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1  Using Arduino / Sensors / Re: TVout and ultrasonic sensor issue on: August 17, 2014, 08:31:35 pm
The TVOut documentation (http://playground.arduino.cc/Main/TVout) says that on an Arduino UNO it uses Pin 11 for audio (?).  That will conflict with you using Pin 11 for Echo.  Try a different pin for Echo.
2  Using Arduino / Programming Questions / Re: Display Numbers as Words? on: August 17, 2014, 08:20:22 pm
Code:
char *ChannelNames[] = {"Potatoes", "Carrots", "Peas", "Mustard"};

for (int i=0; i< sizeof ChannelNames / sizeof ChannelNames[0]; i++) {
    // Display the names for channels 0, 1, 2, and 3
     LCD.print(ChannelNames[i]);
}
3  Using Arduino / Project Guidance / Re: Arduino mega password lock with lcd, keypad and servo on: August 17, 2014, 07:48:40 pm
Do you know how to reset the password buffer?

Looking at the library documentation (http://playground.arduino.cc/Code/Password) it appears that you do it with:
Code:
password.reset();

I would put that in displayCodeEntryScreen() which is where you go when it's time to look for the password.

I think you should roll the check for 'D' in with the already existing switch statement, rather than in its own switch statement.

4  Using Arduino / Installation & Troubleshooting / Re: bootloader help on: August 16, 2014, 09:23:27 pm
> 1- Bootloader is a software installed on ATMega chip's (present on each arduino board) by arduino iDE so we dont have the need to take the chip out everytime we want to re-program it, right?

More correctly: the Arduino bootloader programmed into the ATmega chip on the Arduino allows you to upload an Arduino sketch through a TTL Serial connection (usually the Arduino will have a USB-to-TTL-Serial converter on board).  Without the bootloader you would need a ISP device (like the AVRISP, USBtiny, or USBasp)

> 2- Bootloader is needed everytime we want to program chip directly from computer via usb port devices therefore without external programmer(ATMel-AVRISP), right?

Yes.

> 3- Bootloader software is not needed if we are programing the chip with external programer,right?(i.e. ATMega328)

Yes.  Also remember that when you upload a sketch using an ISP device you disable the bootloader.  If you want to go back to uploading over USB/TTL Serial you have to burn a fresh bootloader using the ISP device.

> 4- Imagine i buy any ATMel microcontroller for a project.
> 4a) Bootload compatible chip example - i can use arduino IDE to write code and then i can use those usb devices to program it right?

If you buy an ATmega chip with an Arduino bootloader you can upload sketches using USB/TTL Serial.  Since several generations of Arduino use the same ATmega328P chip and different bootloaders you need to know WHICH Arduino bootloader is installed in the chip you purchased.

> 4b) Bootload not compatible chip example - i can use arduino IDE to write code and then i must use external programmer? So its like, can i use arduino IDE to program any kind of ATMel chip using external programmer?

Not all Atmel chips are supported by the Arduino IDE and libraries.  Not even all Atmel AVR chips are supported by the Arduino IDE and libraries.  Not even all Atmel ATmega chips are supported by the Arduino IDE and libraries.  If you want to use the Arduino IDE and Arduino libraries it is best to stick with the ATmega8, ATmega168 or ATmega328P.  If you want to program without the restrictions of the Arduino IDE you should get Atmel Studio and visit the AVRFREAKs.net forums.
5  Using Arduino / Motors, Mechanics, and Power / Re: Driver options for the Nema17 on: August 16, 2014, 09:06:51 pm
You can get the StepStick driver from eBay for under $4.
6  Using Arduino / Installation & Troubleshooting / Re: Recovering code from Uno on: August 16, 2014, 09:03:07 pm
You can't get the source code from the Arduino since by the time it is uploaded it has been compiled into machine code.
7  Using Arduino / Project Guidance / Re: use arduino mega or not on: August 16, 2014, 09:01:03 pm
Any Arduino, even the smallest, can easily control three stepper motors.  You will need external "step and direction" stepper drivers but you can get the "stepstick" for under $4 on eBay.  You won't need the "direction" pin since the mechanism will not work in reverse.  That means three data pins for the motors.

