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4921  Forum 2005-2010 (read only) / Development / Re: does anyone knows some companies that uses arduino on: June 10, 2010, 08:46:14 pm
they are still small scale.
There's nothing wrong with small scale.  If you're going to get particular about your definition of "real company", be sure to state the definition you want to use.  I'm pretty sure that EMSL made more money in FY2009 than Atmel, for example (pretty easy, since Atmel lost $124E6...)

As soon as a product goes larger scale, companies aren't bothered about making it easy to modify and code as the general public don't care and it wouldn't affect them
Maybe.  At the moment, it looks more and more like companies aren't bothered about making things NOT easy to modify/code either.  Look at the huge number of linux based routers, picture frames, gps units, and etc that people are hacking to their own purposes.
4922  Forum 2005-2010 (read only) / Development / Re: does anyone knows some companies that uses arduino on: June 10, 2010, 04:53:36 pm
Evil Mad Scientist Labs ( has several electronics kits using ATmega chips that have been made "compatible with the arduino environment."  I don't know if that's the sort of company or product(s) that you had in mind, but I think it's a fine demonstration of one way to "incorporate" Arduino into "real products."
4923  Forum 2005-2010 (read only) / Development / Re: Looking for info on running at 20mHz on: May 06, 2010, 11:33:22 pm
If you add the following to your hardware/arduino/boards.txt, I think the arduino core itself should compile just fine and run things (including serial and millis/delay/etc) correctly even at 20MHz (the entry should just appear in the TOOLS/BOARDS menu.):

############################################################## Duemilanove ATmega328 20MHz


(this is a copy of the atmega328/duemilanove defintion with build.f_cpu changed, and a new name.)

I'm not sure that the new bootloader speed will work, but it MIGHT...
4924  Forum 2005-2010 (read only) / Development / Re: Need quick review before board house on: May 19, 2010, 10:26:30 am
I'm a big fan of thicker traces when they'll fit...

The pads on your resistors look particularly small; you might want to play with the DRC parameters ("Restring" if this is EAGLE.)  You could go to smaller resistor packages as well (1/8 W resistor, or just closer lead spacing.

I would run SCL and SDA straight from connector to chip, with the pullup traces wiggling around as necessary...

You're paying a big price for those jumpers, both in board space and ... in the cost of the jumpers themselves (and in their complexity.)  I would have left it more like your original board with a "populate these resistors only if you need them."  But I guess it depends on the target customer...
4925  Forum 2005-2010 (read only) / Development / Re: Need quick review before board house on: May 17, 2010, 10:57:56 am
Shouldn't pin 4 of DS1307 be connected to GND and pin 3 to Vbat
It is.  Coin cells are backward that way; the bigger terminal is B+ and the "button" is B-.
4926  Forum 2005-2010 (read only) / Development / Re: Simple Arduino schematic and board? on: June 04, 2010, 04:32:05 am
Have you looked at some of the really small Arduino boards?  (Cheap, also)
As for the cheap small boards, the 18$ is not very cheap for me, because PLN/USD isn't very good.
Note that some of the small cheap boards are open-source in one form or another, so that even if it isn't practical to buy the kits or bare boards, the designs may be a good starting point.  The "Really Bare Bones Board" was placed in the public domain, for example, and I did a single-sided EAGLE-based version that is also PD.
4927  Forum 2005-2010 (read only) / Development / Re: ROARduino - A power-board on: June 05, 2010, 04:31:30 pm
I've thought about this, mostly in connection with Arduino-like board based on newer processors with weak outputs (5mA or less), rather than the AVR's rather nice 20-40mA.

