Help with Stair Lighting using HC-SR04 sensor and WS2812 LED Strip

Other Hardware LEDs and Multiplexing
1

Hi All
Excuse my naivete in this as I am very new to Arduino and the programming of. I am trying to put together a project for stair lighting triggered by a ultrasonic sensor at the bottom of the stairs and turned off by an ultrasonic sensor at the top of the stairs. I am using an WS2812 LED strip and have the lights travel up the stairs when going up and down when going down. I'm sure this is a project many of you have seen. I have searched the net and youtube and have found many examples of this project, none that I can find using the HC-SR04 sensor. I have managed to cobble together a code which works fine in one direction but am now stumped as how to get it to work the other way.
I would also like to add an LDR to the project so it is only active at night. If any of you can point me in the right direction I would be really grateful. I have attached the code so you can see where I am at.

#include <FastLED.h>
#define trigPin_up 2
#define echoPin_up 3
#define trigPin_down 4
#define echoPin_down 5
#define LED_PIN     7
#define NUM_LEDS    13
CRGB leds[NUM_LEDS];

  int tOn = 400; //LED On delay
  int tOff = 750; //LED Off delay
  int del = 0; //Delay after action (used for debugging - set to 500-1000 to introduce a delay between each action)
 
 
void setup() {

    //Set Serial
  Serial.begin(9600);
  Serial.println("");
  Serial.println("Activated");
  delay(del);
 
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);
  
  pinMode(trigPin_up, OUTPUT);
  pinMode(echoPin_up, INPUT);
  pinMode(trigPin_down, OUTPUT);
  pinMode(echoPin_down, INPUT);
}
 void loop() {
   short duration, distance;
  digitalWrite(trigPin_up, LOW); 
  delayMicroseconds(2);
  digitalWrite(trigPin_up, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin_up, LOW);
  duration = pulseIn(echoPin_up, HIGH);
  distance = (duration/2) / 35.1;
 

  if (distance <= 50) {
  leds[0] = CRGB(255, 225, 255);
  FastLED.show();
  delay(100);  
  leds[1] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[2] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[3] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[4] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[5] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[6] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[7] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[8] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[9] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[10] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[11] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[12] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[13] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  }
  
{    short duration, distance;
  digitalWrite(trigPin_down, LOW); 
  delayMicroseconds(2);
  digitalWrite(trigPin_down, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin_down, LOW);
  duration = pulseIn(echoPin_down, HIGH);
  distance = (duration/2) / 35.1;
 

  if (distance <= 50) {
  leds[0] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);  
  leds[1] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[2] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[3] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[4] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[5] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[6] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[7] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[8] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[9] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[10] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[11] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[12] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[13] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  }
} 
}

This is just a test code, the final project will have around 200 LEDS.

Many thanks

2

The code you showed has a duplicate part.

Your basic idea is interesting. However, using two sensors far from each other is not good solution, because of wiring and powering. I suggest using only one motion sensor instead of two ultrasonic sensors.

3

Hi, the problem with using only 1 sensor is I'll only get control in 1 direction. I need to have the lights turn on and flow up if I'm going up the stairs and turn off once I reach the top and turn on and flow down the stairs if I'm going down. I'm using a 5V 60A PSU to power everything so I don't think power will be an issue.

What part of the code is duplicated?

Thanks

4

This part

 short duration, distance;
  digitalWrite(trigPin_up, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin_up, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin_up, LOW);
  duration = pulseIn(echoPin_up, HIGH);
  distance = (duration/2) / 35.1;
 

  if (distance <= 50) {
  leds[0] = CRGB(255, 225, 255);
  FastLED.show();
  delay(100); 
  leds[1] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[2] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[3] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[4] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[5] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[6] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[7] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[8] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[9] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[10] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[11] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[12] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[13] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  }
5

So, You can use two ultrasonic sensors or two motion sensors.
Both sensors are positioned at the same position, in the middle of stair. Two sensor point to two different directions

