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1  Using Arduino / Project Guidance / Re: Help me please on: March 14, 2013, 12:49:10 pm
Take a look here:
http://www.rcgroups.com/forums/showthread.php?t=1305226

Good luck!
2  Using Arduino / General Electronics / Re: Presence detector on: March 05, 2013, 02:42:32 am
So, you want to just use the RE 200 B sensor from the board -- but not the board?

Pin 1 -- Vdd -- Directly to +5VDC
Pin 2 -- Vout -- 47k ohm resistor to Pin 3 (ground)
Pin 3 -- Ground

You can attach Vout (pin 2) to an Arduino analog input pin. I might place a 0.1uFd in parallel with the resistor.

You should get readings from 0 to 800 or so, methinks.
3  Using Arduino / Project Guidance / Re: Humanless cab - battery simulation on: March 03, 2013, 06:52:20 am
It looks like the Adafruit part is sold out.

Here's another http://www.sainsmart.com/sainsmart-1602-lcd-keypad-shield-for-arduino-duemilanove-uno-mega2560-mega1280.html
4  Using Arduino / Project Guidance / Re: Humanless cab - battery simulation on: March 03, 2013, 06:40:41 am
You could use the Adafruit LCD shield at https://www.adafruit.com/products/772

It has a few buttons on it for start/stop and the various loads.

It is a kit, but it is reasonably priced and comes with an Arduino library to ease your coding chores.
5  Using Arduino / General Electronics / Re: LDR response time on: March 03, 2013, 06:25:22 am
Of course, a photodiode like the PiN diode sold by Sparkfun at https://www.sparkfun.com/products/9541 will be faster than an LDR, your circuit should be fast to a human.  How about posting a schematic and you code?
6  Using Arduino / Programming Questions / Re: Momentary switch with latching code on: March 03, 2013, 06:12:11 am
Nice work astro. Karma bump.
7  Using Arduino / Sensors / Re: Ebay HC SR04 Ultrasonic, limited range? on: March 03, 2013, 01:21:14 am
Could it be that your first tests used a different power supply? My first thought is that the reduction in range is due to a reduction in power of the ping.
8  Using Arduino / Sensors / Re: Questions with IR remote on: March 03, 2013, 01:17:40 am
The path "/Users/username/Documents/Arduino/libraries" looks like a Windows path.  Does your Mac use the same file structure?
9  Using Arduino / Programming Questions / Re: Programming Style on: March 02, 2013, 11:56:46 pm
cjdelphi,

I don't know if you meant to or not, but I like to place a space between the code and the closing semi-colon.

Like this:
Code:
   function definition ;

rather than this:
Code:
   function definition;

I don't mean to be trolling...
10  Using Arduino / Project Guidance / Re: Tic Tac Toe vs. AI on: March 02, 2013, 11:46:56 pm
I wrote a Tic Tac Toe program a million years ago on an 8080 CPU-driven SBC. Mine was competitive and would never lose (tied a lot, though).

A thought -- there are only three first moves: corner, side, or center.  You can write the code to "rotate" its thinking to adjust for which corner or side is first selected. This reduces the code when being competitive.

I await the code...
11  Using Arduino / Project Guidance / Re: Measuring sunlight intensity with BPW34 pin diode and Arduino UNO? on: March 02, 2013, 11:37:38 pm
The ReadAnalogVoltage code should work out of the box, methinks.

The only caveat is that the A0 pin will read an A2D value between 0 and 1024, with 1024 being 5V.  The PiN diode with no load might go up to 350mV, so your circuit's highest possible digital value is 72.  So be prepared for low readings.

A last thought:  the PiN diode's strength is its sensitivity and fast reaction time -- neither needed in your project. A LDR is probably a better sensor for the project.

Attach a picture when you are done...
12  Using Arduino / Project Guidance / Re: Measuring sunlight intensity with BPW34 pin diode and Arduino UNO? on: March 02, 2013, 11:20:18 pm
You are nearer than you think.  Use a 10k resistor in series with the trimpot.  When the trimpot is adjusted to 0 ohms, you have 10k total. When the trimpot is adjusted to 10k, you have 20k. I really don't think that the trimpot will be needed, but it might. smiley

The 1uF cap is a little large, but might do. Again, the cap is probably not needed either.  Make sure that, if the capacitor is polarized, you place the negative side to ground.

The ReadAnalogVoltage reads A0 and should work.  I'll review the code to see if it needs a tweek. The PiN diode won't generate much voltage at full light.

Attached is a new schematic with the trimpot and resistor in series, and a polarized cap. Again, the trimpot and cap may not help much.
13  Using Arduino / Project Guidance / Re: Feasibility of "vending Machine" type lockbox? on: March 02, 2013, 03:44:40 pm
You will need to think about how you are going to change the code to get a key. After it is used once, the code to get key 14 will need to be changed. Would you want to download new codes or use a DIP switch in the box?

I like your spirit. This will be a little difficult for a newbie, but not impossible.
14  Using Arduino / Project Guidance / Re: Measuring sunlight intensity with BPW34 pin diode and Arduino UNO? on: March 02, 2013, 03:35:31 pm
Here is a simple circuit that would read the voltage across the PiN.
BillO's trimpot idea has merit.  These components don't generate much power and 10k might load it down.
I added a 0.01uF capacitor to stabilize the voltage a little.  Try it with and without to see if it helps.
15  Using Arduino / Project Guidance / Re: 64 analog reads on: March 02, 2013, 11:03:44 am
You will need external analog multiplexers like the ADG1606 here:http://www.analog.com/en/switchesmultiplexers/multiplexers-muxes/adg1606/products/product.html

Four of these hooked up to analog input pins, and a few digital output pins for control and you can read 64 voltages.
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