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Message-ID: <48ECA101.8010604@billgatliff.com> Date: Wed, 08 Oct 2008 07:01:05 -0500 From: Bill Gatliff <bgat@...lgatliff.com> To: Jon Smirl <jonsmirl@...il.com> CC: ARM Linux Mailing List <linux-arm-kernel@...ts.arm.linux.org.uk>, lkml <linux-kernel@...r.kernel.org> Subject: Re: Toggling GPIO at 38Khz Jon Smirl wrote: > > Are there other techniques for generating pulse trains in the 36-56Khz > range on a simple GPIO pin? > Yes. Use the GPIO pin to enable the output of an external circuit. Or, hope that the GPIO pin in question is multiplexed with a timer/counter or PWM peripheral. But somehow, I don't think either answer is what you were looking for. :) 36 KHz bit-banging is a reach for any processor running Linux, methinks. Maybe you could launch an FIQ (assuming ARM) and then do the bit-bang as a burst in there, so that you would have more control over the timing. But that kind of code isn't going to play well with the rest of the kernel... If the hardware design isn't set, you might want to consider using that GPIO line as a quasi-SPI link to a small, AVR-type microcontroller that does the bit-banging on your behalf. Long-term, that's going to be a more reliable and flexible solution I think. b.g. -- Bill Gatliff bgat@...lgatliff.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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