[Arm-netbook] IC for analog and digital buttons (EOMA-68)

[Luke Kenneth Casson Leighton]

On Wed, Aug 6, 2014 at 9:57 AM, krasi gichev <krasimirr at gmail.com> wrote:
> I suspect that we are not looking at the complete picture here. Don't you
> have some more sensors to add on the I2C? Like accelerometer, magnetometer,
> maybe light sensor (for auto brigthness) and so on? Maybe battery
> monitoring?
> I see that you are discussing about using I/O expanders and ADC chips. Not
> to say that IN YOUR CASE you have to use microcontroller - just to show some
> points that could help you to take the right decision. .
> Using I/O expander means that you need several chips - at least two. This
> will take some board space and pin connections. Don't forget that beside I2C
> lines (SDA, SCL) you might need some (maybe one, maybe two) interrupt lines.

 i've added 2 EINTs to the specification for exactly this purpose.

> (ROM) bootloader with support for UART, SPI, I2C and so on. I would propose
> STM32 for example (it is quite well supported by open source tools and code
> base).

 this is the original that i used in one of the early prototype tablet
pcbs, it's very good, however the low-cost ones (STM32F103) don't do
USB, you have to go to the $5 variants to get USB.

 i think, manuel, if you draw out (even sketch) the full connectivity
required then we can help evaluate.

l.