Comments on: Centipede shield design contest

By: Drone

Drone — Tue, 10 Nov 2009 06:08:28 +0000

“which allows the Arduino (or any other microcontroller with I2C) to add 64 digital I/O pins”

Not likely, this “shield” has the stupid Arduino gap that won’t fit anything that has standard 0.1″ spacing.

By: taylor

taylor — Mon, 09 Nov 2009 20:16:10 +0000

@shitehawk
No f’ing idea what you said. :)
-Taylor

By: shitehawk

shitehawk — Mon, 09 Nov 2009 19:48:53 +0000

I know this is not the right place for this but I figured someone might know what i’m on about here. I am wondering about an easy way to get alpha channels on modern serial controlled pll cb’s such as the BU2630F E-2 without reprogramming the eprom. What would be needed to make a parallel breakout board that I could wire to the 3 pll lines da ce cl so I could pull high or low the 10khz pin like the old pll02a mods?

By: chango

chango — Mon, 09 Nov 2009 15:40:08 +0000

@mj:

If you need to monitor a lot of temperatures you might want to look at the Maxim-Dallas 1-wire remote temp sensors like the DS1822-PAR. You can multi-drop them on just two wires. They’re kind of expensive compared to a handful of thermistors or insert-your-favorite-temp-sense-diode-junction-here, but they’re factory calibrated and easy to wire.

By: rasz

rasz — Mon, 09 Nov 2009 10:29:59 +0000

I can be biased as I can always jump into subway and have 200 shops to chose from in 10 minutes, but Microchip being a pain when it comes to availability is not something I imagined in my head :). For example Dave from EEVblog said few times that its the same (or worse) in Australia where they cant even get bulk orders in reasonable time. If Microchip ignores bulk clients something is very wrong.

By: therian

therian — Mon, 09 Nov 2009 10:11:11 +0000

@rasz
“Ok my bad. They are available if you are willing to order one IC for $1 and pay $5 for postage.”

like there is other option for any other component. If you have electronic parts supplier locally you extremely lucky. For most US there is only RatShack and they already add extra 5 for any part :(

By: mj

mj — Mon, 09 Nov 2009 09:33:58 +0000

It would be more interesting to use the I2C and a breakout to have massive amounts of analogue inputs for sensor arrays. They mention a muxxer that does this in the comments.

64 analogue inputs would be nice for temperature array monitoring.

By: rasz

rasz — Mon, 09 Nov 2009 07:46:22 +0000

im sure there is a lib for it to simplify usage. You wont have to bitbang i2c or anything like that :)

By: Borgar

Borgar — Mon, 09 Nov 2009 06:39:03 +0000

Oops, im mean “NOT too experienced”

By: Borgar

Borgar — Mon, 09 Nov 2009 06:37:45 +0000

i find this interesting, i’m too experienced with the code involved, so if i ever need that many i/o’s i’ll buy an arduino mega

call me primitive but its alot simpler

By: rasz

rasz — Mon, 09 Nov 2009 01:30:59 +0000

Ok my bad. They are available if you are willing to order one IC for $1 and pay $5 for postage.

I was thinking “in a brick and mortar shop” … or in Europe. Yes, we still have those.
I love Microchip when it comes to samples and occasional PIC 16, but trying to buy something else from them is a mayor PITA.

Crap, we have a big Electronics market in Warsaw (open air + surrounding shops), probably biggest in Europe.
http://maps.google.pl/maps/mm?client=opera&q=20.93889,52.285816&oe=utf-8&ie=UTF8&hl=en&t=h&ll=52.285609,20.938721&spn=0.001596,0.00327&z=19

Thats 200 Electronics shops one next to the other big. Thats like a mini version of Shenzhen electronic market (size of one SEG floor). You wont find anything from Microchip other than PICs there.

By: macegr

macegr — Mon, 09 Nov 2009 00:43:59 +0000

Yeah the heart of this project is just how cool the MCP23017 is. Cheap, gives you 16 I/O that are as capable as normal uC I/O. The Centipede Shield is just a handy way to get four of them on a small board. It seems so useful, but I couldn’t think of any project that needed 64 I/O, so I had the idea for the contest.

By: rasz

rasz — Sun, 08 Nov 2009 22:45:06 +0000

Ok my bad. They are available if you are willing to order one IC for $1 and pay $5 for postage.

Crap, we have a big Electronics market in Warsaw, probably biggest in Europe.
http://www.wolumen.com.pl/index.php?page=infogielda&sh=0
http://maps.google.pl/maps/mm?client=opera&q=20.93889,52.285816&oe=utf-8&ie=UTF8&hl=en&ll=52.285422,20.939051&spn=0.006386,0.013078&t=h&z=17

Thats 200 Electronics shops (tents :P) one next to the other big. Thats like a mini version of Shenzhen electronic market (size of one SEG floor). You wont find anything from Microchip other than PICs there.

By: jproach

jproach — Sun, 08 Nov 2009 22:23:16 +0000

http://www.findchips.com/avail?part=mcp23017

Looks widely available to me.

Advantages of the mcp over the pcf:
Voltage range is wider, max i2c clock speed faster, configurable interrupt source and pins, configurable pull-up, available in DIP, and price is lower.

By: matt

matt — Sun, 08 Nov 2009 21:48:20 +0000

@rasz: The mcp23027 is available at mouser for $1.14 single quantity with parts in stock.