quadrature encoder using photo interrupts - arduino

I a trying to program an encoder using photo interrupts and a 7474 d flip flop. I believe my wiring is correct. It is simply wiring the photo interrupt to the arduino and having the pin out going through the 7474. Also one of the wires goes to pin 4 to digital read.
Below is my code. For some reason I can't get the photo interrupts to read the turn of the wheel.
const int clock = 0; //pin 2 is interrupt 0
const int dirPin = 4; //the number of the LED pin
//const int ledPin = 13;
int count = 0;
int dir = 0;
//int clockA = 0;
void setup(){
pinMode(dirPin, INPUT);
Serial.begin(9600);
attachInterrupt(clock, program, RISING);
}
void loop()
{
delay(50);
}
void program()
{
dir = digitalRead(dirPin);
if (dir == HIGH)
{
count ++;
}
else
{
count --;
}
Serial.println(count*30);
}

Don't put the Serial.println() in the interrupt handler. Inside a handler other interrupts are disabled. Do as little work as possible and return. The handler should just update the count and can mark a flag to tell the main loop to process.
int count = 0;
int newcounts = 0;
void loop() {
delay(100);
if (newcounts) {
Serial.println(count*30);
newcounts = 0
}
}
void program() {
// ... update count
newcounts = 1;
}

Related

Arduino send bad signal to interrupt pin

I have connected coin hopper and coin acceptor to one arduino uno, coin acceptor connected to pin 2, coin hopper to pin 3 - sensor and pin 7 - relay. When coin hopper switch relay, it is executing coininterrupt
for coin hopper I am using this script link
coin acceptor script: link
I need this 2 scripts working on 1 arduino
my code:
#define SENSOR 3
#define RELAY 7
#define ACCEPTOR 2
volatile boolean insert = false;
int pulse=0,count;
char sen;
int temp=0;
unsigned long int timer;
void setup()
{
Serial.begin(9600);
pinMode(SENSOR,INPUT_PULLUP);
pinMode(RELAY,OUTPUT);
sen=digitalRead(SENSOR);
digitalWrite(RELAY, HIGH);
attachInterrupt(digitalPinToInterrupt(ACCEPTOR), coinInterrupt, RISING);
}
void loop()
{
if (insert) {
insert = false;
Serial.println("coin");
delay(1000);
}
if(Serial.available())
{
timer=millis();
// temp is amount to dispense send to arduino
temp=Serial.parseInt();
if(temp>0){
digitalWrite(RELAY,LOW);}
}
sen=(sen<<1)|digitalRead(SENSOR);
// if hopper sensor read drop coin
if(sen==1)
{
timer=millis();
pulse++;
sen&=0x03;
Serial.println("out 1");
//if dispensed coins equal with coins to dispense stop engine
if(pulse==temp)
{
digitalWrite(RELAY,HIGH);
pulse=0;
temp=0;
}
}
// if amount dispensed is not equal with amount to dispense and engine running, stop
if((digitalRead(RELAY)==LOW)&(millis()-timer>2000))
{
digitalWrite(RELAY,HIGH);
pulse=0;
temp=0;
}
}
void coinInterrupt() {
insert = true;
}
I was trying to change pins (arduino uno support interrupts on pin 2 and 3 only) but problem still appears so I guess there is issue in the code
your sketch does not run in this state :
first fix errors :
declare insert as volatile
remove cpulse (not used anywhere)
change 'if()' to (I suppose) 'if (insert) ....'
remove stuff with 'sen' var : simply use if(digitalRead(SENSOR)) or if(!digitalRead(SENSOR))
except if you need to store relay state.
use logical operators like || or && unless you really need bitwise operations
example of result sketch :
#define SENSOR 3
#define RELAY 7
volatile boolean insert = false;
byte amountToDispense = 0;
int pulse = 0;
int temp = 0;
unsigned long int timer;
void setup()
{
Serial.begin(9600);
pinMode(SENSOR, INPUT_PULLUP);
pinMode(RELAY, OUTPUT);
digitalWrite(RELAY, HIGH);
attachInterrupt(digitalPinToInterrupt(2), coinInterrupt, RISING);
}
void loop()
{
if (insert ) {
insert = false;
Serial.println("coin");
delay(1000);
}
if (Serial.available())
{
timer = millis();
temp = Serial.parseInt();
if (temp > 0) {
//amountToDispense = Serial.read() - 48;
digitalWrite(RELAY, LOW);
}
}
if (digitalRead(SENSOR))
{
timer = millis();
pulse++;
Serial.println("out 1");
if (pulse >= temp)
{
digitalWrite(RELAY, HIGH);
pulse = 0;
temp = 0;
}
}
if (!digitalRead(RELAY) && (millis() - timer > 2000))
{
digitalWrite(RELAY, HIGH);
pulse = 0;
temp = 0;
}
}
void coinInterrupt() {
insert = true;
}
What is this supposed to do?
sen=(sen<<1)|digitalRead(SENSOR);
You init sen with digitalRead(SENSOR);
Assuming that pin is LOW when you start the sketch and turns HIGH, sen will become 1.
Next you do sen &= 0x03 so sen is still 1.
Again sen=(sen<<1)|digitalRead(SENSOR); , sen will either be 2 or 3.
Next loop run sen=(sen<<1)|digitalRead(SENSOR); sen is now 4 or 6. and so on...
I don't have time to think about what you want to achieve but this is definitely a problem as you'll only enter if (sen == 1) once and never again.
If this is not sufficient you should probably improve your post as it is unclear what arduino sends bad signal to interrup pin is supposed to mean. That doesn't make sense. Explain the expected behaviour of your program and how it behaves instead. add more comments so it becomes clear what you intend to do with each block of code so we don't have to interpret

