Pocketable ULTRA-low-powered device with Linux and/or Wi-Fi

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Pocketable ULTRA-low-powered device with Linux and/or Wi-Fi

This is the Ericsson MC218. I happened to discover one in an op-shop around the end of 2012.

As I've used it on and off over the past year, I've observed something particularly fascinating about it: it's one of the first "computer-ey" devices I've yet found which doesn't leave me feeling really exhausted after I use it, something that just about every electronic or "digital" device seems to do (it would seem that I have so-called "EMR sensitivity" (more info at end of post), a condition that virtually no doctor will diagnose but which is a dead ringer for the symptoms that I have. I had no idea there were devices out there I could consistently use without ramifications!).

Sadly, however, this particular PDA is not very practical. It's freakishly delicate... mine sports a redesigned internal hinge mechanism, the result of some quick thinking after the plastic hinge catches shattered shortly after I started using the unit (despite my finding it in practically as-new condition); the LCD/keyboard ribbon cable is supposedly a ticking time bomb, so I don't like opening/closing the lid; and it's utterly unexpandable: besides a CompactFlash slot that's physically incompatible with CFIO cards, it only has a serial port and a non-IrDA-compliant infrared port which refuses to talk to anything else in the house. (And I'm not even going to start on the seemingly endless glitches and (sometimes VERY annoying) bugs I've found in the copy of Symbian OS 1.05 that it runs. :P)

It's been a good proof of concept, its keyboard is excellent, and its BASIC-like OPL onboard programming language is dated but usable, but I need more flexibility (and durability!!).

I'm looking for one or more devices with electromagnetic characteristics that are sufficiently similar enough to the MC218 that I'll be able to use them with the level of consistency that I've grown used to, and which I can use to achieve the following goals:

  • Wi-Fi communicator

    I rather badly need a way to communicate so I can feasibly split up with my family when I and/or they are out and about; currently I have to preagree on somewhere to meet up, which is horribly inefficient. Now, Wi-Fi is roughly similar to cellular communication RF-wise (if you set the output power low enough), but since it would not be good for me to be around anything other than very short bursts of close-range RF energy at the moment, a cell phone would be impossible due to its always-on nature. As an alternative I could actually use, I want to leverage the plethora of free Wi-Fi hotspots to be found in every urban center and configure a device to "wake up", find a free network, connect, check for new messages, disconnect, then turn back off, at around 30-45 minute intervals. So I'm looking for an 802.11abgn-enabled device (-ac isn't necessary; it isn't ubiquitous yet) with an hardware RTC so it can turn itself on from "deep sleep" mode like my MC218 has - the only default state I'll accept keeping it in my pocket long-term - along with a sufficiently configurable/hackable software environment which will let me programmatically examine the available nearby Wi-Fi networks, associate with one, etc, without my needing to remove the device from my pocket.

  • "General usage", self-contained PDA that runs Linux

    Because the MC218 is physically so delicate and I ultimately don't really want to invest that much into it, I am loathe to use its OPL programming language for anything particularly major; the environment itself was open sourced by Symbian several years ago, but the current releases are exclusively for Symbian S60-based devices, so any software I write will become defunct if the MC218 breaks down or I switch to another device. I also do not have much incentive to invest in stabilizing the Linux 2.4 kernels that are available for the unit, due, again, to hardware fragility.
    I'm looking for something that can run reasonably recent versions of Linux (at least 2.6, preferably), so I can develop software on-device which isn't locked to a single platform, and which won't become defunct after hardware failure or succession. (I realize gcc will not be fast. Perhaps I'll get mad with this and get motivated to learn ARM assembly language. :D)

Now for the "OH, that could be a problem." bit. Blum 3

My MC218's seems to be based entirely around two NEC-manufactured ICs, an ARM7TDI/ARM710T (armv4t) CPU clocked at 36.864MHz (I didn't remove the sticker over the CPU before I took a photo of it, so I have no more info about it >.>) along with some kind of companion chip marked "3509-0168-03" / "9913E3002" (the first string returns nonsense listings from parts websites that have no idea what it is, the 2nd returns nada). The other four chips on the board are its 16MB of RAM and 16MB of Flash ROM.

