Grounding problem

Using Arduino Programming Questions
#1

I am working on a control panel for a monitor, using a arduino mega with a ethernet shield, the monitor is tcp commands are attached I have the program working , its basically the arduino attached to a rotary switch and sending out tcp commands depending on the position iof the switch, so I am using input_pullups and polling for lows, but it works fine when hook up to the usb port as soon as i go on the 9v power supply it just goes crazy sending comands at random almost like the boards ground is floating, is i remove the ground pin connected to the board and touch it with the outside of the usb plug it works again,

#include <SPI.h>
#include <Ethernet.h>


// mac adress (made up number)
byte mac[] = { 0x90, 0xA2, 0xDA, 0x0D, 0x9E, 0x16 };
// Static IP for arduino
byte ip[] = { 192,168,0,222 };
// Static IP for Smartview
byte bmip[] = { 192,168,0,2 };
// Client Ethernet
EthernetClient clientSmartView;
// not needed 
String code;
int i;


/**** one time running code ****/
void setup() {
//pin setup
  pinMode(30, INPUT_PULLUP);
  pinMode(31, INPUT_PULLUP);
  pinMode(32, INPUT_PULLUP);
  pinMode(13, OUTPUT); 
 
  // serial connection for troubleshoot
    Serial.begin(9600);
    Serial.println("Serial connection established");
  delay(500);
    Serial.println("Port set at 9600 bps");
  delay(500);
// Connection Ethernet
  Ethernet.begin(mac,ip);
  delay(500);
  Serial.println("IP connection in progress ...");
  delay(1000);
  //if connected say so otherwise say failed
   if(clientSmartView.connect(bmip, 9992 )) {
   Serial.println("connection established");
   }
  else {
       Serial.println("Connection failed");
       }
  }

//main progran loop
void loop(){
//pin declare  
  
  int sensorVal1 = digitalRead(30);
  int sensorVal2 = digitalRead(31);
  int sensorVal3 = digitalRead(32);

 if (sensorVal1 != HIGH && i != 6) {
    delay(100);
    //Serial.println("pin 30");
    //Serial.println(i);
    MONAPIC();
    //int i = 6;
  } 
  if (sensorVal2 != HIGH && i != 7) {
   delay(100);
    
    //Serial.println("pin 31");
    //Serial.println(i);
    MONAVEC();
   // int i = 7;
  }
if (sensorVal3 != HIGH && i != 8) {
    delay(100);
   
    //Serial.println("pin 32");
    //Serial.println(i);
    MONAWAV();

   // int i = 8;
  } 
}
//subroutines
int MONAPIC()//monitor A picture
{
clientSmartView.connect(bmip, 9992);
delay(100);
if (clientSmartView.connected()) {
  clientSmartView.println("MONITOR A: ");
  clientSmartView.println("ScopeMode: Picture");
  clientSmartView.write(0x0A);
  clientSmartView.stop();
  i=6;
 }
return i;
}
int MONAVEC()//monitor A vector
{
clientSmartView.connect(bmip, 9992);
delay(100);
if (clientSmartView.connected()) {
  clientSmartView.println("MONITOR A: ");
  clientSmartView.println("ScopeMode: Vector100");
  clientSmartView.write(0x0A);
  clientSmartView.stop();
  i=7;
 }
return i;
}
int MONAWAV()//monitor A waveform
{
clientSmartView.connect(bmip, 9992);
delay(100);
if (clientSmartView.connected()) {
  clientSmartView.println("MONITOR A: ");
  clientSmartView.println("ScopeMode: WaveformLuma");
  clientSmartView.write(0x0A);
  clientSmartView.stop();
  i=8;
 }
return i;
}

SmartView Manual.pdf (2.78 MB)

#2

as i go on the 9v power supply

What kind of 9V power supply? Is it red?

#3

apparently i failed to read the reviews,

#4

I can't comment on the suitability of that power supply, although the 650mA rating is pretty low for an ethernet shield toting Arduino.

I can comment on your code, though.

 if (sensorVal1 != HIGH && i != 6) {

The name sensorVal1 suggests to me that the variable contains a sensor value, and that it is one of many. An array might be better, but since there are only three, it's not really necessary.

The name i suggests that this is a throwaway when done variable, like a loop index. It is a horrid name for a global variable.

// not needed 
String code;

Then why not delete it, and make your program smaller?

   if(clientSmartView.connect(bmip, 9992 )) {
   Serial.println("connection established");
   }
  else {
       Serial.println("Connection failed");
       }
  }

Consistent
indenting
is
preferred.

Use Tools + Auto Format.

There are far more delay()s in setup() than are needed. In reality, NONE is the correct number to use.

    MONAPIC();

By convention, all capital letter names are reserved for constants. Functions are hardly constants. A function name should describe what the function does, like digitalRead(), pinMode(), Ehternet.begin(), etc. MONAPIC doesn't suggest anything to me. Looks like it could just as well have been called Jt52lhM().

#5

Yes a co-worker who programs PIC chips as a hobby pointed out all my programming faux paus, I put it togheter from other examples and from what i remember from school (15 yrs ago), at any rate changing the power supply did the trick, I guess there is no regulation on the board itself.

#6

claudio_araoz:
Yes a co-worker who programs PIC chips as a hobby pointed out all my programming faux paus, I put it togheter from other examples and from what i remember from school (15 yrs ago), at any rate changing the power supply did the trick, I guess there is no regulation on the board itself.

There is in fact a 5V regulator on the board. There has to be, since you can't run AVR chips higher than about 5.5V. It's just that your power supply was a piece of junk and the regulator couldn't handle it.

#7