WS2812b

Using Arduino LEDs and Multiplexing
1

Hi!

My problem: I've written the code for using an WS2812b strip with 7 LEDs as a rpm led bar. Input is hall effect sensor. It works pretty fine, but unfortunately, the led bar doesn't restore when theres no further input and I don't get it done. So the LEDS stay on until a new Input occurs.

I'm pretty new on this subject, so pleas excuse my lack of knowledge!

Thanks

#include <Adafruit_NeoPixel.h>

const int LED_PIN = 5;
const int TACH_PIN = 2;
const int BRIGHTNESS = 100;
const int LED_COUNT = 7;
const int REDLINE = 1180;

Adafruit_NeoPixel strip = Adafruit_NeoPixel(LED_COUNT, LED_PIN, NEO_GRB + NEO_KHZ800);

bool blinkState = true;
unsigned long lastBlinkUpdate = 0;

volatile unsigned long lastIgnitionTime = 0;

void recordIgnition() {
 detachInterrupt(digitalPinToInterrupt(TACH_PIN));

 lastIgnitionTime = millis();
 
 attachInterrupt(digitalPinToInterrupt(TACH_PIN), calculateRpm, RISING);
}

void calculateRpm() {
 detachInterrupt(digitalPinToInterrupt(TACH_PIN));

 unsigned long ignitionTimeDelta = millis() - lastIgnitionTime;

 int rpm = 1000.0 / ignitionTimeDelta * 60;

 Serial.print("RPM: ");
 Serial.println(rpm);

 setRpm(rpm * 10);

 attachInterrupt(digitalPinToInterrupt(TACH_PIN), recordIgnition, RISING);
}

void setup() {
 // Open serial communications and wait for port to open:
 Serial.begin(9600);

 pinMode(TACH_PIN, INPUT);
 pinMode(5, OUTPUT);
 
 
 strip.begin();
 //strip.setBrightness(BRIGHTNESS);
 strip.show(); // Initialize all pixels to 'off'

 attachInterrupt(digitalPinToInterrupt(TACH_PIN), recordIgnition, RISING);
}


void loop() {

}
void setRpm(int rpm) {

 int rpmPerLed = REDLINE / LED_COUNT;
 

 for(int led = 0; led < LED_COUNT; led++) {

     
   if((led+1)*rpmPerLed <= rpm)
     strip.setPixelColor(led, getColor((led+1)*rpmPerLed, 1));
   else if(led*rpmPerLed < rpm && (led+1)*rpmPerLed > rpm) {
     strip.setPixelColor(led, getColor(rpm, (double)(rpm-(led)*rpmPerLed)/rpmPerLed));
   }
   else
     strip.setPixelColor(led, 0, 0, 0);  
 }
 
 strip.show();  

}


uint32_t getColor(int rpm, double intensity) {
 int red = rpm/(double)REDLINE * 255 * intensity;
 int green = (1-rpm/(double)REDLINE) * 255 * intensity;
 int blue = 0;

 return strip.Color(red, green, blue);  
}

void restore () {
 
}
2

When the input falls below a threshold clear the LEDs then update the strip.

.

3

How can i write it to the code?

4

This turns all the LEDs off:

for(int led = 0; led < LED_COUNT; led++)
{
strip.setPixelColor(led, 0, 0, 0);
}
strip.show();

.

5

thanks for your quick answer, it's seems absolutely logic, but where should i put these lines?

6

Put this code in a separate function.

Run the function whenever you want to turn off all the LEDs.

.