(Click for slightly bigger versions:)

The images above appear to be the only photos of the MC218's motherboard online. They may be reused at will, particularly for archive/hardware info sites; email me for the full-res copies. Smile

Just about everything in it is apparently connected directly to the low-power CPU (which lasts for days on a pair of decent AA batteries!), including the LCD matrix controller, which completely eschews the need for a GPU (even a simple one). I think the fact that it concentrates all functionality into a single low-power CPU is what keeps the level of radiated EMR to a minimum I can handle, and while such restrictions certainly do make suitable alternative device identification a challenge, I believe it can't be impossible to find Angel solution(s). And from a software perspective... don't forget, Linux 0.1 was written on a 386. And UNIX existed before that. A fast CPU and lots of RAM aren't vitally necessary. (My MC218 boots Linux 2.4 in 15 seconds, by the way.)

I've done a relatively in-depth amount of research on the PDAs out there, and while I've found a few devices which come close to meeting my needs, I haven't quite found "it" yet; I don't actually think a PDA is what I'm looking for, but I've no run out of ideas on how else to query Google (mostly lack of knowledge :P).

But here's what I've found thus far, so you don't go over the same ground I have:

  • I page-scraped some relevent-looking sections of AnyTux.org and HPCFactor and sorted their offerings by CPU speed; the slowest Linux-based device on AnyTux is the 66MHz Agenda VR3, which would be awesome to play with but not very practical (kernel 2.4 anybody?). The slowest Linux-compatible devices on the site are the 18.4MHz Psion Teklogix 5, and the Casio Cassiopeia E-10 (49MHz) and E-11 (69MHz), which are all "compatible with restrictions". The slowest devices on HPCFactor are various MobileGear and MobilePro models made by NEC, all clocked at 33MHz. None of these devices list Wi-Fi capability, on these sites or (as I've seen) elsewhere.

  • Searching PDAdb for "CPU speed: 0-40MHz; Cellular radio: None" returns various long-forgotten devices built by Psion (912kHz-36MHz), Oregon Scientific (18MHz), HP (5-16MHz), Geofox (18MHz), NEC (33MHz), Apple (20-25MHz), Philips (36MHz), Compaq, and Casio (both 40MHz).... along with Palm's entire "PalmPilot"-era range of devices running on Dragonball 68000-based CPUs ranging from 25 to 33MHz. I've wanted a Palm device for a while, actually, and incidentally other people with EMR sensitivity have found the Dragonball EZ also used in the AlphaSmart 3000 tolerable long-term (which makes sense, its 25MHz is relatively close to my 36MHz). Now, I figured that Palm PDAs, since they used to be so popular, would be the most likely to support Wi-Fi, but surprisingly (or perhaps not), the only options I managed to turn up (after much hunting!) are a) an in-the-aisle-next-to-the-hens-teeth HandEra 330 with a CompactFlash Wi-Fi card like the Symbol Wireless Networker, or b) a firmware-upgraded Treo 90 with a Wi-Fi SDIO card (which will physically stick out of the top of the unit rather impractically) - whichever I choose, I'm at the mercy of the supplied Wi-Fi configuration applet, which I don't think will take too kindly to my requirements of programmatic remote control. For reference, the "slowest" Palm OS PDA with built-in Wi-Fi is the 123MHz-CPU-based Sony PEG-TH55U, and the slowest Palm OS device with Wi-Fi is the 36MHz AlphaSmart Dana Wireless, but this is a full-sized keyboard which "may" (xD) not fit in my pocket :P.

  • There are quite a few RS232/Wi-Fi converters out there, which are a possibility to Wi-Fi-enable a PDA with a serial port, but most incorporate a triple-digit microcontroller into the device for configuration and management (and some of the CPUs run Linux, heh). The "slowest" option I've found is the Grid Connect xPico, which integrates an ARM Cortex M3; these apparently run at 80MHz. What I'm really looking for is a Wi-Fi module which can completely switch off, either on-module, or because the device I've attached it to can somehow switch it off. This would actually be extremely practical from a Wi-Fi-"scriptability" perspective, but I would be limited to the maximum throughput of the PDA I was using it on, which is typically 115200bps; don't forget that the "b" in "bps" == bits, not bytes... and so "115200" actually means "14.4kbps". Ouch. That's a quarter the speed of 56k dialup. I could use that for IRC, but definitely not general Web browsing!!1 o.o :S

