[Arm-netbook] Future case idea: subnotebook/PDA with QWERTY keyboard

[Joseph Honold]

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

On 09/02/2016 11:13 AM, Sam Pablo Kuper wrote:
> Any microphones or speakers (or cameras for that matter), if present,
> should have hardware switches so that they can be kept disconnected when
> not in use, to avoid eavesdropping, key-logging, etc.

We can use MOSFETs (SY6280 or other) as switches to disable power to each device independently