Hey guys, I am am trying to make a code which automatically controls relay on basis of ultrasonic sensor measurements. I am using a nodeMCU as a microcontroller rather than an arduino. The relay and the ultrasonic sensor is being powered from a 5V source and nodemcu from a 3.3V Source. I don't think none of the sensors are interfering with each other as all the sensors are kept at a distance.Due to the random values my relay is being latched without any reason. Can someone please help me out with the problem. I don't want these values(above 3000) being shown in the serial monitor. Please help me in the code.
#define TRIGGER 5
#define ECHO 4
#define RELAY 0
void setup() {
Serial.begin(9600);
pinMode(TRIGGER, OUTPUT);
pinMode(ECHO, INPUT);
pinMode(BUILTIN_LED, OUTPUT);
pinMode(RELAY, OUTPUT);
}
void loop() {
long duration, distance;
digitalWrite(TRIGGER, LOW);
delayMicroseconds(10);
digitalWrite(TRIGGER, HIGH);
delayMicroseconds(10);
digitalWrite(TRIGGER, LOW);
duration = pulseIn(ECHO, HIGH);
distance = (duration / 2) / 29.1;
if (distance < 30 ){
digitalWrite(RELAY, HIGH);
}else{
digitalWrite(RELAY, LOW);
}
Serial.print("Centimeters: ");
Serial.println(distance);
}
Put a delay(40) at the end of loop().
Report back.
#define RELAY 0Oops
(uncompiled, untested)
const byte TRIGGER = 5;
const byte ECHO = 4;
const byte RELAY = 6;.
void setup() {
Serial.begin(9600);
pinMode(TRIGGER, OUTPUT);
digitalWrite (TRIGGER, LOW);
pinMode(ECHO, INPUT);
pinMode(BUILTIN_LED, OUTPUT);
pinMode(RELAY, OUTPUT);
}
void loop()
{
digitalWrite(TRIGGER, HIGH);
delayMicroseconds(10);
digitalWrite(TRIGGER, LOW);
unsigned long duration = pulseIn(ECHO, HIGH);
long distance = (duration / 2) / 29.1;
digitalWrite(RELAY, (distance < 30) ? HIGH : LOW);
Serial.print(distance);
Serial.println(F("centimetres"));
delay (40);
}
What kind of sensor is this?
Thirty meter range is a lot more than any I have used.
It is a normal hc-sr04 ultrasonic sensor
IIRC, that has a maximum range of about 4m. Something is wrong, either wiring or math I suspect.
Gates
November 20, 2020, 9:13pm
#8
Hello my friend,
int Nose=0;
int trigger_output[4] = {Nose, 9};// echo 7 trig 8
int echo_input[4] = {7,6};//
int range;
unsigned long distance[2], cm[2], timeout[5];
void setup()
{
Serial.begin (9600);
//------------------------------------
// connect OUTPUT pins to other devices with 470Ω or 1k resistors,
// pinMode (trigger_output[0, 1],OUTPUT);
// Often it is useful to steer an input pin to a known state if no input is present.
// This can be done by adding a pullup resistor (to +5V), or a pulldown resistor
//(resistor to ground) on the input. A 10K resistor is a good value for a pullup or pulldown resistor.
pinMode (echo_input[0],INPUT);
digitalWrite(trigger_output[0], LOW); delayMicroseconds(2);
digitalWrite(trigger_output[0], HIGH); delayMicroseconds(10);
digitalWrite(trigger_output[0], LOW);
//-----------------------------------
pinMode(trigger_output[0], OUTPUT);
pinMode(echo_input[0], INPUT);
// pinMode(trigger_output[1], OUTPUT);
// pinMode(echo_input[1], INPUT);
// range = trig - echo
// iQ4 foxtel
}
void loop() {
digitalWrite(trigger_output[0], LOW);
delayMicroseconds(2);
digitalWrite(trigger_output[0], HIGH);
delayMicroseconds(10);
digitalWrite(trigger_output[0], LOW);
pinMode(echo_input[0], INPUT);
distance[0] = pulseIn(echo_input[0], HIGH);
cm[0] = (distance[0] / 2) / 28;
Serial.print(cm[0]);
Serial.print(" cm");
Serial.println();
delay (10);
// digitalWrite(trigger_output[1], LOW); delayMicroseconds(2);
// digitalWrite(trigger_output[1], HIGH); delayMicroseconds(10);
// digitalWrite(trigger_output[1], LOW);
// pinMode(echo_input[1], INPUT);
// distance[1] = pulseIn(echo_input[0], HIGH);
// cm[1] = (distance[1] / 2) / 28;
// Serial.print(cm[1]);
// Serial.print(" cm");
// Serial.println();
// delay (5);
// digitalWrite(trigger_output[1], LOW);
// delayMicroseconds(2);
// digitalWrite(trigger_output[1], HIGH);
// delayMicroseconds(10);
// digitalWrite(trigger_output[1], LOW);
// pinMode(echo_input[1], INPUT);
// distanceA = pulseIn(echo_input[1], HIGH);
// cmA = (distanceA / 2) / 28;
// Serial.print(cmA);
// Serial.print(" cmA");
// Serial.println();
// delay (5);
}
Hi,
Have you tried the code form this link?
Tom...
