[Arm-netbook] ZeroPhone

[Luke Kenneth Casson Leighton]

---
crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68


On Fri, Apr 14, 2017 at 6:00 AM, Louis Pearson
<desttinghimgame at gmail.com> wrote:
> https://hackaday.io/project/19035-zerophone-a-raspberry-pi-smartphone

 totally coool.  uses a SIM800 quad-band GSM module.  really good choice.

> Not exactly a netbook, but this looks like an interesting project. How much
> work would
> it take to create something like this using EOMA68? I know I would be
> interested in a
> device like that.

yeah you and me both - the thing is: the cards are 5mm x 86 x 55mm (or
thereabouts) which means that by the time you've created a stack of
all the components (screen, battery, lcd, keypad or touchpanel) you're
looking at something like 17 to 20mm in height.

 so that's why i wanted to do something using EOMA50 (reuse of
CompactFlash) as the Cards would be 3mm x 43 x 33 (or thereabouts) -
that means having to source a suitable SoC.  i found one about 18
months ago - the Ingenic M150.... only ARGH for Ingenic to STOP
SELLING IT, damnit.

 the M150 was perfect as it contained its own on-board SDRAM (128mb of
DDR2), and the developer board reference design was something like 25
x 20mm.

 anyway i am still on the lookout for similar SoCs, and have created this page:
 http://rhombus-tech.net/community_ideas/hybrid_phone/

 the idea there is to use an LCD that has *dual* control interfaces:
SPI *AND* RGB/TTL.  the SPI interface would be wired directly to an EC
(e.g. an STM32F072 which i really like) which would have the ABSOLUTE
most basic of interfaces and functionality ("dumbphone" mode), and
also take care of the audio, but when the EOMA50 Card was plugged in
the LCD would be switched over to RGB/TTL mode and you'd have a
"smart" phone.

 it'd be quite complicated hardware - phones always are - but a lot of
fun.  if you're not familiar with how INSANELY complex phone hardware
is, have a look at the reverse-engineering effort i was involved in,
back around 2003, with the HTC Universal.  the AKAI 4641 audio IC had
SEVEN separate audio paths.  i had no idea that there was actually
*yet another* audio multiplexing IC (it hadn't been identified at the
time) from TI...

 https://forum.xda-developers.com/wiki/index.php?title=HTC_Universal/Research&ajax=0

l.