On 14/08/11 17:20, Phil Endecott wrote: [...] >> other interfaces including some GPIO pins > > That is actually something that is annoyingly missing from the iMX53 board - a > handful of signals on a sane connector that could be connected to switches and > LEDs. In the past, I have resorted to using modem control signals for this > sort of thing. The iMX53 has I2C, SSI and SPI out on the expansion connector; it *ought* to be possible to hook up a GPIO-capable device to one of these buses. An uninformed web search shows up the PCA9698, which speaks I2C and claims to provide 40 GPIO pins with a total loading of 1A. I've never used any of this minimal buses, though, and so don't know whether this kind of thing is feasible in real life; I suspect it would depend a lot on whether the iMX53 has a real UART or is just bit-banging pins. And what else is on the bus. I2C, SSI and SPI seem to be such an awesome idea for simply adding homebrew expansion devices that the fact that nobody appears to be using them for such makes me slightly wary of them... -- ┌─── ｄｇ＠ｃｏｗｌａｒｋ．ｃｏｍ ───── http://www.cowlark.com ───── │ │ "I have a mind like a steel trap. It's rusty and full of dead mice." │ --- Anonymous, on rasfc
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