  • The TL-MR10U, -11U and -13U are a series of 3G-dongle<->Wi-Fi "converters" made by TP-LINK, which happen to work really really well with OpenWRT, with which they can then be more accurately thought of as an "802.11abgn Wi-Fi, 100Mbit Ethernet, USB 2.0, GPIO and RS232 concentrator with 32MB of RAM and a rechargeable battery that will fit in your pocket". You can do just about anything with them (the -13U's battery is actually just over 10Ah, so it even doubles as a portable USB battery pack); OpenWRT gives you the very latest kernel and a userspace with a package library of prebuilt binary software that installs in moments. FTW... if you like 400MHz CPUs (!!!). They're pretty awesome considering what they integrate, but since these don't have screens, it is difficult to intuit what their practicality would be. I could hook one up to a USB IrDA dongle and use eg a Palm device as a display/input device, but this would be somewhat finicky.

  • The iMOVIO iKIT, Ben NanoNote, Zipit Wireless Messenger (both the original and the Z2), Sharp Zaurus, HP Jornada, and Unication Magpie PDA devices all either ship with or can be made to run Linux and have built-in Wi-Fi and a keyboard, but run at 200, 300 or 400MHz, which Simply Won't Work(TM) - the only remote possibilies would be the Magpie, which doesn't seem to exist on the market anywhere (all I can find are some old reviews on it); or the original, not-particularly-fancy-looking Zipit (which is also 200MHz), but this only incorporates *8MB of Flash ROM* (!!), making configuration a definite exercise in optimization (and throwing any ideas of onboard software development out the window).

Ideas and feedback highly appreciated! I'm posting this from an 800MHz AMD Duron which I can kind of deal with for the time being (I used to use a 2.6GHz Pentium 4 several years ago but it left me insanely angry all the time; this PC is (obviously) slower, but I'm actually less impatient with it). Unfortunately, I'm pretty sure I'll have to have another "extended break" at some point; I just hope my next one isn't like the one I had to have between 2008 and 2013, where I couldn't use anything remotely "technically advanced" for more than a few minutes. I've found various natural/alternative therapies have helped me somewhat since then so hopefully this doesn't happen, but I'm certainly not "stable" yet, and this is why I'm asking these questions.

Thanks very much in advance Smile


"Appendix": Answers to some responses I've previously received when talking about this:

  • "Shield a bigger device." I specifically want something that can fit in my pocket or is at least small, not just due to EMR sensitivity, but because this would be more practical. Also see the point below.
  • "Just shield it..." Fairly speaking, I honestly can't say I've actually tried this, but based on what I've read thus far I don't currently believe shielding would work, for three reasons:
    1. I can't possibly shield everything, and I've found myself particularly sensitive to things like train network electrical booster substations in the past, which are exceptionally hard to shield :P... what I'm *really* interested in is figuring out why *I'm* sensitive, and working on *me*.
    2. I don't recall what book I read this in, but I remember reading somewhere of a person expressing their bafflement at how RF was able to travel through most metals. No idea if this is true.
    3. Consider this theorization. If you put a person in a giant faraday cage, then hit said cage with lightning, the person will be okay as long as they don't touch the cage because they are completely isolated and the cage is a "perfect barrier". However, if you push a large metal rod into an empty faraday cage and hit the rod with lightning, the lightning will "permeate" the cage through the rod and splay out in all directions inside. Now, if you left the rod in place but crammed the lightning generator inside the cage, I would imagine the rod would carry the lightning outside the case and it would go everywhere (meep :P). Now, if you switched the lightning for EMI... and switched the metal rod for electrical cable passing through holes in a faraday enclosure... what happens next? I figure the answer is "the EMR leaves the case". And if the EMR is not appropriately shielded it will leak. Now explain how to EMR-shield, say, a screen. Sad
  • "It's all in your head." Close. It's actually in my nervous system, which is connected to my head, and thus, when my nerves start flipping out, my head subsequently feels very very weird (a combination of REALLY tired, spaced out, and irritated).
  • "You're emotionally imbalanced, or seeking attention." No. I'm a geek at heart. I would very much like to use the computer indefinitely without issue. I would also like to take the stress of being unable to hold down a job off my family (think: what job will never, ever, ever require I use a piece of electronics? I can't guarantee from a business/insurance/OH&S perspective that I can keep a job unless this condition is met). No sir, this is causing so many problems in my lifestyle I'd have to be psychopathic to be faking and/or enjoying it.
  • "You're paranoid." True! EMR sensitivity destabilizes the nervous system. Imagine if you were at the mercy of a condition which randomly, inconsistently causes you to unpredictably become incredibly distressed to a random extent that you have no control over, and cannot reverse or mentally ignore. That's what EMR sensitivity is at its core, and everyone flips out differently (I'm still defragmenting the physiological "split" that resulted from my brain trying to sort out my anxious reactions to EMR vs. my continuing interest in computers). This is why people with EMR sensitivity or multiple chemical sensitivity (something I don't think I have but which seems to be commonly related) have a very intense, nervous disposition. Personally, I'm less sensitive than I used to be, but as I said above, I'm not yet stable by any means.
  • "If you can handle Wi-Fi, you don't have any issues." EMR sensitivity isn't black-and-white like that. There are (seemingly infinite) shades of grey. In my case, I can't handle Wi-Fi transception for more than a few minutes. Another person might instantly have a grand mal seizure if exposed to this at close range, or yet others might be fine leaving their cellphone induction charging on their bedside table every night, associated with their Wi-Fi AP, locked to umpteen GPS satellites because they forgot to close some GPS tracking app, and tethered to their Bluetooth speakers to play music overnight.