6

I've managed to put together a code that now works in both directions but it is intermittent in working. Sometimes the sensors work first time, other times you need to block them for a couple of seconds. Also you can't trigger either sensor straight after walking past it. here is the code so far

#include <FastLED.h>
#define trigPin_up 2
#define echoPin_up 3
#define trigPin_down 4
#define echoPin_down 5
#define LED_PIN     7
#define NUM_LEDS    13
CRGB leds[NUM_LEDS];

  
 
void setup() {

    //Set Serial
  Serial.begin(9600);

 
  

 
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);
  
  pinMode(trigPin_up, OUTPUT);
  pinMode(echoPin_up, INPUT);
  pinMode(trigPin_down, OUTPUT);
  pinMode(echoPin_down, INPUT); 
  
  
}
 void loop(){
 if (trigPin_up, HIGH && trigPin_down, LOW);
 {
   short duration, distance;
  digitalWrite(trigPin_up, LOW); 
  delayMicroseconds(2);
  digitalWrite(trigPin_up, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin_up, LOW);
  duration = pulseIn(echoPin_up, HIGH);
  distance = (duration/2) / 29.1;
 

  if (distance <= 50) {
  leds[0] = CRGB(255, 225, 255);
  FastLED.show();
  delay(100);  
  leds[1] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[2] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[3] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[4] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[5] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[6] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[7] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[8] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[9] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[10] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[11] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[12] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[13] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  }
  
{    short duration, distance;
  digitalWrite(trigPin_down, LOW); 
  delayMicroseconds(2);
  digitalWrite(trigPin_down, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin_down, LOW);
  duration = pulseIn(echoPin_down, HIGH);
  distance = (duration/2) / 29.1;
 

  if (distance <= 50) {
  leds[0] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);  
  leds[1] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[2] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[3] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[4] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[5] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[6] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[7] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[8] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[9] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[10] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[11] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[12] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[13] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  }


else
if (trigPin_up, LOW && trigPin_down, HIGH);
  {

  

     short duration, distance;
  digitalWrite(trigPin_down, LOW); 
  delayMicroseconds(2);
  digitalWrite(trigPin_down, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin_down, LOW);
  duration = pulseIn(echoPin_down, HIGH);
  distance = (duration/2) / 29.1;

  if (distance <= 50) {
  leds[13] = CRGB(255, 225, 255);
  FastLED.show();
  delay(100);  
  leds[12] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[11] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[10] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[9] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[8] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  leds[7] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[6] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[5] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[4] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[3] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[2] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[1] = CRGB(255, 255, 255);
  FastLED.show();
   delay(100);
   leds[0] = CRGB(255, 255, 255);
  FastLED.show();
  delay(100);
  }
{
  short duration, distance;
  digitalWrite(trigPin_up, LOW); 
  delayMicroseconds(2);
  digitalWrite(trigPin_up, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin_up, LOW);
  duration = pulseIn(echoPin_up, HIGH);
  distance = (duration/2) / 29.1;

    if (distance <= 50) {
  leds[13] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);  
  leds[12] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[11] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[10] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[9] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[8] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  leds[7] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[6] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[5] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[4] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[3] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[2] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[1] = CRGB(0, 0, 0);
  FastLED.show();
   delay(100);
   leds[0] = CRGB(0, 0, 0);
  FastLED.show();
  delay(100);
  }
}

  }  
} 
 }
 }
7

The code is blocked because you are using delay() function. Use timestamp instead. You can learn how to use a timestamp in BlinkWithoutDelay example

8

I am contemplating a similar project and was planning to use a miniature PIR at the top and the bottom of the stairs, but I like IoT's method better. The railing on my stairs is large enough that the strip can be attached to the underside of the railing and never be touched. My biggest problem will be getting power to the project.

OP- Try to reduce your loop function by separating the clearly definable segments into functions. This helps readability (like finding duplicate code).