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16  Using Arduino / Programming Questions / Re: Literal conversion from short or byte to char on: April 08, 2014, 01:51:16 pm

That solution worked very well but there is something that I was strugling and I finally found out why.


Which is why you should show all your code, and not just snippets.
17  Using Arduino / Project Guidance / Re: I need help with bluetooth on: April 08, 2014, 01:48:45 pm
I just had good luck with the BlueSmirf from Sparkfun:
https://www.sparkfun.com/products/12577

If you are 3.3 V, you can just get the RN-42 by itself.
18  Using Arduino / Microcontrollers / Re: Rfid based student attendence System on: April 08, 2014, 01:20:16 pm
Spycatcher:
You forgot the most important thing: Profit!
19  Using Arduino / General Electronics / Re: autooscilating oscillator on: April 08, 2014, 11:03:38 am
You can use the arduino to drive a DDS chip. By varying the clock speed of the chip, you can change the frequency of the output signal.
20  Using Arduino / Programming Questions / Re: Implementing Cordic Algorithm in Arduino on: April 08, 2014, 10:43:57 am
http://arduino.cc/en/Reference/Setup

http://arduino.cc/en/Reference/Loop

If you want something done once, put it in setup().
If you want it done over and over, put it in loop().

21  Using Arduino / Programming Questions / Re: Re-program the Arduino Uno without losing a base (custom firmware) sketch on: April 08, 2014, 10:34:20 am
Is it that hard to make your functionality a library and hide the internals from the user? If you want users to be able to interact with it without revealing teh source code, you can always ofuscate it.
22  Using Arduino / Project Guidance / Re: Need Help for Genetic Algorithm on: April 08, 2014, 10:17:03 am
No, "genetic" a class of algorithms that mimic inheritance and natural selection to perform optimization. I am not sure what he wants to optimise, but GA's work better for simulations.

OT Fact: They are really good for "think outside the box" optimizations. The example I like is the FPGA design that used an EM quirk:

"A field-programmable gate array, or FPGA for short, is a special type of circuit board with an array of logic cells, each of which can act as any type of logic gate, connected by flexible interlinks which can connect cells. Both of these functions are controlled by software, so merely by loading a special program into the board, it can be altered on the fly to perform the functions of any one of a vast variety of hardware devices.
 
Dr. Adrian Thompson has exploited this device, in conjunction with the principles of evolution, to produce a prototype voice-recognition circuit that can distinguish between and respond to spoken commands using only 37 logic gates - a task that would have been considered impossible for any human engineer. He generated random bit strings of 0s and 1s and used them as configurations for the FPGA, selecting the fittest individuals from each generation, reproducing and randomly mutating them, swapping sections of their code and passing them on to another round of selection. His goal was to evolve a device that could at first discriminate between tones of different frequencies (1 and 10 kilohertz), then distinguish between the spoken words "go" and "stop".
 
This aim was achieved within 3000 generations, but the success was even greater than had been anticipated. The evolved system uses far fewer cells than anything a human engineer could have designed, and it does not even need the most critical component of human-built systems - a clock. How does it work? Thompson has no idea, though he has traced the input signal through a complex arrangement of feedback loops within the evolved circuit. In fact, out of the 37 logic gates the final product uses, five of them are not even connected to the rest of the circuit in any way - yet if their power supply is removed, the circuit stops working. It seems that evolution has exploited some subtle electromagnetic effect of these cells to come up with its solution, yet the exact workings of the complex and intricate evolved structure remain a mystery "

Another good reference:
http://www.talkorigins.org/faqs/genalg/genalg.html
23  Using Arduino / Programming Questions / Re: Errors like Println was not declared in the scope and many more errors. on: April 07, 2014, 06:19:19 pm
What does this have to do with arduino?

Arduino hides the main() function - how do expect to send it arguments? Instead arduino uses setup() and loop().
24  Using Arduino / Programming Questions / Re: Help needed to code an Arduino for a project. on: April 07, 2014, 06:03:16 pm
We are going in circles. We don't need to know what it physically looks like - note I said "block diagram". We need to know how it will work when connected to the Arduino. How is the motor wired? what connections are made to the arduino? what are you using to drive the motor since the arduino cannot supply enough power?
25  Using Arduino / Programming Questions / Re: Array Basics (sizeof) on: April 07, 2014, 06:00:17 pm
The parens are required if the argument is a type name.
26  Using Arduino / Programming Questions / Re: Help needed to code an Arduino for a project. on: April 07, 2014, 05:50:45 pm
How does it connect to the arduino? Can you give us a block diagram of the hardware and how it connects? So far we have nothing.
27  Using Arduino / Programming Questions / Re: Help needed to code an Arduino for a project. on: April 07, 2014, 05:37:03 pm
No, we cannot do this kind of thing by remote control. You need to see if there is a local arduino club or something to help you out. If you had the hardware designed with only software needed - as you implied in the first post - we might have been able to help.
28  Using Arduino / Programming Questions / Re: Help needed to code an Arduino for a project. on: April 07, 2014, 05:26:25 pm
Good, now program the arduino to move the motor. Since you have not given us the required details, we can't help with that. The best thing is to take baby steps. I know it is frustrating with a deadline approaching, but it is *much* better to troubleshoot something small and workable than a giant behemoth of a system. I used this approach for my senior project. I had all the components built and tested, and assembled it the night before. I turned it on at 4:00 Am the morning it was due for the first time and it worked. 8^)
29  Using Arduino / Programming Questions / Re: Array Basics (sizeof) on: April 07, 2014, 05:10:08 pm
Did you bother to read up on sizeof? It returns the size of teh object in *bytes*. The C idiom to convert this to elements is sizeof(object)/sizeof(object[0]). In the function it just gets a pointer to your array. You need to pass the number of elements as a global or another function parameter.
30  Using Arduino / Programming Questions / Re: Help needed to code an Arduino for a project. on: April 07, 2014, 05:07:30 pm
Do you have the arduino? Can you get "blink" to download to the arduino and run?

We need pin numbers and schematics for the hardware. What are you using to drive the motor? The arduino cannot supply enough current!
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