Using serial communication without pc

You're a bit confusing, serial communication means sending data on a single communication channel bit by bit, hence it's name. Usb also does serial communication as rs232 but at a way faster rates and using different protocols. You want your robot to be controlled from a computer or from a remote control? If you want to get rid of your arduino's and just use the microcontrollers (atmega328), well you can either way (pc or remote), you just have to adapt the software on both microcontrollers and setup the fuses for external clock to use without arduino boards. Here's a useful link Arduino - ArduinoToBreadboard

Thank you sir, the link was helpful. I wanted to use my arduino as remote control and receiver on the car which works without a computer. I want my robot to be controlled by a remote control. Sorry for the confusion with the serial communication, I just wanted to tell about the Serial.print and Serial.read commands.

Thank you sir, the link was helpful. I wanted to use my arduino as remote control and receiver on the car which works without a computer. I want my robot to be controlled by a remote control. Sorry for the confusion with the serial communication, I just wanted to tell about the Serial.print and Serial.read commands.

There are many considerations to take in account:

-instead of using "serial.print" which is a display command, try using "serial.write" to transmit data (http://arduino.cc/en/Serial/Print#.UyoIPIXPsvw)

-have you used the virtualwire library?

-it's well known that cheap 434MHz rf modules are "what you pay is what you get" so you might aswell get delays and corrupted transmission from them even with the increase of the length of the antenna, when you have obstacles and interference. Don't expect large distances operations, these modules work in amplitude shift keying for low performance applications (http://en.wikipedia.org/wiki/Amplitude-shift_keying)

Hi,

Sorry, I'm quite new to the arduino( and electronic) platform, so apologies in advance if my queries seem silly.

But does that mean i would need to replace the serial.print commands with serial.write or since I would no longer require the laptop interface, can I just get rid of all the serial.print commands in my code?

I am working on getting rid of my laptop interface and just uploading the code onto my arduino board. unfortunately, even after getting rid of all the serial.print commands while retaining all the other essential parts of the code, I dont seem to have it working without the usb to pc connection.

May I know what I'm doing wrong? Am I expected to ADD certain code now ( like the serial.write command) into my code now?

Many thanks for any help with regard to me query!

Hi elizabethmath

I think we need to know a little bit more about what you are trying to do with your Arduino program.

A block diagram and/or your code would be very helpful.

Neil

Please provide the sketch your using,

There is no reason you need the PC connected to run you sketch but there may be something in you code that will help us to help you

Hi,

Thank you so very much for taking time out to assist me with this. I really appreciate the help!

Hi,

Thank you so very much for taking time out to assist me with this. I really appreciate the help!

the code i'm using is found on the adarfuit fingerprint repository library :

#include <Adafruit_Fingerprint.h>

#include <SoftwareSerial.h>

int getFingerprintIDez();

// pin #2 is IN from sensor (GREEN wire)

// pin #3 is OUT from arduino  (WHITE wire)

SoftwareSerial mySerial(2, 3); 

Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial);

On Leonardo/Micro or others with hardware serial, use those! #0 is green wire, #1 is white

//Adafruit_Fingerprint finger = Adafruit_Fingerprint(&Serial1);

void setup() 

{

  while (!Serial);  // For Yun/Leo/Micro/Zero/...

  Serial.begin(9600);

  Serial.println("Adafruit finger detect test");

  // set the data rate for the sensor serial port

  finger.begin(57600);

  if (finger.verifyPassword()) {

    Serial.println("Found fingerprint sensor!");

  } else {

    Serial.println("Did not find fingerprint sensor :(");

    while (1);

  }

  Serial.println("Waiting for valid finger...");

}

void loop()                     // run over and over again

{

  getFingerprintIDez();

  delay(50);            //don't ned to run this at full speed.

}

uint8_t getFingerprintID() {

  uint8_t p = finger.getImage();

  switch (p) {

    case FINGERPRINT_OK:

      Serial.println("Image taken");

      break;

    case FINGERPRINT_NOFINGER:

      Serial.println("No finger detected");

      return p;

    case FINGERPRINT_PACKETRECIEVEERR:

      Serial.println("Communication error");

      return p;

    case FINGERPRINT_IMAGEFAIL:

      Serial.println("Imaging error");

      return p;

    default:

      Serial.println("Unknown error");

      return p;

  }

  // OK success!

  p = finger.image2Tz();

  switch (p) {

    case FINGERPRINT_OK:

      Serial.println("Image converted");

      break;

    case FINGERPRINT_IMAGEMESS:

      Serial.println("Image too messy");

      return p;

    case FINGERPRINT_PACKETRECIEVEERR:

      Serial.println("Communication error");

      return p;

    case FINGERPRINT_FEATUREFAIL:

      Serial.println("Could not find fingerprint features");

      return p;

    case FINGERPRINT_INVALIDIMAGE:

      Serial.println("Could not find fingerprint features");

      return p;

    default:

      Serial.println("Unknown error");

      return p;

  }

  // OK converted!

  p = finger.fingerFastSearch();

  if (p == FINGERPRINT_OK) {

    Serial.println("Found a print match!");

  } else if (p == FINGERPRINT_PACKETRECIEVEERR) {

    Serial.println("Communication error");

    return p;

  } else if (p == FINGERPRINT_NOTFOUND) {

    Serial.println("Did not find a match");

    return p;

  } else {

    Serial.println("Unknown error");

    return p;

  }  

  // found a match!

