Hello. I have 4 obstacle sensors connected to a nano to run a model railway level crossing sketch. The code, I found online and it is working perfectly.. except.. wall lights in the room are triggering two of the ir sensors when they turn on. I thought it was an ambient light issue, but the problem persists after fitting a "hood" to the sensors.
Open to suggestions. I was considering would it be possible to turn these sensors into breakbeam sensors and would that solve the issue? Or maybe there is a way of altering the code that would be able to handle the ambient light issue.
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#define GATE_SPEED 120 // [ms] lower number is higher servo speed
#define BLINK_SPEED 400 // [ms] smaller number is faster blinking
#define GATE_DELAY 2000 // [ms] time between start blinking and gate closing
#define END_OF_TRAIN_DELAY 2000 // [ms] time to wait before deciding this was the end of the train
#define GATE_OPEN_ANGLE 90
#define GATE_CLOSED_ANGLE 10
#define SERVO_PIN 4
#define LED1_PIN 9
#define LED2_PIN 11
#define NUM_SENSORS 4 // two sensors per track, one left and one right of the gate
byte sensor_pin[NUM_SENSORS] = {5,6,7,8}; // sensor pin numbers
byte state = 1, train_counter, n;
byte led1, led2, blink_enabled;
byte angle = GATE_OPEN_ANGLE;
byte setpoint = GATE_OPEN_ANGLE;
byte sensor_state[NUM_SENSORS]; // 0 idle, 1 detect arrival, 2 detect departure, 3 detect end of train
byte end_of_train[NUM_SENSORS]; // 0 idle, 1 end of train detected
unsigned long time_to_blink;
unsigned long time_to_close_gate;
unsigned long time_for_servo_step;
unsigned long time_end_of_train[NUM_SENSORS];
#include <Servo.h>
Servo gate_servo;
void setup() {
pinMode(LED1_PIN, OUTPUT);
pinMode(LED2_PIN, OUTPUT);
for (byte i = 0; i < NUM_SENSORS; i++) pinMode(sensor_pin[i], INPUT);
gate_servo.attach(SERVO_PIN);
gate_servo.write(angle);
Serial.begin(9600);
Serial.println("Railway Crossing Control Ready");
Serial.println();
Serial.println("Waiting for train");
for (byte i = 0; i < NUM_SENSORS; i++) sensor_state[i] = 1; // enable sensors for train detection
}
void loop() {
for (byte i = 0; i < NUM_SENSORS; i++) {
if(sensor_state[i] == 1) { // detect arrival of new train
if(!digitalRead(sensor_pin[i])) { // train detected
train_counter++;
sensor_state[i] = 0;
if(i%2) n = i - 1; else n = i + 1;
sensor_state[n] = 2; // buddy sensor departure detection enabled
Serial.print("Arrival: ");
Serial.println(i);
Serial.print("Trains: ");
Serial.println(train_counter);
}
}
else if(sensor_state[i] > 1) {
if(!digitalRead(sensor_pin[i])) { // departure detected
time_end_of_train[i] = millis() + (unsigned long)END_OF_TRAIN_DELAY;
if(i%2) n = i - 1; else n = i + 1;
sensor_state[n] = 1; // buddy sensor enabled again
if(sensor_state[i] == 2) {
Serial.print("Departure: ");
Serial.println(i);
}
sensor_state[i] = 3;
}
if(sensor_state[i] == 3) // decide if end of train has passed based on a timer
if(millis() > time_end_of_train[i]) end_of_train[i] = 1;
if(end_of_train[i]) { // this takes care train_counter-- is executed only once
train_counter--;
end_of_train[i] = 0;
sensor_state[i] = 1;
Serial.print("Trains: ");
Serial.println(train_counter);
}
}
}
switch (state) {
case 1: // gate open, not blinking, waiting for train arrival
if(train_counter) state = 12;
break;
case 12: // train arrival detected, blinking
Serial.println("Binking started");
blink_enabled = 1;
time_to_close_gate = millis() + (unsigned long)GATE_DELAY;
state = 2;
break;
case 2: // blinking, wait until it's time to close the gate
if (millis() > time_to_close_gate) state = 23; // gate delay time has passed
break;
case 23: // close the gate
Serial.println("Gate closing");
gate_servo.attach(SERVO_PIN);
setpoint = GATE_CLOSED_ANGLE;
state = 3;
break;
case 3: // gate is closing, blinking
if(angle == setpoint) {
Serial.println("Gate closed");
state = 4;
}
break;
case 4: // gate fullly closed, blinking, waiting for train departure
if(train_counter == 0) state = 45;
break;
case 45: // train departure detected, open the gate, blinking
Serial.println("Gate opening");
gate_servo.attach(SERVO_PIN);
setpoint = GATE_OPEN_ANGLE;
state = 5;
break;
case 5: // wait until gate is fully opened, blinking
if(train_counter) state = 23;
if (angle == setpoint) state = 51;
break;
case 51: // gate is fully opened, stop blinking
// for (byte i = 0; i < NUM_SENSORS; i++) sensor_state[i] = 1;
blink_enabled = 0;
led1 = 0;
led2 = 0;
gate_servo.detach(); // to avoid servo flutter
state = 1;
Serial.println("Gate open, blinking stopped");
Serial.println();
Serial.println("Waiting for train");
break;
}
if (millis() > time_for_servo_step) {
time_for_servo_step = millis() + (unsigned long)GATE_SPEED;
if (angle < setpoint) angle++;
if (angle > setpoint) angle--;
gate_servo.write(angle);
}
if(blink_enabled == 1) {
if(millis() > time_to_blink) {
time_to_blink = millis() + (unsigned long)BLINK_SPEED;
led1 = !led1;
led2 = !led1;
}
}
digitalWrite(LED1_PIN, led1);
digitalWrite(LED2_PIN, led2);
}
`
