problems with dxm reception

Forum 2005-2010 (read only) Software Syntax & Programs
1

Hi

arduino only receives the first 24channels of the dxm data.
please help me to find the failure:

i used the following code to receive dmx:

#define myubbr (16000000L/16/250000-1)

volatile int DMXChannel = 0;
static unsigned char DMX[512];

ISR(USART_RX_vect) {
  char temp,temp1;
  temp1 = UCSR0A;
  temp = UDR0&0xFF;
  if ((temp1 & (1<<FE0))||temp1 & (1<<DOR0)) //Break
  {
    DMXChannel = 0;
    return;
  }
  else if (DMXChannel<(char)25)
  {
    digitalWrite(ledPin,HIGH);
    DMX[DMXChannel++]=temp&0xFF;
  }
  digitalWrite(ledPin,LOW);
}

void setup() {  );
  delay(100);
  UBRR0H = (unsigned char)(myubbr>>8);
  UBRR0L = (unsigned char)myubbr;
  UCSR0B |= ((1<<RXEN0)|(1<<RXCIE0));//Enable Receiver and Interrupt RX
  UCSR0C |= (3<<UCSZ00);//N81

this is the code regarding the dmx reception.

anyone a suggestion why i can only receiv the first 24 channels?

2

[code]  else if (DMXChannel<(char)25)[/code]
DMXChannel is an int that is being compared to an integer value that you have cast to a char. Why?

void setup() {  );
  delay(100);
  UBRR0H = (unsigned char)(myubbr>>8);
  UBRR0L = (unsigned char)myubbr;
  UCSR0B |= ((1<<RXEN0)|(1<<RXCIE0));//Enable Receiver and Interrupt RX
  UCSR0C |= (3<<UCSZ00);//N81

What's with the random code outside a function?

3

thank you for pointing me in the right direction.
i must have been blind.

changing

else if (DMXChannel<(char)25)

to

else if (DMXChannel<512)

solved the problem