Hi all
i connected serial display in my Arduino UNO , the board is controlling heavy noise motor load through Opto isolators , some times when the AC solenoid valve clicks i am getting junk values in my serial Display (16x2) . if reset the UNO i get clear values in my display , what could be the problem , plz advice . Thanks in Advance . -prag

In my project i am using 7 segment LCD with arduino (link : http://code.google.com/p/arduino-seven-segment/ )  , in the circuit colon segment made as NC , the issue is the next number "G" segment when gets exited the colon appears , i verified my circuit the colon segment and the G segment closer to gather . i cut the colon pin from  my PCB too but still it appears , i connected the NC pin to GND or PWR rail no use . that to it appears when the system in Humid conditions in normal room temperature this issue is not coming , plz advice , i attached the picture of the same . 

I connected 1N4148 diodes to all data and control lines with respect to ground .  the issue got  sorted out 100%  . also the EMI filter i connected between the critical valve which produces the EMI . Thanks DOC .

//My problem got sorted out after i made the PCB with display soldered and processor is very close to the display .//

No still corrupting some times ,even i put 4.7k ressitors on control and data lines ,still the same issue i am facing , plz suggest some rugged idea , i pullup all the unused pins too . 

I have a similer issue with motor start up .  i am trying with two seperate power cords with class II power supply option , i will update

This i tried once i helped me , but not so much , LCD gets corrupted after some time later , i need rugged solution . 

Thanks doc,   The board is powered from computer SMPS ,  I try putting high value caps in LCD area also .  In the system whenever Relay is getting switched off and ON it is happening .  some time SMPS also gets switched off ,all well grounded  , no earth leakage

I put Coils TVS diodes, Decaps of tantalum , this issue i am seeing associated with HD44870 only .   Lot of posts they discussed this issue but no hopeful solution yet ,

   

In my project i am connecting the LCD 16x2 same in Inductive load and it gets corrupt some times when valve switches ON/OFF , i put TVS in DC bias ,Snubber at AC side nothing worked out for me . though it is a product i cant use seperate supply lines for motors , AC valves and AC/DC converter .  Any robust solution , plz suggest .  -prag

In my project i am connecting the LCD 16x2 same in Inductive load and it gets corrupt some times when valve switches ON/OFF , i put TVS in DC bias ,Snubber at AC side nothing worked out for me . though it is a product i cant use seperate supply lines for motors , AC valves and AC/DC converter .  Any robust solution , plz suggest .  -prag

  Bosses i respect all your responses , i am newbie to programming . basically biomedical guy . yes i need to react to all 16 combinations .thanks to all.  god bless.

Thanks to all your suggestions , yes CrossRoads  Robert Ji , i followed your code and finished it ,below my sample  

Code:

int messageCode = 0; // clear it out to start

void setup() {
  // initialize serial communication:
  Serial.begin(9600);  
  pinMode(6,INPUT);
  pinMode(7,INPUT);
  pinMode(8,INPUT);
  
  
}

void loop()
{
// read the 4 bits and put them in place

int bitData1 = digitalRead(6)<<2 ;
int bitData2 = digitalRead(7)<<1 ;
int bitData3 = digitalRead(8) ;

messageCode = bitData1 + bitData2 + bitData3;

switch (messageCode)
{
    case 0:
    Serial.println("i am case 0");
    break;
    case 1:
    Serial.println("i am case 1");
    break;
    case 2:
    Serial.println("i am case 2");
    break;
    case 3:
    Serial.println("i am case 3");
    break;
    case 4:
    Serial.println("i am case 4");
    break;
}

delay(1000);
}

Moderator edit: CODE TAGS

God bless..

Hi,
I am reading 4 digital pin status and writing the messages in to the 16x2 display
example : if 0000 ( all 4 pins reads 0 i am writing " NO ALARM" )
  if 0001 i am need to write " Floor 1 leak "

i used switch - case for this but it is not succeeded , can you suggest any method , thanks in advance ,
-ariesprg

here is the full working code , i missed the config address last posting,  it is generating the secs count .


void printData()
{
 long int tmp;
 Wire.beginTransmission(DS1682_ADDRESS);
 Wire.send(0);
 Wire.requestFrom(DS1682_ADDRESS, 10);
 Wire.endTransmission();

  int cnef = (Wire.receive());
  int Alarm1 = (Wire.receive());
  int Alarm2 = (Wire.receive());
  int Alarm3 = (Wire.receive());
  int Alarm4 = (Wire.receive());
  int ETC1 = (Wire.receive());
  int ETC2 = (Wire.receive());
  int ETC3 = (Wire.receive());
  int ETC4 = (Wire.receive());
  int EC1 = (Wire.receive());
  int EC2 = (Wire.receive());


tmp = ((long int) ETC4 << 24) + ((long int) ETC3<< 16) + ((long int)ETC2 << 08) + (long int) ETC1 ;
//Serial.print(tmp,DEC);
//Serial.print(":");
long int output1;
output1 = tmp/4; // to convert the quarter seconds to seconds
long int runhour = output1 / 3600; // Hour calculation
int output2 = output1%3600; // for modulo taking
int minutes = output2 /60; // for minutes
int seconds = output2 % 60 ; // for seconds
Serial.print(runhour);
Serial.print(":");
Serial.print(minutes);
Serial.print(":");
Serial.print(seconds);
}

void printData()
{
  Wire.beginTransmission(DS1682_ADDRESS);   // DS1682_ADDRESS = 0x6B
  Wire.send(0);
  Wire.requestFrom(DS1682_ADDRESS, 10);
    Wire.endTransmission();


  int Alarm1 = (Wire.receive());
  int Alarm2 = (Wire.receive());
  int Alarm3 = (Wire.receive());
  int Alarm4 = (Wire.receive());
  int ETC1 = (Wire.receive());
  int ETC2 = (Wire.receive());
  int ETC3 = (Wire.receive());
  int ETC4 = (Wire.receive());
  int EC1 = (Wire.receive());
  int EC2 = (Wire.receive());

 

  Serial.print(Alarm1);
  Serial.print("/");
  Serial.print(Alarm2);
  Serial.print("/");
  Serial.print(Alarm3);
  Serial.print(" ");
  Serial.print(Alarm4);
  Serial.print(":");
 Serial.print(ETC1);
  Serial.print(":");
  Serial.print(ETC2);
  Serial.print(":");
  Serial.print(ETC3);
  Serial.print(":");
  Serial.print(ETC4);
  Serial.println(" ");
  Serial.print(":");
 Serial.println(EC1);
  Serial.print(":");
 Serial.println(EC2);
  Serial.print(":");
}