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1  Using Arduino / Programming Questions / Re: time problem (analogRead) on: January 06, 2014, 02:42:24 pm
State change detection example gives you an idea on how to detect a signal edge. Use millis() to record the time of the signal edge. At a later time, subtract said recording from millis() to get the elapsed time.

The example demonstrates the concept using digital signals, but it can work fine for analog signals as well (you may just need to use > or < instead of ==).
2  Using Arduino / Programming Questions / Re: Arduino UNO serial.read specified command on: December 30, 2013, 01:16:43 pm
Code:
char('=a0')){
Three characters can't be made into a single character.

http://www.gammon.com.au/forum/?id=12112
3  Using Arduino / Programming Questions / Re: Check Same Condition Twice to trigger event on: December 27, 2013, 02:54:29 pm
Before posting code, use the Auto format tool to fix indenting. Ctrl + T in the Arduino IDE.

Code:
if (timeOverTempLimit > 20000 && timeOverTempLimit < 21000 )

This seems like a tedious way of doing this. Assuming you only want to send the SMS once, you should use the concept of a flag variable:

Code:
int flag = 0;

Code:
if (flag == 1)
{
  flag = 0;
  // do something once
}

Code:
if (some condition is met)
{
  flag = 1;
}

In your case, you want an "SMS Message Sent" flag variable. When you check if it has been over 20 minutes, you also check if that flag variable is NOT set before sending the message. If it hasn't been sent, you send the message and "set" the variable. Then you just have to decide what condition will cause the reset/clear the variable(maybe when the temperature is less than 28?)
4  Topics / Home Automation and Networked Objects / Re: Bedroom automation help on: December 20, 2013, 05:27:16 pm
would it be possible to use the house electricity to power the relay or will it fry it?

Both.
5  Topics / Home Automation and Networked Objects / Re: Bedroom automation help on: December 20, 2013, 12:42:54 am
So you are saying to use a remote controlled socket and let the arduino control the remote? Can't I just connect the existing wires that is connected to the wall switch and connect them to the relay?

Not unless you are absolutely 100% positive you know what you are doing; those high voltages can very easily kill you.
6  Community / Gigs and Collaborations / Re: UK-based hardware startup looking for co-founder on: December 19, 2013, 10:42:27 am
As I said: on average.

I'm not doubting that the lower 10% have it easier down under, but that has to be made up somewhere, and considering we're talking about a start-up company, who takes skilled labor and tries to generate a great amount of revenue from it, that difference will likely be made up in that arena, so it's more relevant to the context of the original thread.

I'm sure Australia has a flatter distribution of wealth; there's simply a different philosophy between the two countries.
7  Community / Gigs and Collaborations / Re: UK-based hardware startup looking for co-founder on: December 18, 2013, 11:11:23 am
I feel like an American should come in and clear up some of the info, rather than letting people who don't live here disparage our system. You don't get free healthcare here in the states (At least, not for now). Your average middle class family has health insurance that is subsidized by an employer. You also have had the freedom to go without health insurance if you saw fit. Of course, in a start-up environment, you'll have to get your own. Pension is typically done by pre-tax contributions made to a 401K, which then get invested. Considering you would only be here for 3 months, I don't see the relevance in that.

What people like to ignore (or are ignorant to) is that you'll have more take home pay in the US (on average), and can afford to pay for health insurance yourself, and make your own 401K contributions. You can see this by looking at taxes as a share of GDP, in which the United States near the bottom with under 30%, while a country like Denmark is near 50%.
8  Using Arduino / Programming Questions / Re: Sending Serial data to modify variables in arduino on: December 02, 2013, 10:23:20 pm
can't properly read 16 characters (ONLY) using the char function only. I can do it the way I explained at the beginning with strings not with characters. I just get too much "mumbo jumbo" information (yes I know its not mumbo jumbo).



Because you check if there is at least 1 character available, and then read all 16 of them. Doesn't make much sense.
9  Community / Gigs and Collaborations / Re: A Noob Question About Hiring Project Engineers on: November 26, 2013, 05:28:17 pm
What would be the proper term for someone Woz-like (Steve Wozniak -[url]http://en.wikipedia.org/wiki/Steve_Wozniak/url]) to hire? Someone who works on an Arduino boards (specifically) and connect needed boards and things?

Is the proper term engineer?
I would probably say developer is more accurate, but I don't think anyone would scoff at being called an engineer.

Quote
How would I be able to find and hire someone?
Post your project on these forums. Give a general overview of what you're looking to do (with maybe some info on the hardware/software that is being used) and solicit PMs for those that are interested. Those that message you will typically ask some questions to illicit requrirements. Once they have a solid enough understanding, they'll provide you with a quote.

Quote
What's the usual going rate for work?

Variance in locality,  level of experience and project size, means there really isn't a good answer for this

Some tips:
  • Know the scope of your're hiring for. Do you want them just to write the code? Should they create a wiring diagram that you can use to hook-up everything yourself? Should they create a fully functional prototype and ship it to you?
  • Make sure you and the person you are hiring are on the same page when it comes to the requirements and deliverables.
  • Be reachable. Don't go dark for a month and come back expecting to pick up right where you left off.
10  Using Arduino / Programming Questions / Re: Having Error Code Problems - Help Learning on: November 19, 2013, 10:57:32 pm
Quote
void setup();

Nope.
11  Using Arduino / Programming Questions / Re: Fill with zeros a number? on: November 06, 2013, 01:04:51 pm
Could you please give me some site reference about the "%03d" and what is each parameter is for?

http://lmgtfy.com/?q=sprintf+reference
12  Topics / Home Automation and Networked Objects / Re: Question about arduino communication with smart phone on: November 04, 2013, 06:14:38 pm
So back to my problem i need source code with :
1. Connection to lan + server + little web site (like remote control)
2. The arduino can control 8 relays (5v)

So you have three options:

1. Find the exact code that fits your needs perfectly. Might take a lot of Googling.
2. Have someone write the code for you. I wouldn't hold your breath unless you're opening your wallet.
2. Find code that demonstrates the concepts of your design and modify it to your liking. Sensible approach.
13  Using Arduino / Programming Questions / Re: converting captured string to floats on: November 04, 2013, 11:40:31 am
I thought there were going to be some new-fangled parsing functions included in the new Arduino 1.0 IDE, but I can't seem to find how they might be used in this case.

You have a string with various substrings deliminated by a space. strtok() allows you to iterate through those substrings.
You now have various substrings that contain numbers represented by ASCII. atoi() and atof() converts the strings into numbers.
14  Using Arduino / Programming Questions / Re: converting captured string to floats on: November 04, 2013, 10:53:46 am
Is there a better option that I should try?

Don't capture the serial data using Strings.

Store the data in a string (null terminated char array) and use a combination of strtok(), atoi() and atof() to get the three numbers.
15  Using Arduino / Programming Questions / Re: 4 Buttons - How to change activity based on which one is pressed on: October 31, 2013, 10:18:28 am
You'll want to look into the the concepts of finite state machines and blocking vs non-blocking.
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