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24466  Using Arduino / General Electronics / Re: Split power supply on: February 26, 2011, 12:28:40 am
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the cheap and minimal-external-component voltage inverter chips are all smd!
Yes that is the way of things nowadays, it is forcing me increasingly down the surface mount route. That's why I built my CNC machine to make surface mount PCBs.
http://www.thebox.myzen.co.uk/Hardware/CNC_Conversion.html
24467  Using Arduino / General Electronics / Re: Photocell as on/off switch on: February 26, 2011, 12:26:19 am
You are always going to use some power checking the photo cell is dark, it's like a stand by state.
It is best if this state is handled while the processor is stopped, however this circuitry will still need power.

One approach is to send the arduino to sleep for say one second, then wake up check the photo cell and go back to sleep again. You can do this on a timer interrupt cycle. It saves some power.
24468  Using Arduino / Project Guidance / Re: Geiger counter/Scaler program questions. on: February 26, 2011, 12:18:23 am
I am not sure about getting a square wave from a GM tube it is more like a pulse.
I would recommend that you get one edge of this signal to trigger an interrupt and let the ISR do the counting. Then use the millis() timer to see how many counts you get in a second to give you the rate.

http://www.arduino.cc/playground/Code/Interrupts


Are you going to incorporate dead time correction or do you want just the raw rate you read?
24469  Using Arduino / Project Guidance / Re: Simplifying code on: February 26, 2011, 12:09:16 am
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instead of having to write out elSegment(int,value) for each one.
The trick is to use an array to hold say the pin number. Then you use a for loop and the index variable of the loop becomes the index of the array to give you the pin you want to address.

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A way to include a set number of loops
Hint you can nest loops within loops.

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A means, if possible, to fade my El wire
I don't think this is possible, sorry.
 
24470  Using Arduino / Project Guidance / Re: Arduino + graphical LCD and video input? on: February 26, 2011, 12:04:50 am
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How do you interface the Arduino to the video board?
Sorry you can't.
The arduino is not fast enough nor does it have enough memory for this.
24471  Using Arduino / Audio / Re: Crummy Digitizing on: February 26, 2011, 12:00:28 am
I would agree with that.

You can use SD cards to read data from but they are too slow to write it in real time. External SRAM is the way to go. However, I am not sure if I2C SRAM will be fast enough. SPI will be faster, with parallel SRAM faster still.
I have bought some SAM chips to try this out but I have not got round to doing this yet.
24472  Topics / Science and Measurement / Re: controllin dc motor with lm35 using arduino. on: February 25, 2011, 05:54:42 pm
For motors you will need some hardware to drive them. See:-
http://www.thebox.myzen.co.uk/Workshop/Motors_1.html
24473  Using Arduino / Audio / Re: Crummy Digitizing on: February 25, 2011, 05:52:41 pm
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You are limited by RAM
True there is only 2K of RAM for everything so there is no way you can record anything over a second.
24474  Using Arduino / Project Guidance / Re: [C++][FanController] Has it been done, or am i the first? on: February 25, 2011, 05:48:57 pm
Yes there is but that's not what you asked.

You use the Serial.print() on the arduino and then on the computer you write a program (in what ever language) to gather the data from the serial port and put it into a file.
I would recommend processing as a free language.
24475  Community / Gigs and Collaborations / Re: DIY Physics Lab Equipt on: February 25, 2011, 05:44:51 pm
I would recommend that you make the arduino oscilloscope lots of bangs for your buck.
24476  Using Arduino / Displays / Re: shiftreg alternate IC on: February 25, 2011, 05:41:34 pm
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Can I replace the SN74LS164N in this project
Quite simply yes.
24477  Using Arduino / Project Guidance / Re: [C++][FanController] Has it been done, or am i the first? on: February 25, 2011, 05:38:36 pm
Yes that is C running on a computer with a file storage system. You are
on an arduino with no file storage system. There is no physical place to put the file. So fprintf() will not do anything for you.

24478  Using Arduino / Project Guidance / Re: [C++][FanController] Has it been done, or am i the first? on: February 25, 2011, 05:28:47 pm
What file? The arduino has no way of writing to files. Where are the files stored?

You can write to an SD card but not with this. You need an SD shield.
24479  Using Arduino / General Electronics / Re: Rotary encoder, messy signal? on: February 25, 2011, 05:24:09 pm
Forget a software solution, that only masks the problem and reduces the maximum speed. This is the way to do it:-



You can miss out the 74LS74 if you want to use the software to sort things out, but the capacitors are a must and the schimitt buffers help as well.
24480  Using Arduino / Project Guidance / Re: Powering and controlling groups of fans (12V DC) on: February 25, 2011, 05:17:23 pm
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So said Transistor could be used to VARIABLE speed,
Why did you not read the links I posted at the start of this thread. If you had then all these questions would have been answered.
If you did not understand the links then why did you not ask about what you didn't understand.
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