The I2C RTC takes two pins.

That leaves about 15 pins for buttons.  You can get 16 buttons with 8 pins using multiplexing.

You may need to add some feedback switches so the Arduino can determine the displayed time and date in case of a reset.
8  Using Arduino / Project Guidance / Re: Arduino mega password lock with lcd, keypad and servo on: August 16, 2014, 06:57:38 pm
My guess for Problem 3 is that you aren't clearing the password buffer after you evaluate the password.  Since "51445144" does not match "5144" it is not recognized as correct.
9  Using Arduino / Installation & Troubleshooting / Re: Is the JP1 connector on the LilyPad Arduino Main Board a serial port or not? on: August 16, 2014, 06:46:05 pm
It is a TTL Serial port usually used with an "FTDI Cable": https://www.sparkfun.com/products/9718

Pinout is:
1: Ground
2: "Clear to Send" (CTS) signal
3: Vcc (+5V)
4: TXD (Transmit Data)
5: RXD (Receive Data)
6: "Request to Send" (RTS) signal

The Arduino software knows the baud rate used by the bootloader.  If you are using the serial port from your sketch you can choose the baud rate in your sketch,

It is NOT an RS232 Serial port so you can't connect it to a PC (9-pin) serial port without level shifters.

10  Using Arduino / Installation & Troubleshooting / Re: Trying to compile the "blink" example but I get errors on: August 16, 2014, 06:30:22 pm
You probably shouldn't use Arduino 1.5.x with the UNO.  That version is for the Arduino DUE (ARM processor).  Download and install Arduino 1.0.5.
11  Using Arduino / Programming Questions / Re: Some sketch weirdness, when servo motor runs, arduino can't process RF signal on: August 16, 2014, 06:24:45 pm
Try the decouping capacitors.

If that doesn't help enough, try running the servo wires through a ferite ring.

If those don't help enough, wrap the servo in grounded metal foil.
12  Using Arduino / Project Guidance / Re: more 53 pin digital on: August 16, 2014, 06:19:37 pm
This shows how to wire two 74HC595 shift registers together and use them to control 16 LEDs:
http://arduino.cc/en/tutorial/ShiftOut

You only have to add more shift registers.
13  Using Arduino / Project Guidance / Re: more 53 pin digital on: August 16, 2014, 10:06:35 am
Use 74HC595 shift registers to extend the number of output pins.  You only need three pins to drive all of them and each will give you 8 outputs so 13 will give you 104 pins.  You can get one on a breakout board for $2.95: https://www.sparkfun.com/products/10680

If you need to control the brightness of each LED you can use the TLC5940 LED driver (http://www.ti.com/lit/ds/symlink/tlc5940.pdf)  Each will give you 16 outputs so you only need 7 of them.  They cost 12.95 on a breakout board: https://www.sparkfun.com/products/10616
14  Using Arduino / Motors, Mechanics, and Power / Re: Direction mechanism. on: August 16, 2014, 09:58:54 am
There are several choices:

Use a single front caster wheel or maybe mount the front wheels on an axel that can turn to act as a caster.

Steer by turning the front axel with a servo.

Put tracks around the front and back wheels and use 'tank' (differential speed) to steer.

Use omni-wheels (wheels that can roll sideways) in the front.
15  Using Arduino / Programming Questions / Re: Some sketch weirdness, when servo motor runs, arduino can't process RF signal on: August 16, 2014, 09:52:59 am
Perhaps the servo is creating enough electronic noise that the receiver can't receive a good signal.

Does the receiver work if the servo control wire is disconnected but the software still tries to control the servo?  If yes, try to add some shielding.  If no, the servo library is probably trying to use the same timer as the RemoteReceiver library so you have to deal with the conflict.
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