Could someone explain why this statement has to be included twice for this sketch to work please?
The sketch just takes a character input from the USB port -using serial monitor- echos it back to the screen and displays its value on the leds -in decimal or hex.
Duplicate code highlighted in the code window like this....
//+++++++++++++++++++++++++++++++++++++++
countNow = SerialInVal; // +
//+++++++++++++++++++++++++++++++++++++++
Exactly the same statement is made in the code about 5 lines above it.
But without this extra one, the leds always display 0.
I am aware that countNow is destroyed by the subsequent code. I have taken this from another sketch i was using.
/* JR 15/1/2012
Take a character from USB port and write its value to HP5082-7340 LED displays.
*/
//++++ found defining these where they are used in the program saves memory
//byte state; // flag
//byte selectHex; // 0 display in decimal , 1 display in hex
//long lsn; // least ignificant nibble - lttle endian
int outPin;
int outPins[] = { 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
// array of pin numbers to which LEDs are attached
// pins 2,3,4,5 are display data bits 0,1,2,3
// pin 6 (Pwm)is blanking (1 = blank)
// pin 7 is display latch (1 = latch)
long countNow;
int SerialInVal;
void setup()
{
// loop over the pin array and set them all to output:
for (int pin = 0; pin < 10; pin++)
{
pinMode(outPins[pin], OUTPUT);
}
analogWrite(6,100); // lower value = brighter display -
// (these displays consume a lot of current)
pinMode(A5,INPUT); // Pushbutton on A5 input -
digitalWrite(A5,HIGH); // used for selecting Decimal or Hex display
Serial.begin(9600);
}// end of void setup
void loop()
{
byte selectHex = !digitalRead(A5);// read state of pushbutton and invert it
if (Serial.available())
{
SerialInVal = Serial.read();
Serial.print(SerialInVal);
Serial.print("\t"); // prints a tab
countNow = SerialInVal;
Serial.print(char(countNow));
Serial.print("\t"); // prints a tab
Serial.print(char(countNow-1));
Serial.println("");
}//end of if serial available
//+++++++++++++++++++++++++++++++++++++++++++++++++++++
countNow = SerialInVal; // +
//+++++++++++++++++++++++++++++++++++++++++++++++++++++
long lsn = countNow;
long count = countNow;
for (int pin = 7;pin < 12; pin++)
{
if (selectHex == 0)
{ //++++++++++++++++++++++++++ convert 'lsn' to bcd for decimal display
long temp = countNow / 10;
lsn = countNow - (temp * 10);
countNow = temp;
}
//+++++++++++++++++++++++++++ otherwise, just output 'lsn' in hex
// output data to display
for (int bitValue = 0; bitValue < 4;bitValue++)
{
outPin = bitValue + 2; //pin is bit position + 2
byte state = lsn & 1;
digitalWrite( outPin,state);
lsn = lsn >> 1;
}
// write to the relevent display
digitalWrite (pin, LOW); //enable display to read data
digitalWrite (pin, HIGH); //latch data
}
}//end of void loop