How to control the display and non-display of sensor values ​in Arduino using Bluetooth?

I have a sensor that connects to the body and displays muscle signals.
In the setup guide of this sensor, it is said to upload the following code on Arduino, and when we open the Serial Monitor, the sensor values start to be displayed.
Now I want to control the display of these signals using Bluetooth.
So that when I click on the start button in my App, Serial.print() will start working. Also, when I click on the Stop button, the display of these signals and numbers will stop.
Sensor setup guide is this :
void setup() {
Serial.begin(9600);
}
void loop() {
Serial.println(analogRead(A0));
}
And this is how it works properly :
But when I upload a piece of code that I wrote to my Arduino, it only shows me just on value.
this is my code :
#include <SoftwareSerial.h>
SoftwareSerial BTserial(0, 1); // RX | TX
char Incoming_value = 0;
void setup() {
Serial.begin(9600);
BTserial.begin(9600);
}
void loop() {
Incoming_value = Serial.read(); // "1" is for Start
if (Incoming_value == '1') {
Serial.println(Incoming_value);
StartSensor();
}
}
int StartSensor() {
int sensorValue = analogRead(A0);
Serial.println(sensorValue);
delay(200);
}
also please tell me How to write StopSensor Function for Stop print Sensor Value.
Try this code first (Without Bluetooth module)
#include <SoftwareSerial.h>
SoftwareSerial BTserial(0, 1); // RX | TX
char Incoming_value = 0;
int state = 0;
void setup() {
Serial.begin(9600);
//BTserial.begin(9600);
}
void loop() {
Incoming_value = Serial.read(); // "1" is for Start
if (Incoming_value == '1') {
state = 1;
}
else if (Incoming_value == '0') {
state = 0;
}
if (state == 1) {
StartSensor();
} else {
Serial.println(0);
}
}
int StartSensor() {
int sensorValue = analogRead(A0);
Serial.println(sensorValue);
delay(200);
}

