson @ Sep 11 2006, 09:3...   Sep 11 2006, 07:09 PM
Ferret-Simpson   nonononono! I'm NOT saying we shouldn...   Sep 12 2006, 12:32 AM
Da_Blitz   we have to start thinkning internationally (esp. f...   Sep 12 2006, 01:02 AM
adf   what I have now (though it clearly needs better in...   Sep 12 2006, 09:45 AM
Ferret-Simpson   In terms of licensing stacks etc. . This is proba...   Sep 12 2006, 12:12 PM
adf   QUOTE(Ferret-Simpson @ Sep 12 2006, 08:1...   Sep 12 2006, 12:16 PM
Da_Blitz   well the funny thing is that the phone on the PP w...   Sep 13 2006, 03:22 AM
Ragnorok   - I'm with adf ... camera is a lark. My curre...   Dec 6 2006, 07:18 PM
Da_Blitz   Yeah i find it handy every now and again (i finall...   Dec 6 2006, 11:54 PM
speculatrix   http://www.cieonline.co.uk/cie2/articlen.a...d=148...   Feb 23 2007, 08:05 AM
speculatrix   How about this display? 7" TFT at 720 x 480 ...   Feb 25 2007, 03:36 PM
stampsm   i just managed to pick up a sl-6000 for a good pri...   Feb 25 2007, 10:02 PM
wsuetholz   Here is a new chip(set) from Broadcom that integra...   Mar 16 2007, 12:04 PM
Da_Blitz   those chips look great however both are linux host...   Mar 17 2007, 04:34 PM
stampsm   try to just get a datasheet for any of thier parts...   Mar 18 2007, 09:24 AM
Da_Blitz   so as promisedi am designing the power supply at t...   Mar 19 2007, 02:36 AM
speculatrix   QUOTE(Da_Blitz @ Mar 19 2007, 11:36 AM)and th...   Mar 19 2007, 12:53 PM
Da_Blitz   ok i decided to lump a couple of things into this ...   Mar 19 2007, 02:39 AM
Da_Blitz   Ok found this from cypress: http://www.cypress.com...   Mar 19 2007, 04:44 AM
Da_Blitz   well considering the imx already has a RTC built i...   Mar 19 2007, 05:52 PM
Ragnorok   - Could we bump the battery capacity or is 2Ah all...   Jun 13 2007, 05:12 PM
Da_Blitz   i had an idea or two to put a large battery in the...   Jun 13 2007, 10:14 PM
Ragnorok   QUOTE(USB is in suspend mode when the handheld is ...   Jun 14 2007, 06:25 PM
Da_Blitz   but why would you want the usb module to be on if ...   Jun 15 2007, 03:47 AM
Ragnorok   USB: The specs made it look like the unit is offli...   Jun 27 2007, 01:13 PM
wsuetholz   Fujitsu E-Paper Display This would be so cool to ...   Jun 28 2007, 09:26 AM
wsuetholz   QUOTE(wsuetholz @ Jun 28 2007, 12:26 PM)Fujit...   Jul 13 2007, 11:09 AM
Da_Blitz   wireless is good because its convinient, but i do ...   Jun 29 2007, 04:55 AM
Da_Blitz   looked at this thread for some refrence material a...   Aug 25 2007, 06:04 AM
speculatrix   great, so when can I buy a PP?   Aug 28 2007, 02:34 PM
Ferret-Simpson   According to the original timescale, about 9 month...   Sep 15 2007, 02:28 AM
Da_Blitz   seems you had diffrent ideas to mine btw i am a h...   Sep 15 2007, 07:01 AM
wsuetholz   Just to put at bay feelings of this sub forum...   Mar 4 2010, 07:51 AM
speculatrix   I have been wondering whether the netwalker PC-Z1 ...   Mar 4 2010, 11:12 AM
canguy247   QUOTE(speculatrix @ Mar 4 2010, 02:12 PM)...   Mar 5 2010, 04:02 AM

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