Ethernet shield sensitive digital input help

[Daz23079]

Need help i have just set up a arduino mega with ethernet shield to send twitter with four digital inputs but it keeps looping as soon as i touch a wire going in to one of the digital inputs or if i connect a digital in to an empty bread board it just seems realy sensitive is there a way around this or have i got a dodgy ethernet shield ?

[adafruit_support_bill]

Do you have pull-up or pull-down resistors on your digital inputs? Does your code handle debouncing?

See Tutorial #5 for details on these topics. http://www.ladyada.net/learn/arduino/lesson5.html

[Daz23079]

Sorry i am new to this but the pins are set high

[Daz23079]

This is the sketch i am using i wish to use basic relays to switch the inputs 2,3,4,5 can you help or modify the sketch please thanks



[Edit - moderator - use code button to submit large blocks of code]

Code: Select all

// necessary libraries
#if defined(ARDUINO) && ARDUINO > 18   // If using Arduino 0019 or later, include SPI.h
#include <SPI.h>
#endif
#include <Ethernet.h>
#include <EthernetDNS.h>
#include <Twitter.h>

// our event messages
char b1[]="one";
char b2[]="two";
char b3[]="three";
char b4[]="four";

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; // create MAC address for ethernet shield
byte ip[] = { }; // choose your own IP for ethernet shield
byte gateway[] = {  }; // your network gateway
byte subnet[] = { 255, 255, 255, 0 }; // your network subnet

// Your Token to Tweet (get it from http://arduino-tweet.appspot.com/)
Twitter twitter("aaaaaaaa");
// replace aaaaaaa with your token
// ***********************************************************************************************

void setup()
{
  delay(5000);
  Ethernet.begin(mac, ip, gateway, subnet);
  Serial.begin(9600);
  pinMode(2, INPUT);
  pinMode(3, INPUT);
  pinMode(4, INPUT);
  pinMode(5, INPUT);
}
 
void tweet(char msg[])
{
  Serial.println("connecting ...");
  if (twitter.post(msg)) {
    int status = twitter.wait(&Serial);
    if (status == 200) {
      Serial.println("OK.");
    } else {
      Serial.print("failed : code ");
      Serial.println(status);
    }
  } else {
    Serial.println("connection failed.");
  }
}

void loop()
{
  if (digitalRead(2)==HIGH)
  {
    tweet(b1);
    delay(2000);
  }
  if (digitalRead(3)==HIGH)
  {
    tweet(b2);
    delay(2000);
  }
  if (digitalRead(4)==HIGH)
  {
    tweet(b3);
    delay(2000);   
  }
  if (digitalRead(5)==HIGH)
  {
    tweet(b4);
    delay(2000);   
  }
}

[adafruit_support_bill]

the pins are set high

How?

i wish to use basic relays to switch the inputs 2,3,4,5

Relays are like switches in many ways. First, you need a pullup or pulldown resistor to keep the pin from 'floating'. Second, the contacts may 'bounce' as they close. This can appear to your sketch as a series of rapid opening an closing of the contacts.

Read through Tutorial #5. All the basic concepts regarding button/switch input apply to relays as well.http://www.ladyada.net/learn/arduino/lesson5.html