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46  Forum 2005-2010 (read only) / Troubleshooting / Re: Arduino crashing at random on: June 24, 2007, 05:53:52 pm
If it's a switch pullup resistor it could be a much smaller resistor couldn't it?

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The resistor has 10W 8 (Ohm) 2 J written on it... does this mean anything?

A quick response would be much appreciated (this is for my University project which is due next week!)
47  Forum 2005-2010 (read only) / Development / Re: What's consuming all the power on Mega board? on: October 16, 2010, 05:13:07 am
 If you check around the online electronics shops you'll find a regulator that will viciously filter automotive power to +5volt using a switching regulator that will work much better.  Automotive power can kick out huge voltage spikes and vary wildly at times.


48  Forum 2005-2010 (read only) / Development / Re: New Single Sided Serial Arduino clone BETA TES on: December 21, 2007, 11:24:24 pm
Like the bare bones board it's intended to be programmed and shoved in a project.

A USB to TTL cable is 20,

Ordinary serial to ttl cable is easy to make and the parts fit in a back shell.

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I don't think it's a good idea removing Serial circuitry and connection of a Arduino Serial Single Sided.  will become a Arduino TTL Single Sided.

Harder and more expensive to connect.
49  Forum 2005-2010 (read only) / Development / Re: PCB Roadblock: Using Surface Mount 168? on: December 20, 2007, 07:55:04 pm
Another method is to leave holes in the board for the  ICSP and jam a connector in. It's crude but will work for a few insertion of pins.

I've even seen it done wherever the engineer could find room for single pins, of course hooking it up took a cut up header with wires to a connector that the programmer could plug into. Dirty but it worked and if it failed you solder short pins in and use the other cable. smiley-wink

You can have the chips preprogrammed. There are adapters available that will let it plug into a programmer I think atmel either has those or can point you to them.  If you do that it would be best if you did the programming and shipped them to the board house. Per piece prices for that or ouchy *if* they can even do it.

For one board house a company I was at shipped all the programming stuff to them and had an engineer go there and teach their people. There were several thousand chips to do so it actually was cost effective.  It was still about 50 cents a chip which is stiff if you're doing 10,000.
50  Forum 2005-2010 (read only) / Development / Re: Tin whiskers? on: December 20, 2007, 08:29:32 pm
Tin whiskers are a problem. That's why when you design something you expect every bad thing to happen and have multiply redundant safeties.

http://nepp.nasa.gov/WHISKER/

To remove the tin it one company I worked for shipped it out. The reason is that the solder has to be regularly tested and there are companies that specialize in removing the tin. This was for Class 3 soldering to mil-spec.

Conformal coating can help.

From the above website Paralene seems to be somewhat resistant. From experience it's nasty vicious stuff to get through to repair stuff. It slowly boils off if heat is applied and sucks the heat away.
It's very expensive to apply and only used on assemblies needed extremely high reliability.

Conformal coating isn't perfect esp. in extremely high humidity according to that article.
51  Forum 2005-2010 (read only) / Development / Re: Solar powered standalone Arduino? on: July 06, 2007, 03:04:04 am
Use the maximum possible power consumption for the device and battery charging for reasonable solar energy reception. That would cover you for a project though it's expensive if you wanted to make several thousand of them. In that case you'd either use your own generated data or try and figure it out from the datasheets and how the circuit works. Hrm... an Arduino to monitor the current of an an Arduino or other device and remotely report back via one of the radio devices. Busy Busy smiley

This link
http://www.techlib.com/reference/batteries.html
Seems to imply that mAh/ma=hours so mAh=hours*ma  so 12 hours at 200ma neads 2400mAh just to run the Arduino at maximum for that time. There are also issues with the voltage dropping that you may need to address depending on your circuit.

For batteries, none of them are real easy though lead acid is not too difficult.

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hey

it's still a design thing... you have to do the  math smiley

D

Yes, exactly.  How do I calculate the draw in amperage and the voltage requirements of an arduino-based device in a given configuration?  Any pointers on where to find such advice?

How do i calculate the amperage and voltage requirements for an arduino-based device that has (for example) a temperature sensor and zigbee trasmitter that wakes up every minute and reports back to home base?  



52  Forum 2005-2010 (read only) / Development / Re: Using the USB bit of the NG for another projec on: July 06, 2007, 03:10:43 am
Hrm. You could steal one of the digital pins and upon getting a magic number over the serial port the Arduino reboots itself. smiley-wink It does eat up a smidge of code.

You'd have to alter the upload code of the arduino to send that string which is beyond my skills just now.

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RTS and DTR are two of the hardware handshaking lines for the serial communication.  We've been trying to figure out a way to use them to automatically reset the Arduino board when you upload a new sketch (so you don't to press the reset button), which is why the resistors are shown on the schematic.  In fact, those resistors aren't mounted and you probably don't want to include them (you don't want those lines connected to reset).  The X3 that you've circled is just a group of 4 unused pads on the Arduino board - those signals aren't used for anything (and aren't connected together), but we wanted to break them out in case someone found a use for them.
53  Forum 2005-2010 (read only) / Development / Re: Using the USB bit of the NG for another projec on: July 06, 2007, 03:07:55 am
If you get it working you can use the
http://www.sparkfun.com/commerce/product_info.php?products_id=8165

Arduino serial USB board that has all those parts on it in a nice package

You could even use Processing to talk to the device or let the device talk to Processing.

It needs power ground TX and RX

http://www.arduino.cc/en/Guide/ArduinoMini


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Hi,

I would like to add USB functionality to one of my PIC projects and I thought the best way of doing that would be to 'borrow' the USB bits of the NG circuit diagram  :smiley I do have a few questions..
54  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: 30720 bytes maximum sketch size, if not enogh? on: June 20, 2010, 10:04:25 am
I'd wondered about using an SDcard to hold code which can be swapped in and out. I have no idea about how to accomplish that.
55  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: please add a jumper to disable auto reset on: June 20, 2010, 10:13:42 am
You could put a cut point on the board. Two through hold pads with a trace between them. Remove the trace if needed. If reset is then desired you either put a jumper header in or solder a wire between the holes.

56  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: Why does this thread continuously update? on: June 20, 2010, 10:15:10 am
It could also be a password collector that is malware related.
57  Forum 2005-2010 (read only) / Bugs & Suggestions / Re: short when powered by usb on: November 25, 2007, 10:38:13 am
I wonder if a compliant hub wouldn't be in order? Preferably one that had an external power supply.
58  Forum 2005-2010 (read only) / Interfacing / Re: Need help in figuring out what chip this on: January 23, 2011, 01:51:03 am
Google Spyder Tadao Circuit Board and you can on some pictures barely make out the microchip logo so it's a small PIC processor. Arduino can easily do that.

The TI dev board is cheap but they don't do much with helping Linux users use their boards though that may have changed since last year. If you have windows I'd try it just for the experience.

59  Forum 2005-2010 (read only) / Interfacing / Re: Sparkfun 6dof IMU - ITG-3200 + ADXL345 on: November 22, 2010, 01:15:15 am
Post a picture of your wiring, well lighted.

Post your code.
60  Forum 2005-2010 (read only) / Interfacing / Re: works: MIDI-IN: code + schematics on: July 05, 2010, 02:10:52 am
The resistance is RBE and is mentioned in the datasheet. It's measured in kohms from 10k to 1meg. And it does cut down noise. It also has an affect on Ton.

http://www.fairchildsemi.com/ds/4N/4N28-M.pdf



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