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I'd like more interrupt pins. Is there a chip that does the opposite of the 74154 - i.e. when one of 16 pins goes low (or high) it gives a 4-bit address of the device that threw the interrupt?
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Daniel
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The 74HC147 will do that.. but it's a priority encoder that outputs the highest interrupt, so you will miss interrupts from lower-priority pins. I think there's a CMOS version too: 40147.
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Thank you, Daniel - that's just what I was looking for.

Given the possibility of missing lower priority interrupts, maybe it would be better to have the interrupting device throw a latch which in turn throws the interrupt. Then I just poll the latches to find out who triggered the interrupt. But that sounds a little slow, doesn't it? Not much better than simply polling the devices one by one in a loop and not using interrupts at all. Or I could use the 74HC147 together with latches to save any lower-priority interrupts. Or maybe the Arduino isn't the best choice for a multiple interrupt real-time project, namely a MIDI drum trigger/controller.

At any rate, thanks again for your help.
Jesse
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A follow-up to this: it seems that the ATMega168 is the solution to this. The I/O pins on this chip can be used as external interrupts, giving you a total of 26, without priority encoding. This, together with the increased flash ram, makes the 168 a very useful part. I'm joining the apparently long list of people waiting for the Bluetooth Arduino.
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quick updates

the boards are manufactured and ready for shipment
we'll test the bootloader a bit more then
the manufacturer will start shipping starting from the customers who have pre-ordered

massimo
« Last Edit: January 13, 2007, 10:36:43 am by admin » Logged

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Where does one go to order one? There doesn't seem to be much about it on the regular arduino web site. No specs, no price.
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Daniel
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Quote
Where does one go to order one? There doesn't seem to be much about it on the regular arduino web site. No specs, no price.

I think this process take a little time... as you can imagine, a group of unpaid developers does not work the same way as a big Corporation!

But, of course, the unpaid developers build a better product!!!
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have a look here for a  preview
http://tinker.it/now/2007/01/13/the-arduino-bluetooth-board/

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Seems like the Atmega 168 is soldered in place and cannot be removed anymore.
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Daniel
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hey Massimo,

the board looks really good. I am wondering: what kind of connector is that for the DC power? Is it something that one can get plugs for  in North America?

D
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he's looking at you, kiddy...
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It is a industrial connector, frequently used by tinker.it. Remember the picture is still a prototype. I suspect that the production run will have the far inferiour consumer connector again. (Ohh how i hate that plug. try to buy one without the original at hand...)
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