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16  Using Arduino / Project Guidance / Re: Logger shield on: September 18, 2014, 06:12:42 pm
Have you looked at the built-in example File->Examples->SD->Datalogger?
17  Using Arduino / Networking, Protocols, and Devices / Re: SPI communication to the ADXRS450 gyroscope on: September 18, 2014, 04:32:18 pm
How hard can it be? It's 'just' SPI.

There's bit order, byte order, mode, and various parity bits to get right.  That may take a very close reading of the datasheet.
18  Using Arduino / Programming Questions / Re: Arduino Uno ATMEGA 16U2 CODE? on: September 18, 2014, 06:17:48 am
Yes, it is used for USB to Serial conversion.  The firmware is in your Arduino IDE distribution:

hardware/arduino/firmwares/atmegaxxu2/Arduino-COMBINED-dfu-usbserial-atmega16u2-Uno-Rev3.hex
19  Community / Products and Services / Re: New product - Watchdog Timer Module for Arduino on: September 18, 2014, 06:12:43 am
FYI: The ATmega processor has a built-in watchdog timer.
20  Using Arduino / Networking, Protocols, and Devices / Re: SPI communication to the ADXRS450 gyroscope on: September 18, 2014, 05:58:10 am
Thanks for your reply. I removed the lines and had no succes. The output is -1 now, that's it.

I was wrong. I just looked at the datasheet again and your previous code was right.  As you send out Command-N you receive the results from the previous command (N-1).  The command and response are two different transactions.

It might be time to give up on the ADXRS450 and get a easier to use gyroscope. smiley-sad
21  Topics / Robotics / Re: Connecting Servo to the Arduino (branded) Robot on: September 18, 2014, 05:37:01 am
You should be able to use any of the following designations:
19 == A1 == TKD0
20 == A2 == TKD1
21 == A3 == TKD2
22 == A4 == TKD3

Each of those four locations on the board have three holes.  I assume one hole is Ground (Servo Black), one is Vcc (Servo Red), and one is Signal (Servo White or Yellow).  I don't think you need to use pinMode() on those pins if you use them with the Servo library .attach() but it couldn't hurt to try it.
22  Using Arduino / Project Guidance / Re: Battery Paradigm for a project that must last a week on: September 17, 2014, 09:18:18 pm
A 9V alkaline battery has about 500 mAh capacity at 50 mA so we can guerss that your circuit was drawing an average of about 50 mA for the ten hours the battery lasted.  To supply 50 mA for 30 days you'd need 36,000 mAh of battery capacity.

A 6V alkaline lantern battery has about 13,000 mAh of capacity so to get 30 days of life you'd need three in parallel.
23  Using Arduino / Networking, Protocols, and Devices / Re: SPI communication to the ADXRS450 gyroscope on: September 17, 2014, 09:00:18 pm
Code:
void loop() {
  digitalWrite(7, LOW);
  // Sending 4 bytes as a command
  SPI.transfer(0x20);
  SPI.transfer(0x00);
  SPI.transfer(0x00);
  SPI.transfer(0x00);

                         digitalWrite(7, HIGH);  // End of command
                         delay(4);
                         digitalWrite(7, LOW);   // Start of data retrieval
  
  result = SPI.transfer(0x00);
  result = result << 8 | SPI.transfer(0x00);
  result = result << 8 | SPI.transfer(0x00);
  result = result << 8 | SPI.transfer(0x00);
  Serial.println(result);
  digitalWrite(7, HIGH);
  delay(100);
}

I'm sorry I failed to mention it before but it would be highly unusual for the Slave Select pin (7) to be set HIGH between the sending of the command and the receiving of the data.  Try removing the three indented lines.
24  Using Arduino / Project Guidance / Re: Battery Paradigm for a project that must last a week on: September 17, 2014, 11:40:20 am
You have not said how much power your "powerful LED light" draws and what portion of the time the light will be at 100% vs 15%.  Do you have a multimeter you can connect in series with the battery to measure current draw?

A 9V battery going through a 5V linear regulator will throw away almost 50% of the power.   You might want to use a lower voltage battery (3.8 to 5V) and power the equipment directly with that.
25  Using Arduino / Project Guidance / Re: Using OTS RF remotes on: September 17, 2014, 11:28:48 am
Those are basic 433 or 315 MHz transmitter/receiver pairs.  They use On-Off Keying (OOK): the transmitter sends out carrier when  the input is HIGH.  The receiver send out HIGH when it detect carrier.  To send messages with them you have to modulate the carrier (turn it on and off in a pattern representing the data) and decode the data you get from the receiver.  The old VirtualWire library was used for that but has been superseded by the RadioHead library:
http://www.airspayce.com/mikem/arduino/RadioHead/

If you have a car remote you want to receive you will need to determine the frequency it uses and buy a matching receiver.  Then you have to analyze the patterns you get from it to decode the buttons.
26  Topics / Robotics / Re: Connecting Servo to the Arduino (branded) Robot on: September 17, 2014, 11:21:45 am
From reading the documentation (http://arduino.cc/en/Main/Robot) I think that TKD0-TKD3 can be use for servos by calling them pins 19-22.  You can't use Pin 9 because that is already used as the Slave Select pin for the LCD.
27  Using Arduino / Audio / Re: Using more than 16 analog inputs for a MIDI controller on: September 17, 2014, 09:58:54 am

Which potentiometer would be better for a precise controlling of those values?

Linear.
28  Using Arduino / Programming Questions / Re: Problem using while statement please help on: September 17, 2014, 09:57:00 am
A more concise way to write it:
Code:
   for (unsigned long A = millis(); millis() - A < 120000; ) {
        Serial.println(millis()-A,HEX);
    }
    break;

You do realize that this will slam the serial output with thousands of lines of text and won't do anything more useful than
Code:
delay(120000UL);
29  General Category / General Discussion / Re: how to prototype a automatic pan and tilt system capable of detecting cellphone on: September 17, 2014, 09:49:02 am
This paper covers a number of ways to detect a cellphone:
http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1021&context=ceendiss

Looks like there are no good ways to detect a cellphone.

Since you are talking about Pan and Tilt did you want to LOCATE the cellphone as well as DETECT it?
30  Topics / E-Textiles and Craft / Re: lilypad usb on: September 17, 2014, 09:25:49 am
The Lilypad USB board doesn't include connections for the hardware serial port.  If you are good enough with a fine soldering iron you can connect very thin wires to pins 20 (RX) and 21 (TX).  Pins are numbered counter-clockwise from the clipped (top right) corner of the chip. That puts pin 20 is on the left side of the chip, third from the bottom.  Pin 21 is on the left side of the chip, second from the bottom.
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