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4621  Using Arduino / Programming Questions / Re: Servo changes its position randomly on: June 02, 2013, 07:28:21 am
I assume that LDR refers to a light dependent resistor, and I assume you have this wired with a series resistor to act as a voltage divider with the Arduino input connected between the. This will give a voltage that varies with light level. However, it would be pure chance whether the readings corresponding to black and white balls happened to be the right side of the threshold voltage for a digital read. Before you consider trying to use the values to control anything, make sure that your LDR hardware and the software reading from it is consistently giving the correct values. I would have thought you would need to use an analog input and compare the analog reading against a suitable threshold, chosen by trial and error under realistic ambient conditions, but if you're lucky you might find that with the right series resistor you can get it to work with a digital read.
4622  Using Arduino / Project Guidance / Re: Manage SD files remotely from PC. on: June 02, 2013, 07:21:50 am
That is what I was saying. HTTP and FTP are different responses from the server. You can't put a HTTP server on a FTP port, then use a FTP program. You must use a RAW TCP type connection.

I'm puzzled about what is going on here. It's clear this is on the right lines because changing the client has changed the behaviour, but according the the evidence given it shouldn't have made any difference - the problem described was that the server did not see any incoming connect request. Unless/until the TCP connection has been established it is irrelevant what application protocol is carried over it. The only explanation I can think of is that the description of the symptoms was inaccurate and in fact we were successfully establishing the TCP connection and then failing at some later step in the process.
4623  Using Arduino / Project Guidance / Re: High resolution, high accuracy temperature sensor on: June 02, 2013, 07:16:14 am
Over what temperature range, in what environment?
4624  Using Arduino / Project Guidance / Re: Switching a solenoid between 2 different AC/DC adapters? on: June 02, 2013, 07:14:57 am
I don't follow what that circuit is supposed to do. Aren't your diodes preventing any current passing through the transistors? And, if the diodes weren't there, the transistors would be short-circuiting the power supplies.

I get the idea that you're trying to operate the solenoid(s) with different voltages to control 'velocity' - I'm guessing this means the mechanical speed of the solenoid as it operates. If that's all you want then I suggest you simply use the voltage needed to provide the higher speed and PWM it to reduce the velocity for the lower speed. This would require one power supply, transistor and flyback diode - depending on the transistor you might well need a current limiting resistor on the base. In any case the circuit would be nothing like what you have drawn.
4625  Using Arduino / Programming Questions / Re: How can I send SMS to more than one number? on: June 01, 2013, 06:54:13 pm
I want to be able to send SMS to more than one phone number (stored in phonebook) at once

Do you have some reason to think that it is possible? I would have thought you needed to send the SMS separately to each address.
4626  Using Arduino / Programming Questions / Re: converting "wiring" to C on: June 01, 2013, 06:47:54 pm
Converting the sketch to 'C' should be pretty straight forward - it is already more-or-less C++ and if you aren't deliberately using C++ features then relatively little work would be required to convert it back to 'C'. I'd be far more concerned by the fact that your sketch probably uses a runtime framework and perhaps additional interface libraries and any of these that do hardware-specific stuff will need to be ported to your new platform. Depending what features and libraries you use, that could be a huge job.
4627  Using Arduino / Project Guidance / Re: project with RGB LEDs that wont shut off. on: June 01, 2013, 06:41:36 pm
Also, it would be better to consistently hold all time values as unsigned long.
4628  Using Arduino / Programming Questions / Re: I need you ! PLEASE HELP ME ! on: June 01, 2013, 08:45:36 am
If you leave out the braces as you have then only the next line after the test will be executed because there is nothing to indicate which commands to execute.

Strictly speaking it's the next statement which is executed, and the code looks syntactically correct. However, without braces or consistent indentation to make it clear which statement(s) the coder intended to be associated with each condition, the code is a recipe for disaster. I agree with UKHeliBob that you should always use braces ({ and }) with any conditional statement to make it explicit and unambiguous which code it is intended to control. Also put each { and } on separate lines with matchng pairs indented by the same amount and the code between them indented one extra level. The IDE will apply the indentation for you if you run the Tools / Auto Format command.
4629  Using Arduino / Project Guidance / Re: line following car robot on: June 01, 2013, 08:26:31 am
The Arduino project is designed to enable you to create your own solutions. If you run into problems doing it, you can usually get help solving them via the forum. We won't do your development for you, however. If you want somebody to give you a working solution you will need to either search for other people who have solved the same problem and published their design, or go to the Gigs and Collaborations section of the forum and ask somebody to implement it for you. Note that most people would expect to be paid for working for you.
4630  Using Arduino / Programming Questions / Re: FastSPI on: May 31, 2013, 08:51:45 pm
I haven't used that library, but it seems to be a recurring theme that documentation is done as an afterthought for many open source projects and this seems to be no exception. shows a trivial example and might be enough to get you started - it also suggests that the documentation is expected to follow in later releases. I suspect your best bet would be to Google keywords from the API and see if you can track down some examples, and then reverse engineer them.
4631  Using Arduino / Programming Questions / Re: FastSPI on: May 31, 2013, 06:36:11 pm
What does "Fast SPI" mean to you?
4632  Using Arduino / Project Guidance / Re: Making two waves simultaneously without using tone() on: May 31, 2013, 06:34:19 pm
Your code seems to be incomplete. I'm not sure where the second wave comes from, but if you want to output a logic-level square wave at double the frequency of an input logic level square wave then you could use interrupts or polling to measure the input frequency and hence calculate the output interval. At that frequency range, I'd use polling.

Given that polling would give you a value for the period rather than the frequency, you could simplify the code and reduce the execution time by halving the period rather than converting to frequency and back again.

The code you already have to do the output looks OK except that your timing doesn't account for the execution time of loop() so it will slip slightly. To avoid that, replace
    previousMillis = currentMillis;   


    previousMillis += interval; 

(Where unsigned long interval = your calculated half period for the output signal.)
4633  Using Arduino / Programming Questions / Re: ISR Vector, UART issues on: May 31, 2013, 05:48:10 pm
Start by taking a look in the reference section of this site.
Of coure, I have already gone through that.


So if you want to point me somewhere, point me in the direction of some good sources to conquer the hardware serial lib, UART, etc for the arduino.

Start by taking a look in the reference section of this site. Only this time, instead of turning your nose up when you see the parts that cover C++ operators you already know about, read the whole page including the part at the bottom that provides links to the documentation for Serial and Streams. It really is pretty trivial to use.

When you've read that, look at the basic examples for the Arduino. Lots of them use the hardware Serial port. If you want to use the other hardware serial ports, just replace Serial with Serial1, Serial2 or Serial3.
4634  Using Arduino / Project Guidance / Re: Manage SD files remotely from PC. on: May 31, 2013, 05:17:41 pm
Is your client in the same network as the Arduino? Check for a firewall on your PC, and on your Ethernet router.
4635  Using Arduino / Project Guidance / Re: Unique sensor pairs? on: May 31, 2013, 05:15:20 pm
What sensor devices can I use that will only report the proximity of this fake metal detector?

I suppose you could install a magnet and use some sort of magnet field sensor to detect it. Alternatively - I know it's a wild thought - why not bury something metal under the floor and just use a real metal detector?
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