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Topic: storing data from sensors (Read 1 time) previous topic - next topic

victorfb

Hi, I am making a robot that uses 3 ultrasonic sensors to navigate through a path. I want to get the values that the sensors provide for a given path and store them somewhere. How can I do that. To read all three sensors I use an array already is there a way that I can get all the arrays and store on a matrix or something? Here is the code of how I read the sensors.

Code: [Select]
int ping(int j) {
  int duration, distance;
  pinMode (trigPin[j], OUTPUT);
  pinMode (echoPin[j], INPUT);
  digitalWrite(trigPin[j], LOW);
  digitalWrite(trigPin[j], HIGH);
  duration = pulseIn(echoPin[j], HIGH);
  distance = (duration/2) / 29.1;
  return distance;
}
void loop(){
  int minimum, Position, distance[3], j;
  for (i=0; i<3; i++){
  distance[i]=ping(i);
  delay (35);
 
  }

PaulS

Quote
To read all three sensors I use an array already is there a way that I can get all the arrays and store on a matrix or something? Here is the code of how I read the sensors.

If you mean all one of the arrays, yes. If the something in "store on a matrix or something" includes an SD card, yes. Storing the data on a LED matrix seems kind of silly.

xvjeko


Hi, I am making a robot that uses 3 ultrasonic sensors to navigate through a path. I want to get the values that the sensors provide for a given path and store them somewhere. How can I do that. To read all three sensors I use an array already is there a way that I can get all the arrays and store on a matrix or something? Here is the code of how I read the sensors.

Code: [Select]
int ping(int j) {
  int duration, distance;
  pinMode (trigPin[j], OUTPUT);
  pinMode (echoPin[j], INPUT);
  digitalWrite(trigPin[j], LOW);
  digitalWrite(trigPin[j], HIGH);
  duration = pulseIn(echoPin[j], HIGH);
  distance = (duration/2) / 29.1;
  return distance;
}
void loop(){
  int minimum, Position, distance[3], j;
  for (i=0; i<3; i++){
  distance[i]=ping(i);
  delay (35);
 
  }



at first glance i doubt the code would read values from the sensors

victorfb

Quote
If you mean all one of the arrays, yes. If the something in "store on a matrix or something" includes an SD card, yes. Storing the data on a LED matrix seems kind of silly.

I never said that I were using a any type of matrix. I am just wondering how can I get all the arrays and store their values somewhere and how can I do that.

Quote
at first glance i doubt the code would read values from the sensors

this function read all the sensors. I am using 3 HC-SR04 sensors that use 2 pins to make the readings

xvjeko

Quote
at first glance i doubt the code would read values from the sensors

Quote

this function read all the sensors. I am using 3 HC-SR04 sensors that use 2 pins to make the readings


Ok if you tried it, then sry....
Because my HC-SR04 gave me a headache, and i ended up doing something more complex than you wrote...  :smiley-mr-green:

victorfb

Quote
Ok if you tried it, then sry....
Because my HC-SR04 gave me a headache, and i ended up doing something more complex than you wrote... 

Yeah, they gave me some headaches too, but I was able to figure it out now they read fine.

NickPyner


I am just wondering how can I get all the arrays and store their values somewhere and how can I do that.
this function read all the sensors.


If you can make the numbers, you can store them. It really is as simple as that.
I may be biased because my  Arduino came with a slot, but I think using an SD card is the obvious choice, if only because you are unlikely to have any problems with capacity.

Retrieving the numbers is another matter, but I imagine it is just a matter of how you read a single CSV file.

PeterH


is there a way that I can get all the arrays and store on a matrix or something?


Two important questions are:

  • How many values do you want to store?

  • What are you going to do with the stored values?



The answers to these questions will determine what options are sensible for storing them.
I only provide help via the forum - please do not contact me for private consultancy.

victorfb

Quote
Two important questions are:
How many values do you want to store?
What are you going to do with the stored values?

The answers to these questions will determine what options are sensible for storing them.

I want to get this information and transmit wirelessly using Xbee's

PaulS

Quote
I want to get this information and transmit wirelessly using Xbee's

You already have an array that contains the data. Why do you need to copy it somewhere else?

