On Fri, Sep 2, 2016 at 12:37 PM, Joseph Honold mozzwald@gmail.com wrote:
On 09/02/2016 09:58 AM, Luke Kenneth Casson Leighton wrote:
well, do add the research that you've done to http://rhombus-tech.net/community_ideas/clamshell_microlaptop/
that's what the wiki is there for. at the same time can you please add mention of the SEW291 3G module, and that it's $12 in low volume, and that it uses an MSM6260 chipset.
Will do. Really, I'm just trying to keep the *conversation* going and get more input from others.
also, whilst initially it looks really great to add a $1 TI TCA8418 or other I2C chip, you soon find that you need another $1 chip, then another $1 ADC/DAC chip, then another $1 chip, and pretty soon it's like "hang on a minute this is f*****g stupid, that's $5 worth of ICs to do the same job as a $1.50 STM32F072!"
Good point. It all depends on what features get implemented in the handheld. TCA8418 combined with STMPE811 touch controller/gpio expander seems like a possible low cost option. Both have linux drivers so no need for custom firmware.
also bear in mind that from experience with the HTC Universal reverse-engineering doing clamshell phone / pdas is f****** complicated. beyond *any* shadow of doubt they are by far and above way more complex in terms of I/O than laptops, or even intel desktop PCs.
Yeah, the mechanics of the hinge and getting cables from top to bottom would be a pain. I'm leaning towards the candybar form factor to keep it less complicated.
My list of wanted features: QWERTY Keypad with backlight Wifi Cellular (optional) 640x480 or higher resolution LCD Touchscreen (resistive) Ambient Light Sensor (for backlight dimming) USB Audio (headphone jack, internal mic, ear speaker for phone, loudspeaker) USB Hub [wifi, audio, cellular, external host port(s)] Camera (optional, USB) Micro SD Slot
You might be able to get a good head start by taking the GTA04 schematics (basis of Neo900) and looking at modifying them to accept an EOMA-68 computer card rather than having an onboard processor.
The GTA04 is a fairly mature schematic, the latest revision GTA04A5 is going through the final stages before a production run.