  Serial.print("Found ID #"); Serial.print(finger.fingerID);

  Serial.print(" with confidence of "); Serial.println(finger.confidence);

}

// returns -1 if failed, otherwise returns ID #

int getFingerprintIDez() {

  uint8_t p = finger.getImage();

  if (p != FINGERPRINT_OK)  return -1;

  p = finger.image2Tz();

  if (p != FINGERPRINT_OK)  return -1;

  p = finger.fingerFastSearch();

  if (p != FINGERPRINT_OK)  return -1;

  // found a match!

  Serial.print("Found ID #"); Serial.print(finger.fingerID);

  Serial.print(" with confidence of "); Serial.println(finger.confidence);

  return finger.fingerID;

#include <Adafruit_Fingerprint.h>

#include <SoftwareSerial.h>

int getFingerprintIDez();

// pin #2 is IN from sensor (GREEN wire)

// pin #3 is OUT from arduino  (WHITE wire)

SoftwareSerial mySerial(2, 3);

Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial);

On Leonardo/Micro or others with hardware serial, use those! #0 is green wire, #1 is white

//Adafruit_Fingerprint finger = Adafruit_Fingerprint(&Serial1);

void setup() 

{

  while (!Serial);  // For Yun/Leo/Micro/Zero/...

  Serial.begin(9600);

  Serial.println("Adafruit finger detect test");

  // set the data rate for the sensor serial port

  finger.begin(57600);

  if (finger.verifyPassword()) {

    Serial.println("Found fingerprint sensor!");

  } else {

    Serial.println("Did not find fingerprint sensor :(");

    while (1);

  }

  Serial.println("Waiting for valid finger...");

}

void loop()                     // run over and over again

{

  getFingerprintIDez();

  delay(50);            //don't ned to run this at full speed.

}

uint8_t getFingerprintID() {

  uint8_t p = finger.getImage();

  switch (p) {

    case FINGERPRINT_OK:

      Serial.println("Image taken");

      break;

    case FINGERPRINT_NOFINGER:

      Serial.println("No finger detected");

      return p;

    case FINGERPRINT_PACKETRECIEVEERR:

      Serial.println("Communication error");

      return p;

    case FINGERPRINT_IMAGEFAIL:

      Serial.println("Imaging error");

      return p;

    default:

      Serial.println("Unknown error");

      return p;

  }

  // OK success!

  p = finger.image2Tz();

  switch (p) {

    case FINGERPRINT_OK:

      Serial.println("Image converted");

      break;

    case FINGERPRINT_IMAGEMESS:

      Serial.println("Image too messy");

      return p;

    case FINGERPRINT_PACKETRECIEVEERR:

      Serial.println("Communication error");

      return p;

    case FINGERPRINT_FEATUREFAIL:

      Serial.println("Could not find fingerprint features");

      return p;

    case FINGERPRINT_INVALIDIMAGE:

      Serial.println("Could not find fingerprint features");

      return p;

    default:

      Serial.println("Unknown error");

      return p;

  }

  // OK converted!

  p = finger.fingerFastSearch();

  if (p == FINGERPRINT_OK) {

    Serial.println("Found a print match!");

  } else if (p == FINGERPRINT_PACKETRECIEVEERR) {

    Serial.println("Communication error");

    return p;

  } else if (p == FINGERPRINT_NOTFOUND) {

    Serial.println("Did not find a match");

    return p;

  } else {

    Serial.println("Unknown error");

    return p;

  }  

  // found a match!

  Serial.print("Found ID #"); Serial.print(finger.fingerID);

  Serial.print(" with confidence of "); Serial.println(finger.confidence);

}

// returns -1 if failed, otherwise returns ID #

int getFingerprintIDez() {

  uint8_t p = finger.getImage();

  if (p != FINGERPRINT_OK)  return -1;

  p = finger.image2Tz();

  if (p != FINGERPRINT_OK)  return -1;

  p = finger.fingerFastSearch();

  if (p != FINGERPRINT_OK)  return -1;

  // found a match!

  Serial.print("Found ID #"); Serial.print(finger.fingerID);

  Serial.print(" with confidence of "); Serial.println(finger.confidence);

  return finger.fingerID;

It should make no difference if the PC is connected or not, the hardware serial (Pin 0 and 1) will still flicker one of the LEDs as it will still transmit to the USB controller. it just won't receive serial data from the PC or ultimately send serial to the PC from the USB interface. For the fingerprint reader you're using a software serial on separate pins (2, 3)

What is my first thought is that the power is affecting it. When the PC is connected your providing 5V nominal through the USB port and everything is working from this

What is the battery voltage and where are you connecting it, you should be connecting something like 6-9 V on the barrel connector, 5V via a USB lead or the 5V pin on the headers. or 6-9V via the header pin marked Vin.

Please provide this info

Hi Mr. Oakes,

The problem is that neither of the led lights signalling Rx and Tx communication flicker when the system is not connected to a laptop.

I think thats the part I'm having most trouble figuring out.

With the voltage supply, I have tried both the barrel connector for the 9v battery as well as connecting the 9v battery supply into the Vin pin. I get the same response from both.

I also tried checking to see if the battery was supplying enough voltage as per the fingerprint scanner requirement.

Using a multi meter, I established that the fingerprint scanner was indeed receiving between its allowed range of 3.66- 6 V.

It was on these grounds that I ruled out a problem with the electrical set up.

What are your thoughts?

Do you think it could still be a problem with the power supply?