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31  Using Arduino / Programming Questions / Re: Understanding Code on: August 31, 2014, 12:53:18 pm
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so the first line, wire.beginTransmission(104) tell the arduino to open a channel to device 104. Where is this zero?
It is in the least significant bit.
104 is hex 68
What is sent on a read is 0xD1 which is 0x68 shifted up by one place plus a 1 in the least significant bit. On a write it sends 0xD0, with a zero in the least significant bit. The least significant bit is the read / write bit.

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So we have libraries using libraries.
Yes what is wrong with that?

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So i guess then there is no fixed standard of code or commands?
Not sure what you mean. The commands are in the data sheet for the chip.

32  Using Arduino / General Electronics / Re: Arduino gets restart when operating 12V Solid State Relay on: August 31, 2014, 12:32:22 pm
I am using 16x2 LCD (6 pins), memory card (4 pins), buttons (4 pins), 2 solenoid pin, 3 pin for sensor so  have only one pin left to use,i.e.,digital pin 1
Wow, that is a million miles away from your first post.

Schematic?
Does it work with no load on the SSR?
What is the SSR wired to.

Mind reading skills zero here. You have to tell us what you have exactly if you are serious about wanting help.
33  Using Arduino / General Electronics / Re: Separate analog and digital regulators? on: August 31, 2014, 03:46:54 am
There is nothing a seprate regulator will  give you that proper decoupling will not give you.
34  Using Arduino / General Electronics / Re: Arduino gets restart when operating 12V Solid State Relay on: August 31, 2014, 03:44:50 am
They are, but the term solid state only appeares in the title and not the body. When you have been here as long as me you will find there is not much correlation between the title and the actual problem.

What the OP should have done was to supply a schematic, software and links to the relay part.
In the absence of a decent question what can you do?
He has not read the how to use the forum sticky post.
35  Using Arduino / Programming Questions / Re: simple logic wrong result on: August 31, 2014, 03:40:16 am
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so, I am very confused what is wrong here.
What is wrong is that you are being very arrogant and not taking the advice that has been given you.

You present an impossible situation because that is what you have in your mind. Yes it is impossible that code does behave like this.
So the soloution is to either post all the code or write a much smaller piece of code that shows the problem.

If you are not prepared to make that effort the. Why should anyone make the effort to help you?
36  Using Arduino / General Electronics / Re: Arduino gets restart when operating 12V Solid State Relay on: August 31, 2014, 03:24:10 am
Things to try.
1) try another pin as popins 1& 0 are used for serial output.
2) put a reverse biased diode across the relay coil.
3) try switching with no load on the relay contacts
4) add some bulk decoupling at the realy power. That is 100uF between ground and the 12V power.
5) make sure the grounds are connected together.
37  Using Arduino / General Electronics / Re: Separate analog and digital regulators? on: August 31, 2014, 01:11:40 am
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And why LC instead of RC; is there an advantage of one over another?
With an LC filter you do not get the drop in voltage that you get with an RC filter. This is because the resistance of the inductor is smaller than the resistance of the R you have to use.
Also an LC filter is a second order filter and the RC is a first order filter. The order of the filter is how quickly a low pass attenuates with increasing frequency.

I would have two separate ground plains and join them at one point.
There is no need for two supplies as shown here but it gives you the idea of two ground planes.
38  Using Arduino / Programming Questions / Re: After set a watchdog,the mcu died.I can't reset it though the Reset pin on: August 30, 2014, 05:27:21 pm
No it didn't , that was for posts in the body of the thread not attachments.
39  Using Arduino / Project Guidance / Re: First Project Help - Digital Potentiometer on: August 30, 2014, 05:11:28 pm
In the past I have used the TDA7318, you get a bit of a graphics equalizer with that one thrown in.
40  Using Arduino / Project Guidance / Re: potentiometer help on: August 30, 2014, 05:08:39 pm
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I was going to be using these ones
Poor choice, they are not very mechanically robust and will not stand the amount of ware you will inflict. It is normal to use wire wound pots for angle sensing. Yes I know these are expensive but they are accurate and will stand the ware.
41  Using Arduino / Project Guidance / Re: use arduino to control an adjustable boost converter? on: August 30, 2014, 03:08:00 pm
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Oh and resistance will not be adjustable.
Good job because that is a property of the load not the power supply and so impossible to do.

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Perhaps I would be better off building my own converter circuit?
How good are you at electronics?
That is a very difficult / impossible project for a beginner. You will have to use a PCB and get the design right. I have never known a professional power supply engineer get it right first time, it normally takes three iterations.

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but most of them in the 10 amp range are manually (via an adjustment screw)
You can normally replace that with a varying voltage from the smoothed PWM of an arduino.

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or way to big.
Yes your size requirements are pushing it but just about possible.

By the way how long do you want the batteries to last?
42  Using Arduino / Project Guidance / Re: Arduino to change pattern of 5v square wave? on: August 30, 2014, 03:00:19 pm
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if the wheel that the input side is reading has 3 notches that the hall effect sensor reads, can the Arduino take that particular square wave and output something as if the input wheel was a 5 notched wheel?
This is a lot more difficult than you might think.

This is because in effect you are requiring software to predict the future. While you can do this for specific rigid cases it is hard / imposable to make a universal one.
The closest you can get is a sort of averaging, you get this with a circuit called a "phase locked loop"
http://en.wikipedia.org/wiki/Phase-locked_loop
This can be implemented in software although it is more usual to implement it in hardware. Basically you have to divide down to get a mark / space ratio of 1:1 and then multiply up to get the frequency you want.
43  Using Arduino / Project Guidance / Re: Handheld terminal suggestions welcomed on: August 30, 2014, 02:54:03 pm
There are a number of different terminals it could emulate.
http://en.wikipedia.org/wiki/Terminal_emulator
Has a list of some of them.
44  Using Arduino / Programming Questions / Re: Understanding Code on: August 30, 2014, 02:48:29 pm
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So if i am reading the data sheet right, it says send a 0 to read and a 1 to write before you go on to the next byte. This is sent after the address is sent.
No it is sent with the address as the least significant bit.

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Am i right to assume the wire.read and wire.write commands take care of this!
Yes this command shifts the address bits one place to the left and adds 0 or 1 as appropriate but it is all sent out as one byte.

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So how do you find out what these are for a given library?
It should be in the documentation of the library, if not look at the code of the library. Ultimately the numbers you need to send are in the data sheet of the device.   
45  Using Arduino / Programming Questions / Re: Galileo: my servo runs only in one direction, it doesn't turn back on: August 30, 2014, 02:42:27 pm
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No, it doesn't need its own power because the Intel Galileo provides enough power for it.
True the Galileo comes with a 3A supply, but you have to consider if your servos are generating enough interference to disrupt your processor.

So it is not just a matter of having enough available current, your servo supply have to be decoupled.
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