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

krasi gichev krasimirr at gmail.com
Thu Aug 7 15:00:51 BST 2014

Firmware update of newer STM32s could be done over USB too - you don't need
separate UART for this. Just wire BOOT pin (pins) to GPIO(s) from EOMA to
allow entering firmware update mode (DFU over USB).
64pin seems an overkill - there a lot of other package options, e.g. 48pin
QFN, not to mention the BGA variants. Also, F103 is quite old one, probably
the price might be good, but I would recommend some of newer ones
(Cortex-M0 even) - look at F0, F2, F3 series. A good option could be this:
STM32F071CB, the price goes below $2.50 for 100pcs, and it seems to have
all you need -

SiLabs "Precision 32" are also nice ones - very well balanced peripherals
and packages (e.g. QFN40, SiM3U154), built in regulator from 5V (if
needed). But the price is higher.

2014-08-07 12:07 GMT+03:00 Miguel Garcia <gacuest at gmail.com>:

> 2014-08-07 10:13 GMT+02:00 Luke Kenneth Casson Leighton <lkcl at lkcl.net>:
> >  blegh - and you need 2 of them _and_ 2 analog ICs as well. that's
> > starting to make the STM32F103 (64-pin variant) look attractive.  and
> > i know you can get that at around the $2.50 mark in 10k volumes.
> >
> >  *sigh* ok do you really need that USB Flash thing?  because of a) the
> > cost (at least $4.50) b) the number of ICs (4) it's starting to tip in
> > favour of the STM32F again, i get the feeling you'd be better off
> > wiring up the STM32F as a USB 1.1 device.  you'll also need to wire up
> > the UART to the EOMA68 interface and a couple of other pins to put it
> > into "firmware upload" mode, but that's ok.
> >
> >  the advantage there is that i have some GPL'd KiCAD designs with
> > STM32F already in them (or have found some out there when i last
> > checked).
> Yes, the USB flash drive can be removed.
> I think Daniel also prefers a microcontroller.
> 2014-08-06 14:18 GMT+02:00 Luke Kenneth Casson Leighton <lkcl at lkcl.net>:
> >  * one GPIO IC IN pin is needed for MicroSD "detect"
> >  * digital GPIO IC OUT pin needed for power-up of LCD
> >  * accelerometer IRQ goes to digital GPIO IC IN
> >  * digital GPIO IC IN pin connects to IRQ-OUT of AXP209
> >  * digital GPIO IC IN pin connects to Headphone-detect (in case you
> > want to alter volume on headphone-out)
> So, do we connect all this to STM32F? Or do we have to add the STM32F
> and the digital GPIO IC?
> Thanks.
> _______________________________________________
> arm-netbook mailing list arm-netbook at lists.phcomp.co.uk
> http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook
> Send large attachments to arm-netbook at files.phcomp.co.uk
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.phcomp.co.uk/pipermail/arm-netbook/attachments/20140807/dbc23722/attachment-0001.html>

More information about the arm-netbook mailing list