Transmitting data wirelessly or wired is exactly the same from the Arduino's point of view. It doesn't know that the pins it is wiggling are connected to a USB to serial chip or to an XBee via a shield. The pins are wiggled exactly the same way. Sometimes it matters which pins are wiggled, and whether the HardwareSerial class or the SoftwareSerial class is doing the wiggling.

victorfb

Quote
You already have an array that contains the data. Why do you need to copy it somewhere else?

I don't want to send just one array, I am getting a lot of information from the sensors and I want to send all of it

PaulS

Quote
I don't want to send just one array, I am getting a lot of information from the sensors and I want to send all of it

You get some data. You store the data in an array as you get it. When you have all of it, you start over getting more.

Once you have an array full of data, send that array, and then start over.

victorfb

Quote
You get some data. You store the data in an array as you get it. When you have all of it, you start over getting more.

Once you have an array full of data, send that array, and then start over.

I don't know if this would work in my case because I want the car to go all the way in the path and then send the data. And then I want another car to read this data and go through the same path, and I don't think the arduino would have memory enough to store all this data.
I bought a sd shield to store all these arrays in a sd card, but I am having difficulties in doing so. This is the code that the arduino IDE has as example to read and write something in a card
Code: [Select]
/*
  SD card read/write

This example shows how to read and write data to and from an SD card file
The circuit:
* SD card attached to SPI bus as follows:
** MOSI - pin 11
** MISO - pin 12
** CLK - pin 13
** CS - pin 4

created   Nov 2010
by David A. Mellis
modified 9 Apr 2012
by Tom Igoe

This example code is in the public domain.

*/

#include <SD.h>

File myFile;

void setup()
{
// Open serial communications and wait for port to open:
  Serial.begin(9600);
   while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }


  Serial.print("Initializing SD card...");
  // On the Ethernet Shield, CS is pin 4. It's set as an output by default.
  // Note that even if it's not used as the CS pin, the hardware SS pin
  // (10 on most Arduino boards, 53 on the Mega) must be left as an output
  // or the SD library functions will not work.
   pinMode(10, OUTPUT);
   
  if (!SD.begin(4)) {
    Serial.println("initialization failed!");
    return;
  }
  Serial.println("initialization done.");
 
  // open the file. note that only one file can be open at a time,
  // so you have to close this one before opening another.
  myFile = SD.open("test.txt", FILE_WRITE);
 
  // if the file opened okay, write to it:
  if (myFile) {
    Serial.print("Writing to test.txt...");
    myFile.println("testing 1, 2, 3.");
// close the file:
    myFile.close();
    Serial.println("done.");
  } else {
    // if the file didn't open, print an error:
    Serial.println("error opening test.txt");
  }
 
  // re-open the file for reading:
  myFile = SD.open("test.txt");
  if (myFile) {
    Serial.println("test.txt:");
   
    // read from the file until there's nothing else in it:
    while (myFile.available()) {
    Serial.write(myFile.read());
    }
    // close the file:
    myFile.close();
  } else {
  // if the file didn't open, print an error:
    Serial.println("error opening test.txt");
  }
}

void loop()
{
// nothing happens after setup
}

I ran it and works fine. but how where do I put my code so it stores the array that I am generating?
Again this is how I am getting the values from the sensors
Code: [Select]
int ping(int j) {
  int duration, distance;
  pinMode (trigPin[j], OUTPUT);
  pinMode (echoPin[j], INPUT);
  digitalWrite(trigPin[j], LOW);
  digitalWrite(trigPin[j], HIGH);
  duration = pulseIn(echoPin[j], HIGH);
  distance = (duration/2) / 29.1;
  return distance;
}
void loop(){
  int minimum, Position, distance[3], j;
  for (i=0; i<3; i++){
  distance[i]=ping(i);
  delay (35);
 
  }

PeterH


Quote
Two important questions are:
How many values do you want to store?
What are you going to do with the stored values?

The answers to these questions will determine what options are sensible for storing them.

I want to get this information and transmit wirelessly using Xbee's


You didn't answer the first question.
I only provide help via the forum - please do not contact me for private consultancy.

victorfb

Quote
You didn't answer the first question.

I don't know how many values will be stored, it will depend on how long is the path that the car that has the sensors will pass. I imagine will be a lot of values since I have a sensor reading every 35ms

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