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

[Luke Kenneth Casson Leighton]

On Fri, Aug 8, 2014 at 1:04 PM, Miguel Garcia <gacuest at gmail.com> wrote:
> 2014-08-08 10:33 GMT+02:00 Daniel Iglesias <daniel.iglesias at gmail.com>:
>> Is there a smaller one in the same family we could use? Such as the
>> STM32F072'C' or 'R', which have 37 and 51 GPIOs respectively and nearly the
>> same number of ADCs as the bigger 'V' variant. I suppose it'd make PCB
>> design/routing easier, since the number of pins and the dimensions of the IC
>> roughly double between the 'C' and the non-BGA 'V' variants. I don't know if
>> there are any disadvantages to using the smaller ones though.
>
> And they are cheaper.
>
> STM32F072CB: http://www.stmicroelectronics.com.cn/web/catalog/mmc/FM141/SC1169/SS1574/LN1823/PF259606?s_searchtype=partnumber#
>
> STM32F072RB: http://www.stmicroelectronics.com.cn/web/catalog/mmc/FM141/SC1169/SS1574/LN1823/PF259605?s_searchtype=partnumber#
>
> A stupid question. STM32F072 has USB 2.0 connectivity. Does
> connectivity can also be USB 1.1?

 very good point.  and it's not a stupid question at all, because if
you look e.g. at the OMAP35xx series they *only* support full-speed
(480mbit/sec) USB, they *do not* support slower speeds so you always
had to connect a full-speed USB Hub to them if you wanted to connect
even a single USB 1.1 device.

> I say this because the second USB of
> EOMA may be USB 1.1 and will not always be USB 2.0.

 well, you could just make sure that you go through the hub... which
you are planning anyway, then it is the hub's problem to do the
buffering and packet forwarding.

 so i *believe* it's fine...

 you're planning to pass the "main" USB (the one that can be up to USB
3.0) directly through to a USB Host connector aren't you.

l.