"Appendix 2": Some of the more interesting/notable experiences I've had using (or not using :P) electronic devices

  • My Samsung SA58700X08-based iRiver S10 continues to make me feel really weird when I listen to it and quite angry afterwards, despite the fact that I listen to music out of approximately 12 VERY moderately amplified speakers when on the computer. My consternation with 200MHz devices stems from my experience with this unit - although I wonder, could it specifically be the DSP (or furthermore, the way it was programmed? o.o)?
  • My Casio CFX9850GB+ scientific calculator uses a 4MHz ZX933 CPU and a tri-color (blue/orange/green) 3-layer LCD. I **seem** (!!) to be okay with it at the moment, but when I used it a few months ago I was only able to use it for a few days or my brain would start to become so spaced out I would not be capable of really engaging in anything. I remember going on a bus ride home after having used it for a while and feeling like if I was going to talk, I'd say something inappropriate - not "bad attitude" inappropriate, but self-conscious/"out of place" inappropriate. I've since learned that the front of the brain controls speech and the appropriateness of our conversation, based on context; ie, it's on overdrive at formal functions, but reasonably relaxed around friends and family. Thus this shows that my communications with this area of the brain was somehow impacted. I also found myself visually perceiving some kind of "flopping" sensation in front of my eyes after using the calculator for a time; I didn't "see" an object as such, but rather percieved it as a visual sensation, that something was physically up with my eyes. I'm using an LCD screen at the moment though, albeit with a CRT screen glare protector on the front (which looks hilarious but means my eyes don't feel like they've swallowed a hive of bees after I've used the computer for a while).
  • I had a rather wonderful, highly enlightening experience following my recipt of a PlayStation/2, which I would prefer not to have again. (This was what caused me to learn that I was sensitive to EMR.)
  • I found a (presumably "dead") tollway E-Tag in an op-shop (the same one as where I found my MC218! ^^) and promptly grabbed it to find out how it worked. Oh. Boring PCB. Huh, a battery? Didn't expect that. Okay then... now I know. *tosses into corner* *forget about E-Tag completely, a couple of days pass*
    *start getting obsessively distressed about tiny things* (<-- my no. #1 symptom >.>)
    *become depressed*
    *thinking becomes foggy can't think clearly* (<-- this is where I start going "ookay, what did I do wrong..." - usually the answer is "went on the computer for too long", but I wasn't using the computer at this point)
    *remember E-Tag!!1*
    *open back up* *rapidly maneuveur (:P) battery off PCB* *sensation like burden being lifted from shoulders, mind instantly clearing* "OOH. I didn't know I was so stressed!!!11!"
    *all issues mysteriously go away over 24-hour period*
    That was NOT an unconscious emotional link or anything psy{i,ch}ological like that. Honestly and fairly speaking, if someone hooked up a random timer to sequentially switch this tag on and off over a period of days (I still have it, neutered :P), I (and my family >_>) would know when it was on and when it was off with practically 100% consistency.