The problem is that you start running into a long list of issues that are difficult and expensive to deal with:
  • "any voltage and lots of power" ?  Doesn't exist.  There are always limits.
  • Did you want to source AND sink current?  Now you're talking about a half H-bridge per pin (3 transistors, typically) rather than one transistor.
  • Wait, did you also want to be able to float the outputs so you could do stuff like Charlieplexing?  That would mean ... Um...
  • what about being able to do input on some of those pins?
  • How BIG is this going to be, once you allow for the heatsinks needed for all those high-power transistors?
  • So how much does all that cost, per pin?  And how much are you paying for the pins that  don't actually need that high-voltage, high-current, driver?
4928  Forum 2005-2010 (read only) / Development / Re: rgb led strip on: May 24, 2010, 08:12:46 pm
Better make sure you CAN cut it into 3-led segments, and exactly WHERE you can make those cuts.  For a 12V strip, you probably have parallel combinations of serial circuits of 3 LEDs in each one, so in THEORY you're fine.   But you need to cut so that you separate between the series circuits an not in the middle of them!
4929  Forum 2005-2010 (read only) / Development / Re: How many LEDs can I attach to a duemilanove alone? on: January 13, 2009, 08:09:50 pm
100 LEDs will require a driver (and wires) capable of about 2A, and/or series parallel wiring and higher voltages (call it 10W.)  That would be for EACH color; approximately 30W if you're going to turn them on all at once for pseudo-white.

This means that you'll need some sort of bigger power supply, and some sort of "LED Driver" circuit external to the arduino.

To a pretty close approximation, the Aduino, all by itself, can drive ONE led chip per pin (3 pins for an RGB led with 3 chips.)  A total of about 20 LEDs, or 6 RGB leds.  (you can do fancy things to get it to LOOK like more LEDs are on, but they mostly amount to turning on no more than 20 LEDs at a time, and switching which 20 too fast for the human eye to follow...)
4930  Forum 2005-2010 (read only) / Development / Re: How many LEDs can I attach to a duemilanove alone? on: January 13, 2009, 08:25:01 am
I'm not sure I understand if you're asking a PIN/CPU question, or a power question.  If you want a single RGB "strip", so that you're only driving 3 "signals" (changing the color of your strip, but lighting or not lighting ALL of the LEDs at once), then your main limit is the power available at a single pin, and on the Arduino board as a whole (although there are many ways to boost this.)

If you want to have the LEDs light in animated patterns or similar, then you have pin/CPU issues as well (and there are many ways to handle these as well.)

Could you clarify?
4931  Forum 2005-2010 (read only) / Development / Re: Bare PCB availability in UK on: May 24, 2010, 07:54:32 pm
There are some techniques for creating PCBs that don't requiring drilling.  Would that be worth doing to a single-sided serial Arduino clone even if it made the board significantly bigger?  You're essentially mounting normal components in a surface-mount way, which can be awkward and is usually awfully ugly...
4932  Forum 2005-2010 (read only) / Development / Re: Is arduino good choice for profes. applications? on: May 18, 2010, 03:49:58 am
The Arduino is also a fine "prototyping environment" for trying out ideas within a nice simple framework.  so you try out your code ideas using the arduino envionment.  If it WORKS, your in gravy; off-the-shelf arduino code "just works."  If it runs too slowly, you can look at the pieces of code that are likely to  to be slower, and trade them up to "bare C" coding standards.  If the code is STILL too slow, you can still try the whole thing in "bare C" within the arduino environment, maybe even with some assembler thrown in.  IF it's still too slow, you have pretty much elminated the ATmegaxx8 as the core CPU.  You can bring in an XMEGA with lots of extra memory and rewrite code to faster and bigger instead of just fast and small.  If it's still not working, it's time to look beyond the AVRs.  This is a pretty good range of info that you've discovered form your Arduino.  $100 HW  budget well spent!
4933  Forum 2005-2010 (read only) / Development / Re: Is arduino good choice for profes. applications? on: May 17, 2010, 11:25:31 pm
What Grumpy said (all of it!)

I've been told (for instance) that Arduino takes a significantly greater number of cycles to perform a task like DigitalWrite than it would if the code were written in standard C.
Yes, that's mostly true.  As a "professional", you'd be expected to determine whether or not that's relevant.  A single-task microcontroller application NEVER has to be "as fast and efficient as possible" (the way an app running on a 100+ user timesharing system ought to be), it only has to be "fast enough."  Systems FAR slower than Arduino have been successfully used in commercial applications for decades now...
4934  Forum 2005-2010 (read only) / Development / Re: Custom Ethernet Shield on: May 11, 2010, 01:35:05 pm
This one:
is almost single sided (but it's all-smt rather than all-th.)
4935  Forum 2005-2010 (read only) / Development / Re: What is the simpliest FTDI board diagram? on: May 13, 2010, 07:55:28 pm
The cheapest, easiest solution for USB connectivity is one of those cellphone USB/Serial adapters, but they don't tend to be FTDI based.
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