Pausing a loop to run another in Arduino

I'm working on a circuit that has two separate 4-bit binary counters with LEDs. I press a button and one counter begins counting to 15 in binary. I press a second button and the first counter pauses where it is and the second group of LEDs begin counting to 15 in binary. I got both counters working, but I can't get the first group to pause and the second to begin. I've tried using if statements with a boolean flag, but it messes up the first group of LEDs. How can I get ledPins1[] to pause when button2 is pressed, then resume when ledPins2[] finish?
int ledPin1[] = {2,3,4,5};
int ledPin2[] = {7,8,9,10};
int button1 = 11;
int button2 = 12;
boolean button1Last = LOW;
boolean button1Current = LOW;
boolean button2Last = LOW;
boolean button2Current = LOW;
void setup()
{
pinMode(button1, INPUT);
pinMode(button2, INPUT);
for(int i=0; i<4; i++)
{
pinMode(ledPin1[i], OUTPUT);
}
for(int i=0; i<4; i++)
{
pinMode(ledPin2[i], OUTPUT);
}
}
boolean waitForButtonPush1 (boolean lastStartSwitchState1)
{
boolean currentStartSwitchState1 = digitalRead(button1);
if(lastStartSwitchState1 != currentStartSwitchState1) delay(20);
currentStartSwitchState1 = digitalRead(button1);
return currentStartSwitchState1;
}
boolean waitForButtonPush2 (boolean lastStartSwitchState2)
{
boolean currentStartSwitchState2 = digitalRead(button2);
if(lastStartSwitchState2 != currentStartSwitchState2) delay(20);
currentStartSwitchState2 = digitalRead(button2);
return currentStartSwitchState2;
}
void loop()
{
button1Current = waitForButtonPush1(button1Last);
if(button1Last == LOW && button1Current == HIGH)
{
for (byte counter =0;counter<=15; counter++)
{
displayBinary(counter);
delay(500);
}
}
button2Current = waitForButtonPush2(button2Last);
if(button2Last == LOW && button2Current == HIGH)
{
for (byte counter =0;counter<=15; counter++)
{
displayBinary2(counter);
delay(500);
}
}
}
void displayBinary(byte numToShow)
{
for (int i =0;i<4;i++)
{
if (bitRead(numToShow, i)==1)
{
digitalWrite(ledPin1[i], HIGH);
}
else
{
digitalWrite(ledPin1[i], LOW);
}
}
}
void displayBinary2(byte numToShow)
{
for (int i =0;i<4;i++)
{
if (bitRead(numToShow, i)==1)
{
digitalWrite(ledPin2[i], HIGH);
}
else
{
digitalWrite(ledPin2[i], LOW);
}
}
}
Welcome to the world of embedded devices!
Getting a small microprocessor to do several things at the same time is a bit tricky.
The key is to never block. No calls to delay(), no sending large buffers on the serial port at 9600 bauds in one go, etc...
There are some simple techniques to do it, one of the most commonly used is finite state machines.
Let's analyse your app a bit.
2 similar dssplay counters, with delay
2 buttons, buttons usually need to be debounced, that also involves a delay.
Some code, for you to tinker with:
// ****************************
// pinout
static const byte ledPin1[] = { 2, 3, 4, 5 };
static const byte ledPin2[] = { 7, 8, 9, 10 };
constexpr byte button1 = 11; // using constexpr for these saves 2 bytes of RAM.
constexpr byte button2 = 12;
// ****************************
// Counter data
static constexpr unsigned int led_delay = 500; // 500 ms, for all counters.
// constexpr ?? arduino supports c++17. Not all features in the main .ino
// module and all features in .cpp modules.
// Hint: you could have a member variable in the structure below for delay,
// this would allow for counters running at different speeds, or add buttons
// to increase/decrease speed.
// we have only 2 states, but you could add more, like running
// backwards, or run a different chase pattern maybe?
enum class led_counter_state : byte
{
stopped,
running,
};
struct led_counter_data_t
{
