Add for loop in if statements

Using Arduino Programming Questions
1

I am working on a project about controlling led bands with brainwave values. When I add the led's program into the if, the program goes into a dead loop.

void loop() 
{
  setColor();
  read_serial_data();
  if(attention>10&attention<50){
      for (int i=0; i < NUMPIXELS; i++) {
    // pixels.Color takes RGB values, from 0,0,0 up to 255,255,255
    pixels.setPixelColor(i, pixels.Color(redColor, greenColor, blueColor));

    // This sends the updated pixel color to the hardware.
    pixels.show();

    // Delay for a period of time (in milliseconds).
    delay(delayval);
  }
  }


}

How should I go about changing this code?
Thanks

2 
void loop(){
  setColor();
  read_serial_data();
  if (attention > 10 & attention < 50) {
    for (int i = 0; i < NUMPIXELS; i++) {
      pixels.setPixelColor(i, pixels.Color(redColor, greenColor, blueColor));
    }
    pixels.show();
    delay(delayval);
  }
}
3 
if(attention>10&attention<50)

& does a bitwise AND
&& does a logical AND

I suspect that you are using the wrong one

4

What does that look like?
What does setColor() do?
How long is 'delayval'?

5

Hi,johnwasser

This is my entire program. The program stops when the if statement is met and the serial monitor no longer prints any data.


#include <Adafruit_NeoPixel.h>

#define PIN 7         // input pin Neopixel is attached to

#define NUMPIXELS      12 // number of neopixels in strip

Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);

int delayval = 100; // timing delay in milliseconds

int redColor = 0;
int greenColor = 0;
int blueColor = 0;
#define BAUDRATE 57600
#define DEBUGOUTPUT 0


int   generatedChecksum = 0;
byte  checksum = 0; 


byte  payloadLength = 0;
byte  payloadData[32] = {0};


byte signalquality = 0;
byte attention = 0;    
byte meditation = 0;   


void setup() 
{
  Serial.begin(BAUDRATE); 
  pixels.begin();
}


byte ReadOneByte() 
{
  int ByteRead;
  while(!Serial.available());
  ByteRead = Serial.read();
  return ByteRead;
}

//读取串口数据
void read_serial_data()
{
    
    if(ReadOneByte() == 0xAA)
    {
      if(ReadOneByte() == 0xAA)
      {
        payloadLength = ReadOneByte();
        if(payloadLength == 0x20)
        {
          generatedChecksum = 0;       
          for(int i = 0; i < payloadLength; i++)
          {  
            payloadData[i] = ReadOneByte();
            generatedChecksum += payloadData[i];
          }         
          checksum = ReadOneByte();
          
          generatedChecksum = (~generatedChecksum)&0xff;       
          
          if(checksum == generatedChecksum)
          {    
            signalquality = 0;
            attention = 0;    
            
            signalquality = payloadData[1]; 
            attention = payloadData[29];
            meditation = payloadData[31];
            #if !DEBUGOUTPUT         
            
            Serial.print("SignalQuality: ");
            Serial.print(signalquality, DEC);
            
            Serial.print("Attation: ");
            Serial.print(attention, DEC);
            
            Serial.print("Meditation: ");
            Serial.print(meditation, DEC);
            
            Serial.print("\n");       
            #endif              
          } 
        } 
      }
    }
}


void loop(){
  setColor();
  read_serial_data();
  if (attention > 10 & attention < 50) {
    for (int i = 0; i < NUMPIXELS; i++) {
      pixels.setPixelColor(i, pixels.Color(redColor, greenColor, blueColor));
    }
    pixels.show();
    delay(delayval);
  }
}

void setColor(){
  redColor = random(0, 255);
  greenColor = random(0,255);
  blueColor = random(0, 255);
}
6

Did you do as suggested in post #3?

Put a serial print at the bottom of loop() and perhaps elsewhere to see if it actually "stops".

7

I have tried to replace for loop with serial print，like this：

if (attention > 10 & attention < 50) {
  serial.print("test done")
  }

it works. So I guess the problem is that the for loop is used in the if statement

8

I see that you still have a single & in that if statement. Is that deliberate ?

9

You still have this mistake:

Change that line to:
if (attention > 10 && attention < 50) {

10

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.