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1  Using Arduino / General Electronics / Re: Cheap digital radio receiver WITHOUT demodulation on: May 05, 2014, 10:28:38 am
How would you pick only one station and have it's signal forwarded to other electronics? This is actually the core of my problem.
2  Using Arduino / General Electronics / Re: Cheap digital radio receiver WITHOUT demodulation on: May 04, 2014, 06:05:12 pm
Hm. An RMS or RF Detector IC would be highly useful for this, but you need to have a way of only picking up one specific radio station. How accurate does this need to be? Is it only a relative measure?

The problem with FM receiver ICs is that they are build to drive the signal to clipping, so the AGC voltage may not be good for any but the most crude measure.

http://www.ti.com/product/lmh2110

http://para.maximintegrated.com/results.mvp?fam=rf_pwr_det

http://www.analog.com/en/rfif-components/detectors/products/index.html#RMS_Detectors

http://www.ti.com/product/lmh2120

http://www.linear.com/parametric/RF_RMS_Detectors


We need to be sure to not have signal from any other station but the one we chosen.

Could you explain why AGC might not be good choice? We need accurate measurements of signal strength from that station.
3  Using Arduino / General Electronics / Re: Cheap digital radio receiver WITHOUT demodulation on: April 27, 2014, 09:11:03 am
I'm talking about frequencies usually used by commercial FM radio stations (80-110 MHz).

"Specific frequency" would seem to imply that a complete selective receiver is required and if the signal is in any way remote, a Field Strength meter is not going to "cut it".

It definitely sounds as if the TEA5767 or similar is the way to go.

Hi, if you are looking to measure signal strength, look at the radio receiver chip specs and look to see if it has a AGC or Automatic Gain Control. This pin will have a DC level on it either proportional or inversely proportional to the RF  signal strength.

Tom..... smiley

PS..http://www.voti.nl/docs/TEA5767.pdf

page 22, pin 38 Tagc, this looks like it has the agc voltage you need.
That could be it, I'll explore further. Thank you! smiley
4  Using Arduino / General Electronics / Re: Cheap digital radio receiver WITHOUT demodulation on: April 26, 2014, 10:00:11 am
Sure, that's one option. Thing is that we are trying to do this as cheap as possible and buying own components, ordering/printing PCB and soldering might not be such solution. Or I am wrong?
5  Using Arduino / General Electronics / Cheap digital radio receiver WITHOUT demodulation on: April 26, 2014, 09:02:55 am
Dear Arduino community,

In our project we need to record intensity of signal from antenna on specific frequency. Chip like Philips TEA5767 would be great, but signal must not be demodulated. Anybody have any suggestions on which chip should be used?

Best wishes,
Dario
6  Using Arduino / Interfacing w/ Software on the Computer / Re: Serial communication with php on: March 08, 2011, 05:09:21 pm
Oh. I didn't read all posts, just first one. I got serial communication with Arduino with that class.
7  Using Arduino / Interfacing w/ Software on the Computer / Re: Serial communication with php on: March 07, 2011, 03:11:37 pm
Don't bother yourself when it's already done for you:
http://code.google.com/p/php-serial/
8  Development / Other Hardware Development / Re: Arduino without ftdi chip. on: March 02, 2011, 09:46:13 am
http://www.instructables.com/id/Arduino-on-all-sorts-of-Atmels/#step1
9  Using Arduino / Programming Questions / Re: String to int on: February 06, 2011, 07:23:20 am
Thank you so much smiley
10  Using Arduino / Programming Questions / String to int on: February 05, 2011, 05:44:37 pm
How I can convert String object to integer? Thanks.
11  Using Arduino / Interfacing w/ Software on the Computer / Re: EOL and SOL, working only first time xD on: January 31, 2011, 03:29:05 pm
It's you again. smiley Thank you one more time. It's finally working.
Code:
char str[25];
int i=0;
int str_len;
int inByte;
int last_inByte;
String rezultat;
int baud = 9600;

void setup() {
  Serial.begin(baud);
}

void loop() {
  inByte = Serial.read();
  str_len=0;
  if (inByte == '!') read_serial();
}

void read_serial() {
  Serial.println ("SOL FOUND and reading");
  Serial.print("READ: !\n");
  while (inByte!= '*')
  if (Serial.available() > 0) {
    inByte = Serial.read();
    Serial.print("READ: ");
    str[str_len] = inByte;
    Serial.println(str[str_len]);
    str_len++;
  } else if (Serial.available() == 0) {
    Serial.println("EOL not available, data string invalid");
    break;
  }

  if (inByte == '*') {
    Serial.println ("EOL FOUND");
    rezultat = "";
    for (i=0;i<(str_len-1);i++) {
      rezultat += str[i];
    }
    if(rezultat == "YES") {
      Serial.println("Yeah");
    }
      Serial.print ("\n");
    }
}
12  Using Arduino / Interfacing w/ Software on the Computer / Re: EOL and SOL, working only first time xD on: January 30, 2011, 04:12:55 pm
Anyone?
13  Using Arduino / Interfacing w/ Software on the Computer / Re: EOL and SOL, working only first time xD on: January 29, 2011, 06:17:58 pm
It's inside for loop. It will loop only as much times as there are bytes waiting. I can print it, and everything is normal.
14  Using Arduino / Interfacing w/ Software on the Computer / Re: EOL and SOL, working only first time xD on: January 29, 2011, 04:49:44 pm
Bump?
15  Using Arduino / Interfacing w/ Software on the Computer / EOL and SOL, working only first time xD on: January 29, 2011, 01:56:50 pm
Code:
char str[25];
int i=0;
int str_len;
int inByte;
int last_inByte;
String rezultat;

void setup() {
  Serial.begin(9600);
}

void loop() {
  inByte = Serial.read();
  str_len=0;
  if (inByte == '!') read_serial();
}

void read_serial() {
  Serial.println ("SOL FOUND and reading");
  Serial.print("READ: !\n");
  while (inByte!= '*')
  if (Serial.available() > 0) {
    inByte = Serial.read();
    Serial.print("READ: ");
    str[str_len] = inByte;
    Serial.println(str[str_len]);
    str_len++;
  } else if (Serial.available() == 0) {
    Serial.println("EOL not available, data str invalid");
    Serial.println("$N");
    break;
  }

  if (inByte == '*') {
    Serial.println ("EOL FOUND");
    for (i=0;i<(str_len-1);i++) {
      rezultat += str[i];
    }
    if(rezultat == "YES") {
      Serial.write("Yeah");
    }
      Serial.print ("\n");
    }
}

I get 'Yeah' back only if I send !YES* as first send thing from opening serial monitor. Otherwise I don't get 'Yeah' at all. Please help.
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