led_counter_state state; // STATE
byte counter; // counter current value
unsigned int timestamp; // used for timing.
const byte* leds; // LED pins.
};
static led_counter_data_t led_counter[2];
void led_display_init()
{
for (byte i = 0; i < 2; ++i)
{
led_counter[i].state = led_counter_state::stopped;
led_counter[i].counter = 0;
led_counter[i].timestamp = 0;
}
led_counter[0].leds = ledPin1;
led_counter[1].leds = ledPin2;
}
// ****************************
// LED cotrrol
static void leds_display_value(const led_counter_data_t& cntr)
{
for (byte i = 0, val = cntr.counter; i < 4; ++i, val >>= 1)
digitalWrite(cntr.leds[i], val & 0x01);
}
static void leds_control(led_counter_data_t& cntr)
{
const auto now = (unsigned int)millis(); // keep track of time.
switch(cntr.state)
{
default: // something is wrong.. stop.
cntr.state = led_counter_state::stopped;
// fall through ...
case led_counter_state::stopped:
return; // if not running, do nothing
case led_counter_state::running:
if (now - cntr.timestamp >= led_delay) // check delay
{
if (++cntr.counter > 15) // advance counter.
cntr.counter = 0;
leds_display_value(cntr); // show value.
cntr.timestamp = now; // keep track of time.
}
break;
}
}
static void leds_start(led_counter_data_t& cntr)
{
if (cntr.state != led_counter_state::stopped)
return;
cntr.state = led_counter_state::running;
if (++cntr.counter > 15) // advance counter.
cntr.counter = 0;
led_display_value(cntr); // show value.
cntr.timestamp = (unsigned int)millis();
}
static void leds_stop(led_counter_data_t& cntr)
{
cntr.state = led_counter_state::stopped;
}
// ****************************
// switch inputs data
static constexpr byte switch_debounce_delay = 30; // 30ms is a good value for
// debouncing
struct switch_data_t
{
byte sw1_state : 1; // no need to waste more than 1 bit per switch
byte sw2_state : 1;
byte timestamp; // we'll only count to 30 ms, so 1 byte timestamp will do
};
static switch_data_t switch_data;
// ****************************
// switch inputs code
static void control_inputs()
{
const auto now = (byte)millis();
if (now - switch_data.timestamp < switch_debounce_delay)
return;
switch_data.timestamp = now;
// All switch control logic is regrouped here, and isolated
// form other control code, this makes the logic easier to
// write, read, and debug.
bool b = digitalRead(button1);
if (b & !switch_data.sw1_state) // button was pushed right now.
{
if (led_counter[0].state == led_counter_state::stopped)
{
leds_start(led_counter[0]); // start counter 1
leds_stop(led_counter[1]); // stop counter 2
}
else
{
leds_stop(led_counter[0]); // stop counter 1
}
}
switch_data.sw1_state = b;
b = digitalRead(button2);
if (b & !switch_data.sw2_state) // button was pushed right now.
{
if (led_counter[1].state == led_counter_state::stopped)
{
leds_start(led_counter[1]); // start counter 2
leds_stop(led_counter[0]); // stop counter 1
}
else
{
leds_stop(led_counter[1]); // stop counter 2
}
}
switch_data.sw2_state = b;
}
// ****************************
void setup()
{
pinMode(button1, INPUT);
pinMode(button2, INPUT);
for (byte i = 0; i < 4; ++i)
{
digitalWrite(ledPin1[i], LOW);
pinMode(ledPin1[i], OUTPUT);
digitalWrite(ledPin2[i], LOW);
pinMode(ledPin2[i], OUTPUT);
}
led_display_init();
}
// ****************************
// The goal, always, is to exit loop() as fast as possible, so
// everything will run smoothly, and appear to run simultaneously.
void loop()
{
control_inputs();
leds_control(led_counter[0]);
leds_control(led_counter[1]);
}
I do not have an arduino with me, so I did not comppile nor ran this, but it should be pretty close. Let me know if you're having issues or have any questions.

