Comments on: Dual core… Arduino?

By: dro kulix

dro kulix — Mon, 14 Apr 2008 17:10:25 +0000

Isn’t a 74HC595 shift register, like, a quarter?

Concurrent firmware (on something other than the Propeller) would be interesting, though. :-)

By: Ric Johnson

Ric Johnson — Mon, 14 Apr 2008 16:07:21 +0000

What about an 8-to-1 multiplexer chip? $1?

By: mem

mem — Sun, 13 Apr 2008 11:10:16 +0000

the only real hack in this is the semi clever name.

By: Takato

Takato — Sun, 13 Apr 2008 07:30:59 +0000

He needs to get a truckload of arduinos (1024 maybe?) and build the computer with the most processers that can still fit in a small bathroom.

By: DarkLightConnection

DarkLightConnection — Sun, 13 Apr 2008 03:13:17 +0000

Useful or not, “dual-core arduino” sounds very macho

By: chupa

chupa — Sun, 13 Apr 2008 01:15:15 +0000

why?

By: Lupin

Lupin — Sun, 13 Apr 2008 00:39:51 +0000

I am surprised this is considered a hack…

This is like connecting two lamps in parallel and being surprised that both glow.

By: pc486

pc486 — Sat, 12 Apr 2008 09:03:13 +0000

There are plenty of i2c I/O expanders out there that are much cheaper than a full ATMega168. Not nearly as cool though :p.

By: morcheeba

morcheeba — Sat, 12 Apr 2008 08:56:35 +0000

He wired the chips in parallel - this doesn't seem to be a good idea. Resonators are usually driven by a not gate - one pin is an input, the other is an output. It's wired so that the two outputs are driving each other -- bad practice! This will waste energy and stress the parts. It'll also create a lot of electrical noise as the power supply is repeatedly asked to supply the short circuit current every oscillation.

The better solution is a master/slave setup. One device will control the oscillator (connect XTAL1 and XTAL2 as usual) - this is the master. The other device is set up in "external oscillator" mode, with its input driven from the first. I looked at the spec sheet quickly, and it looks like XTAL2 is the output and XTAL1 is the input - this means you should connect XTAL2 of the master to XTAL1 of the slave. (you can verify this with an oscilliscope - the output waveform should be the squarer one)
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On another note, I've thought it would be fun to take a 10 x 10 array of these tiny 100 MHz processors and make a 10GHz-equivalent computer on a 4x4" pc board:

http://www.silabs.com/public/documents/tpub_doc/dshort/microcontrollers/small_form_factor/en/c8051f365_short.pdf

but, with limited communication, it could only run certain apps well.