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6181  Topics / Home Automation and Networked Objects / Re: Twitter based webcam trigger on: December 11, 2011, 11:51:58 am
I think the Arduino may not be robust enough.  Perhaps something like a BeagleBoard ($150) would work.  It runs Linux and can use USB peripherals such as a webcam and a WiFi adapter.  It should be able to do the Twitter interface, image capture, and flikr upload.
6182  Topics / Robotics / Re: Slot car speed control via Arduino on: December 11, 2011, 11:41:53 am
I thought the game controllers would be talking to the PC over Bluetooth.  The PC talks to the Arduino over USB.  Even if the PC has an external USB Bluetooth adapter it should not cause any problem with an Arduino on the same USB bus.  If the PC only has one USB port available, get a USB Hub.
6183  Using Arduino / Programming Questions / Re: Sparkfun Fingerprint Scanner "FIM5360N-LV" on: December 11, 2011, 11:26:10 am
Note that the datasheet says the serial I/O is done at RS232 levels +/-3 to +/-12V and not TTL levels 0-5V.  You will need a level shifter such as the MAX232 to convert the data levels.
6184  Using Arduino / General Electronics / Re: High temp sensor on: December 11, 2011, 08:53:57 am
A glass-bead thermistor (temperature sensitive resistor) can handle the temperature, easy to read, but not so easy to calibrate.
6185  Using Arduino / Storage / Re: Reading Camera Data on: December 11, 2011, 08:45:45 am
Does the camera act as a USB mass storage device when connected to a USB host?  If so a USB Host shield might allow the Arduino to read the camera contents without taking the SD card out of the camera.

What are you trying to accomplish?
6186  Topics / Robotics / Re: Slot car speed control via Arduino on: December 11, 2011, 08:37:36 am
What you want to do is not too difficult.  Your PC would send values via the serial port whenever the joystick moved and the Arduino would use the value to control the six PWM output pins.

The PC might send "A0," to set channel A to level 0 and "B128," to set channel B to half power and "C255," to set channel C to full power.  The Arduino would make note of the letter to determine the channel and set value to 0, accumulate each digit (value = (value * 10)+(newDigit-'0')smiley-wink, and when the ',' arrives, analogWrite(channelPin,value);  Very simple!
6187  Using Arduino / General Electronics / Re: Step-Up/Step-Down on: December 11, 2011, 08:20:57 am
Linear Technologies has a 5V chip that take 1-10V input and sources 1A.  Digikey has them for $6.50 each.

Texas Instruments has a 5V Buck/Boost regulator that runs on 1.5-40V and sources 1A. Digikey as them for $5.10.

Try the parametric search at to find other possibilities.
6188  Using Arduino / Programming Questions / Re: Sparkfun Fingerprint Scanner "FIM5360N-LV" on: December 11, 2011, 07:50:34 am
Thank you so much for the help. i try that, but nothing found on serial monitor  smiley-confuse
Until you get a proper response for the RequestConnection command you will not be able to use any other command.  Let me know when you get it working.
6189  Using Arduino / Project Guidance / Re: Maybe Arduino is something for me?? on: December 10, 2011, 08:41:00 am
The Arduino can easily do what you want, perhaps with a little additional hardware such as two Parallel-in/Serial-out shift registers.  That would allow you to capture 16 bita at one time.

The conversion from Grey to Binary is fairly easy and the Arduino can do it.
6190  Using Arduino / General Electronics / Re: Powering Arduino Uno on: December 10, 2011, 07:52:29 am
The resulting voltage (4.8 or 6.0) can be hooked directly to the Vin pin of the Arduino.

Too low a voltage for Vin. Arduino spec for Vin:

Input Voltage (recommended) 7-12V
Input Voltage (limits) 6-20V

OOPS!  You're right.  I meant to say "directly to the +5v pin".  Sorry.
6191  Using Arduino / Project Guidance / Re: Weigand26 RFID + UDP doesn't send variable on: December 09, 2011, 09:32:23 pm
reader1 is an integer, not a string.
6192  Using Arduino / Installation & Troubleshooting / Re: Seeeduino V2.21 cannot upload scretch when connected the a vibration switch on: December 09, 2011, 09:25:18 pm
You have three wires connected to the Arduino.  Try disconnecting one at a time to see which cause the problem.  Let us know which and we might be able to figure out why a button on D2 is interfering with uploading.
6193  Using Arduino / Programming Questions / Re: Sparkfun Fingerprint Scanner "FIM5360N-LV" on: December 09, 2011, 09:16:31 pm
You should probably start with the CMD_REQUEST_CONNECTION command.  Once you have that working and you get a valid response back you can go on to the more complex commands.

Command: 0x01
Param1 : 0
Param2: 0
Data Size: 0
Error Code: 0

I think that when you put it into a packet it will look like this:
byte RequestConnection[] = {
0x7e,                          // Start Character
0x00, 0x00, 0x00, 0x01,  // Command = 1
0x00, 0x00, 0x00, 0x00,  // Param1 = 0
0x00, 0x00, 0x00, 0x00,  // Param2 = 0
0x00, 0x00, 0x00, 0x00,  // Data Size = 0
0x00, 0x00, 0x00, 0x00,  // Error Code = 0
0x00, 0x00, 0x00, 0x01   // Header Checksum = 1

Then you send it to the device with a loop:
NewSoftSerial FingerprintReader(2,3);  // Use pins 2 and 3 for serial I/O to reader
for (int i=0; i<(sizeof RequestConnection / sizeof RequestConnection[0]); i++)
    FingerprintReader.print(requestConnection[i], BYTE);

After you send that you should take any characters the fingerprint reader has to send and display then on the Serial Monitor as Hex:
void loop()
    if (FingerprintReader.available())
        Serial.print(, HEX);
        Serial.print(" ");

Then you can see if the result is correct:
7e 0 0 0 1 0 0 0 1 0 0 0 A 0 0 0 0 0 0 0 0 0 0 0 C

The first 0 0 0 1 is an echo of the CMD_REQUEST_CONNECTION command.
The second 0 0 0 1 is the RESULT_SUCCEEDED result
The 0 0 0 A is the count of registered fingerprints (assuming you has 10)
The eight 0's after that are the Data Size and Error Code
The 0 0 0 C at the end is the header checksum.  If you don't have 10 users the checksum will be different.
6194  Using Arduino / General Electronics / Re: Powering Arduino Uno on: December 09, 2011, 08:47:32 pm
I'd use a 4 x or 5 x AA battery holder and put in rechargeable NiMH AA cells. The resulting voltage (4.8 or 6.0) can be hooked directly to the Vin pin of the Arduino.  I'd go with 4 cells because some add-on devices might not be able to take 6V safely.  The 4.8v should be just right for the electric motors and should be enough for any 5V device.  For any 3.3V devices you can get that from the 3.3V pin of the Arduino.
6195  Using Arduino / Project Guidance / Re: Addressable RGB LED control? on: December 09, 2011, 12:35:21 pm
The BlinkM ( is an addressable RGB module.  It uses a four wire bus for power and signal and you can put up to 127 of them on the bus.

You could also bet some addressable RGB light strips and separate them into individual modules:
They also use a four wire bus.
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