Last seen: 3 months 1 week ago
Joined: Dec 19 2003 - 18:53
Re: Pocketable ULTRA-low-powered device with Linux and/or Wi-Fi

I have a solution for your telecom needs. Get an iPod Touch, and a MiFi WiFi (cellularly connected WiFi) setup. Get a Skype account and use it over this hardware. If you get the TruConnect brand of portable WiFi device, it has a removable battery, so it won't give off any EMF when the battery is out. Turn off or put to sleep the iPod Touch when not in use. Also for security reasons, you can get EMF blocking bags for these small devices.

As far as the programming, I have no idea if a flavor of LINUX is available in the iOS realm, but there are some good programming languages/suites for it.

I think it's possible that you are sensitive to looking at actively backlit screens. Most of them are backlit with florescent tubes, which trouble many people. Another alternative for your out-and-about PDA needs would be the Kindle Paperwhite, which looks great and isn't back lit at all.

Last seen: 4 years 6 months ago
Joined: Nov 21 2013 - 20:47
Re: Pocketable ULTRA-low-powered device with Linux and/or Wi-Fi

Hi! Thanks for your reply, and thanks for taking the time to read my OP Smile it's a bit long (but my most condensed version yet) Blum 3

First things first, something completely off-topic: CTRL+R in web browsers does not "redo" an undone change in a text field. Smile (I've disabled CTRL+R systemwide for the time being, although I'm starting to realize where I used it. Grr...)

So, take two. Blum 3

Unfortunately, you had me at "iPod Touch". The first ever iPod (think 2001, click wheel, revolution, etc =P) used a dual-core 80MHz CPU, so even that would sit near the bottom of my list if it were Wi-Fi-capable. Current iPod Touch models use a dual-core 1GHz SoC which integrates a 16-core 200MHz GPU (MEEP). My answer to this: "Nobody here even owns anything running at 1GHz in the entire house!" Blum 3
The first iTouch used a 400MHz CPU, by the way, but I'm highly dubious of PDAs running at half that speed, and all iTouches integrate GPUs of some form or another to support Apple's animation habit, so this line of thinking is simply impossible. :/

A cellular Wi-Fi modem with removeable batteries sounds like an interesting idea, but I think there was a bit of a misunderstanding or misconception at some point: removing the battery from the Wi-Fi/cellular modem is not going to kill the Wi-Fi radio in the device talking to it. You've got the idea half right; it'd be the Wi-Fi module in the iTouch I'd be wanting to unplug Blum 3
Secondly, the urban centers, shopping malls etc that I visit are full of free Wi-Fi hotspots; I don't yet have any devices which can "see" or use these hotspots (hence this post!! Biggrin :bigsmile:) but I can see plenty of signs declaring their existence... so in the face of a freely available zero-cost option, I'd only be falling back to cellular if Wi-Fi was an utter logistical impossiblity from an EMR perspective (and I don't think it is, as detailed in some of the ideas in my OP).
Furthermore, a periodically-polled wireless communication system would be impossible with such a configuration: I need a device which can switch itself on, check for new messages, then switch itself back into deep sleep, every 30-45 mins or so.
Finally, I only want one wireless medium to deal with - Wi-Fi or cellular - in order to limit the amount of close-range radiated RF.

Canonically, early BlackBerry models used ~80MHz CPUs and EPOC R6-based Nokia Communicators (the cellular-enabled devices that were the generation after my MC218) used 54MHz CPUs, so these would be likelier possibilities for me if I was going to go down the route you're talking about, but I really really want to see if Wi-Fi can work first.

To answer your question about backlit screens, the reason that I posted what I did about the CFX9850GB+ was that its screen was entirely reflective, although I should have probably clarified that.

And I've had "e-ink display connected to ~30MHz CPU" in my head almost every second day Smile but I don't think it exists Cray 2

If there are any other parts of my OP or this message that were confusing, please do let me know, so I can improve them - thanks Smile


eeun's picture
Last seen: 2 weeks 1 day ago
Joined: Dec 19 2003 - 17:34
Re: Pocketable ULTRA-low-powered device with Linux and/or Wi-Fi

Have you considered using an Android phone or tablet sans sim card for wi-fi only communication?

You could set up a cron job on the phone to enable/disable the wi-fi at regular intervals; there's an application in the Google Play store that will do exactly that without any command line fuss or rooting (I have no idea if such options are available on the iOS side).

I have a cheap Huawei phone, and the battery lasts for days providing I have wi-fi turned off. You could always power-off the device at other times as well if needed (ie at night, or whenever everyone's at home).

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