On Thu, Aug 7, 2014 at 8:51 AM, Miguel Garcia gacuest@gmail.com wrote:
2014-08-07 8:57 GMT+02:00 Luke Kenneth Casson Leighton lkcl@lkcl.net:
...except do try to find one that's a bit less than $0.95 in volume!! http://www.futureelectronics.com/en/technologies/semiconductors/comm-product...
If SPI is better, MCP23S17 is an interesting alternative.
faster for sure. I2C tops out safely at 4mhz. SPI i believe can do 25mhz.
$1.00 en volume:
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).
l.