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1  Using Arduino / Sensors / Re: Barometric Presure sensor BMP180 on: July 24, 2014, 07:07:10 pm
I think I had that sort of problem with the casting as well.  Not sure now,  it was a couple of years ago.  It took a while to get it to work,   I went through all those shift manipulations looking very closely at the bosch description.   It appears that some of the library code that people published for this device,   they never even tried running it.

I also recall seeing somewhere,  an alternative processing scheme that someone devised,  which used float instead of int ( or maybe the other way around ),   to get an output with less bit errors in it.   It looked very interesting but I did not implement it.
2  Using Arduino / Sensors / Re: Barometric Presure sensor BMP180 on: July 24, 2014, 07:01:15 pm
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Also, the code i tested it with had altitude input, for a more exact pressure output.

This statement makes no sense.   This device measures pressure.

Knowing any other outside information ( other than the temperature,  which it measures itself ),   cannot make the pressure output "more exact".

Outside information can be used to make the altitude calculation "more exact".
3  Using Arduino / Programming Questions / Re: Why My Program Does Not Exit from If statements on: July 24, 2014, 06:56:02 pm
Which if( ) statement do you think that it is not exiting from ?

Your code appears to be incomplete.   It has mismatched braces at the end of it.
4  Using Arduino / Programming Questions / Re: Arduino Uno, I2C, Wire.endTransmission(); freeze on: July 23, 2014, 11:14:03 pm
Does anyone else find it is slightly disturbing that pages like this one ( which is the first one that Google brings up )

http://playground.arduino.cc/Main/WireLibraryDetailedReference#wire

don't even mention any Wire.Write( ) function ?

No wonder people get confused.
5  Using Arduino / Programming Questions / Re: Arduino Uno, I2C, Wire.endTransmission(); freeze on: July 23, 2014, 11:10:13 pm
What do you expect Wire.write( byte 0x00 )  to do ?

What is the I2C address of the slave I2C device you are attempting to communicate with ?  [  Hint,  0 is not a valid I2C bus slave address ].

How many paramaters does the I2C  write( ) function require ?  [  Hint:  not the same number as SPI ]
6  Using Arduino / Programming Questions / Re: Losing variable value when adding function to code on: July 23, 2014, 11:06:28 pm
If m is intended to be a global variable,    then you should not also use it as the name of one of the parameter arguments to your function.
7  Using Arduino / General Electronics / Re: Arduino Nano not Triggering a Relay on: July 23, 2014, 08:27:04 pm
did you connect the ground of the arduino to the ground terminal of the relay ?
8  Using Arduino / General Electronics / Re: What's this peice called? on: July 23, 2014, 08:24:47 pm
It is probably a small resistor.

Can't you solder the old one back on again ?
9  Using Arduino / General Electronics / Re: Wind generator for 12v battery - no controller? on: July 23, 2014, 08:18:48 pm
It is not actually a $1 item until the end of the auction.
10  Using Arduino / Programming Questions / Re: Trough Detector on: July 23, 2014, 08:00:22 pm
analogWrite( ) is expecting an integer between 0 and 255,  not a float.

Rather than relying on some implicit conversion to occur in the function call,   I would be converting the value beforehand and checking it's limits.
11  Using Arduino / Programming Questions / Re: Help in uploading programs to lilypad mp3 player on: July 23, 2014, 07:55:38 pm
Since nobody else can answer your question,   I will have a go,  although I would not claim that this is one of my areas of expertise.

I've recently acquired some cheap and bootloaderless pro mini clones, and encountered the same kind of difficulties,  although I did eventually get some of them to work.

General advice. 

Double check all your wiring connections.
Make sure the device has power. 
Check that 5V is actually present on the power supply pin.
Try googling any error messages you get to see if any bloggers have previous encountered and solved the same problem.

If neither method is working for you,  then unfortunately the odds are that your device is broken.
12  Using Arduino / Programming Questions / Re: Adding character to string on: July 23, 2014, 05:36:25 pm
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buffer[bufferCount++] = c;
                        buffer[bufferCount] = 0; // append null terminator

Why does one add a 0? And won't that overwrite the char added in the line over?

Suppose bufferCount is already 2.    This code will put c into element [2]  (  note,  this is the third element of the array ),     and then increment bufferCount to 3,    and put a zero byte into element [3].

The next character you get will put the next c into element [3],   and yet another zero byte into element [4].

This method is intended to ensure that,  whenever your message ends,  your character array will always have a zero byte at the end of it.

13  Using Arduino / Sensors / Re: MPU 6050's red light blinking? on: July 23, 2014, 05:24:26 pm
the mpu6050 is a chip,  which does not have a red light on it.

The tiny pcb module which some other company made,  might have a red light on it.  There are many such modules.  Try to find a schematic for yours.  I have not seen one with a blinking light, myself.  It could just mean "power is on",  or a whole bunch of other imaginable things.  I'd be guessing.

It should not matter, as long as you can get data from it.
14  Using Arduino / Sensors / Re: MPU6050 arduino code on: July 23, 2014, 05:19:56 pm
Start with simple projects to learn to understand the arduino programming arrangment.
Buy a book to learn about C/C++.

You do not have to put the .h file into the other files.

Start with a simpler application to understand what I2C is and how it works.
15  Using Arduino / Programming Questions / Re: Help with boolean query, 'const char*' to 'const unsigned char*' on: July 22, 2014, 06:43:12 pm
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but I really don't know why it is complaining about that.

It is complaining because it is an invalid conversion from one type to another type.
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