[Michael]

What do you mean by “the 2 in 1 sketch”??? What is that?

[Michael]

Pin 23 (A0) is not in use, so yes you can use this pin to control a MOSFET. There is no pad to solder to, so you would need to solder to pin 23 on the back of the board. Is that what you mean?

I do not quite understand your question about “deleting button alarm”. This button is connected to pin 24 (A1), not pin 23. Yes, you can use this pin, also. Instead of button, you connect a MOSFET, right?

To use this pin, set it as an output pin:

pinMode(A1, OUTPUT);

To set it high (5v):

digitalWrite(A1, HIGH);

To set it low (ground):

digitalWrite(A1, LOW);

Is that what you mean?

[Michael]

The pins are RTS, RX, TX, 5V, CTS, GND (RTS is the green wire and GND is black). The board has markings GRN and BLK to match up colors on a standard FTDI serial cable.

[Michael]

You cannot capture color information with the Video Experimenter. The chip doesn’t do it.

[Michael]

TV and drive RBG LEDs based on the “average color” of the image.

Is that a question? You need a tuner if you want to do this with a TV signal, then you need a computer to process the video stream somehow.

[Michael]

The Video Experimenter makes use of some special functions on the ATmega328. For example, the analog comparator AIN0 pin on Arduino pin 6 (ATmega328 pin 12). And the external interrupt on Arduino pin 2 (ATmega328 pin 4). And the input capture pin ICP1 on Arduino pin 8 (ATmega328 pin 14).
You’ll need to study the Video Experimenter schematic to match these up with the appropriate ATmega644 pins.
Is that the kind of info you are asking about?

[Michael]

How about a link to the camera shield you are talking about? What is it?

Does it have a composite video output? Which pins does it use? These are the questions you need to ask.

When using the Video Experimenter, there’s not much CPU available to do anything else, so I’m not sure you’ll be able to do what you want…

[Michael]

If your question is “can the Video Experimenter resize a composite signal”, the answer is no. sorry. It’s very simple hardware. It simply detects the ends of scan lines and the ends of frames.

[Michael]

My original idea was to insert captioning into the video but it’s very hard to do that. You need to “overwrite” the existing CC signal, which means turning off the signal for a 0 and turning on white for 1s. I think it could be possible, but not with only the video experimenter. One could try using a 4066 analog switch to make the signal “black” (off) for the 0 bits.

[Michael]

Good question. The volume of the signal is determined by its amplitude. The reading from the ADC is a value from [0-4095] and a value in the middle of this range (2048) represents no sound. That is, the amplitude of an AC audio signal is higher the farther away from 2048. So 0 and 4095 are the loudest. The volume, then, is proportional to the distance of the ADC reading from 2048.

If you want to drive LEDs to show the volume, I would keep track of the current ADC reading in a global volatile variable, then control LEDs from withing the loop() function. Don’t do any calculation or LED control from within the ISR, as this needs to run as fast as possible.

Declare a global variable:

volatile unsigned int currentADC;

In the ISR, set this value whenever you read from the ADC. For example:

signal = AudioHacker.readADC();

currentADC = signal; // store this for access in loop()

Now in loop, calculate the distance of the current reading from silence:

unsigned int volume = abs(2048 - currentADC);

// now use this value in the range of [0, 2048] to control LEDs.

Hope that helps. The key is to do all the hard work (calculate abs, LED control) in loop, not in the ISR.

[Michael]

Hi markjosol,

This is probably an alignment problem. You need to adjust the bpos array values so that they capture the bytes. Try following the procedures described in the project for displaying the bytes on screen so you can line them up with the bpos array tick marks.

http://nootropicdesign.com/projectlab/2011/03/20/decoding-closed-captioning/

[Michael]

Please give some more detail about the problem you are experiencing.

[Michael]

This indicates that the ATMEGA is not running. I have experienced this when the solder connections associated with the crystal are bad. It’s also possible that your ATMEGA is not programmed properly (somehow).

Do you have the ability to program the chip? That is, do you have an Arduino or a USB->serial adapter or cable?

Also, where are you located? If in the US, I can easily send you another ATMEGA.

[Michael]

I think you could use an external pot connected to A2. If you make a voltage divider using another resistor, then the resistance of the pot will determine a smaller voltage range.

For example: connect the 5V source to 30K or 40K of resistance, then to the left lead of the pot. The middle lead of the pot goes to A2. The rightmost lead of the pot goes to GND. This way, the full range of the pot will provide 0V – 1V to A2 and this will allow finer adjustment.

I should have designed it this way in the first place.

[Michael]

CecilBush,

Exactly what problem are you having? The previous poster was using the board on a 32×32 matrix (for which it is not designed)…

[Author]

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