Error in the code

Projects Programming
1

https://create.arduino.cc/projecthub/akansh/advance-automatic-railway-crossing-system-3d43db

I am on the way to designing this project and it shows an error in the section of ultra() and Train(). As I am a beginner of arduino, I don't know where to include this function and how to make it work properly. Anyone plz be kind enough to hep me

2

Are you using the code exactly how it is in that tutorial, or did you make some modifications?

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3

the code from that site has two errors: both ultra() and Train () are undefined. commenting these out makes trainAppear() do nothing.

i don't see any code for the photo sensor that detects the train

4

I submitted a request that the project be removed from the Arduino Project Hub. Since Arduino Project Hub is powered by Hackster.io, the project can still always be available on that site, but I don't feel it is up to the standards I expect from Arduino Project Hub projects.

5

ifkaz

assuming you're still interested in code to support a RR crossing with both road and pedestrian crossings, i wrote code I tested on a multifunction board to do same

the multifunction board has 4 7-segment displays, but there interface is serial. i assume you can use the code from the original link for a directly interface 7-seg display.

you'll also need to borrow the servo code from the original link, add support for a train photo sensor on either side of the crossing using either an LDR or photo transistor and a green LED for the pedestrian crossing.

the code is more dense, fewer sub-functions and essentially a state machine although management of states is spread out

i assume it is a better starting point for your project

// RR/Road/Pedestrian crossing
//     Road LED indicates when train is crossing
//     Pedestrian crossing button triggers 9 second timer
//         and road LED

// drive 7-seg displays on MultiFuction boardj

#include <TimerOne.h>

// -----------------------------------------------
//  constants for multiplexed 7-segment display
#define Latch   4
#define Clock   7
#define Data    8
#define LED0   10
#define LED1   11

byte pins [] = { Latch, Clock, Data, LED0, LED1 };

const byte SEGMENT_MAP_DIGIT[] = {
    0xC0, 0xF9, 0xA4, 0xB0, 0x99, 
    0x92, 0x82, 0xF8, 0X80, 0X90
};

const byte DISP_MAP [] = { 1, 2, 4, 8 };
#define N_DISP  sizeof(DISP_MAP)

byte disp [N_DISP] = {};

// -----------------------------------------------
#define ButPed      A1
#define ButTrain    A2
#define LedPed      13
#define LedRoad  12

enum { ST_CLEAR, ST_TRAIN, ST_PEDESTRIAN };
enum { GO = HIGH, STOP = LOW };

// -----------------------------------------------------------------------------
// shift 16-bits from data into the shift register
void output (
    uint16_t  data)
{
    digitalWrite (Latch, LOW);

    for (unsigned i = 0; i < 16; i++, data <<= 1)  {
        digitalWrite (Data, 0 != (data & 0x8000));

        digitalWrite (Clock, HIGH);
        digitalWrite (Clock, LOW);
    }

    digitalWrite (Latch, HIGH);
}

// -----------------------------------------------------------------------------
// display single 7-segment digit
void
displayDigit (
    byte   val)
{
    output ((SEGMENT_MAP_DIGIT [val] << 8) + DISP_MAP [0]);
}

// -----------------------------------------------------------------------------
// increment the display value every 300 ms
void loop (void)
{
    static byte state       = ST_CLEAR;

    // ----------------------------------------
    // maintain timer
    static byte timer       = 0;

    displayDigit (timer);

    static unsigned long msecLst     = 0;
           unsigned long msec        = millis ();

    if (msec - msecLst > 1000)  {   // decrement timer each second
        msecLst = msec;
        if (timer)  {
            if (0 == --timer)   {   // clear state when timer expires
                state = ST_CLEAR;
                digitalWrite (LedPed,  STOP);
                digitalWrite (LedRoad, GO);
            }
        }
    }

    // ----------------------------------------
    // maintain pedestrian crossing switch
    static byte butPedLst   = HIGH;
           byte butPed      = digitalRead (ButPed);

    if (butPedLst != butPed)  {
        butPedLst = butPed;
        if (LOW == butPed && ST_CLEAR == state)  {
            msecLst = msec;
            timer   = 9;
            state   = ST_PEDESTRIAN;
            digitalWrite (LedPed,  GO);
            digitalWrite (LedRoad, STOP);
        }
    }

    // ----------------------------------------
    // maintain train crossing detection
    if (LOW == digitalRead (ButTrain))  {
        state = ST_TRAIN;
        timer = 0;
        digitalWrite (LedPed,  STOP);
        digitalWrite (LedRoad, STOP);
    }
    else if (ST_TRAIN == state)  {
        state = ST_CLEAR;
        digitalWrite (LedRoad, GO);
    }
}

// -----------------------------------------------------------------------------
void setup (void)
{
    Serial.begin (115200);
    Serial.println ("RR/pedestrian crossing");

    for (unsigned i = 0; i < sizeof(pins); i++)  {
        digitalWrite (pins [i], HIGH);
        pinMode      (pins [i], OUTPUT);
    }

    pinMode (ButPed,  INPUT_PULLUP);
    pinMode (LedPed,  OUTPUT);
    pinMode (LedRoad, OUTPUT);

    digitalWrite (LedPed,  STOP);
    digitalWrite (LedRoad, GO);
}
6

An update on this:

pert:
I submitted a request that the project be removed from the Arduino Project Hub.

The project has been removed from the listings and search results, but it is still accessible via the URL @ifkaz posted above.

So no references to the project have been broken, but also people who are browsing Arduino Project Hub looking for projects won't stumble across this and have a bad time when they find out the code is fatally broken.