Ignore interrupt within time range arduino (lowpass filter)

I'm trying to attach interrupts to the rising edge of a signal (PWM). However, the signal is somewhat noisy when it's HIGH which causes the code to register another interrupt when it should not. I obviously tried to fix this in my circuit but that's not quite working so I moved to the software part.
The question is how I can filter out interrupts within a given frequency range? I need to apply a lowpass filter so that the interrupts do not get triggered when the signal is HIGH. My idea was detach the interrupt for a given amount of time or simply ignore the interrupt if it happens within a certain time range.
I'm just not sure how to achieve this.
This is my code:
unsigned long tsend = 0;
unsigned long techo = 0;
const int SEND = 2;
const int ECHO = 3;
unsigned long telapsed = 0;
unsigned long treal = 0;
void setup() {
Serial.begin(115200);
Serial.println("Start");
pinMode(SEND, INPUT);
pinMode(ECHO, INPUT);
attachInterrupt(digitalPinToInterrupt(SEND), time_send, RISING);
attachInterrupt(digitalPinToInterrupt(ECHO), time_echo, RISING);
}
void loop() {
telapsed = techo - tsend;
if (telapsed > 100 && telapsed < 10000000) {
treal = telapsed;
Serial.println(treal);
}
}
void time_send() {
tsend = micros();
}
void time_echo() {
techo = micros();
}
Below is the signal (yellow) which has a lot of noise. I need to ignore the interrupts when the signal is HIGH. Here is an image of the PWM Signal
I would try the following:
#define DEBOUNCE_TIME 100
void time_send() {
static long last = micros() ;
if (last-tsend > DEBOUNCE_TIME)
tsend = last;
}
void time_echo() {
static long last = micros() ;
if (last-techo > DEBOUNCE_TIME)
techo = last;
}
And adjust DEBOUNCE_TIME until I get a satisfactory result.
const byte intrpt_pin = 18;
volatile unsigned int count = 0;
#define DEBOUNCE_TIME 5000
void isr()
{
cli();
delayMicroseconds(DEBOUNCE_TIME);
sei();
count++;
}
void setup()
{
pinMode(intrpt_pin, INPUT_PULLUP);
attachInterrupt(digitalPinToInterrupt(intrpt_pin), isr, FALLING);
}
void loop()
{
}
cli() : Disables all interrupts by clearing the global interrupt mask.
sei() : Enables interrupts by setting the global interrupt mask.
So, basically this program will ignore all the interrupt that occurs between these two lines, that is for DEBOUNCE_TIME.
Check your your interrupt bouncing time and adjust DEBOUNCE_TIME accordingly for the best result.

arduino interrupts with servo motor

currently am working on project to open a door with access code using arduino UNO and a servo motor. Normal operation requires entering access code using keypad which is working fine. Another option requires pressing a button that causes an interrupt to rotate the servo motor. My problem is my interrupt only works once and never works again. Plus how do i put the for-loop to rotate the servo motor inside the interrupt function with a delay. I know that is not possible but am calling another function that has the delayMicroseconds but all this is not working. Below is my implementation please help
#include <Keypad.h>
#include <LiquidCrystal.h>
#include <Servo.h>
Servo servo;
const int openButtonPin = 2;
void setup() {
// put your setup code here, to run once:
servo.attach(5);
pinMode(openButtonPin, INPUT); //Pin 2 is input
attachInterrupt(0, enforceOpenAccess, HIGH); // PIN 2
}
void(* resetFunc)(void) = 0;
void loop()
{
//My other keypad implementations go here
}
void myDelay(int x) // function to cause delay in the interrupt
{
for(int i = 0; i<x; i++)
{
delayMicroseconds(1000);
}
}
void enforceOpenAccess() // ISR
{
for(int k =0; k<=180; k+=2)
{
servo.write(k); //rotate the servo
myDelay(30); //delay the rotation of the servo
}
}
The code above is run on arduino UNO being simulated in proteus and the interrupt button is a push button. Please if there is other ways of implementing that but with the same behaviour as I have described above help out. Thanks a lot
There are a couple of problems in the slice of code you posted. Just for completeness, you should post the loop function, since we can't guess what you wrote inside.
Just one comment: did you put a pullup? Otherwise use INPUT_PULLUP instead of INPUT for the button pinmode.
The main one is that you attached the interrupt for the HIGH mode, which will trigger the interrupt any time the pin is up, not on the rising edge. And please use the macro digitalPinToInterrupt to map to the correct pin:
attachInterrupt(digitalPinToInterrupt(openButtonPin), enforceOpenAccess, RISING);
Then.. Let's improve the code. You really should use the interrupts only when strictly necessary when you have to respond IMMEDIATELY (= less than a couple of milliseconds) to an input. Here you don't have to, so it's MUCH better to check for the button in the loop (more on turning the motor following)
uint8_t lastState;
void setup()
{
...
lastState = LOW;
}
void loop()
{
uint8_t currentState = digitalRead(openButtonPin);
if ((currentState != lastState) && (currentState == HIGH))
{
// Start turning the motor
}
lastState = currentState;
...
}
This will enable you to properly debounce the button too:
#include <Bounce2.h>
Bounce debouncer = Bounce();
void setup()
{
...
pinMode(openButtonPin, INPUT); //Pin 2 is input
debouncer.attach(openButtonPin);
debouncer.interval(5); // interval in ms
}
void loop()
{
debouncer.update();
if (debouncer.rose())
{
// Start turning the motor
}
...
}
If, on the other way, you REALLY want to use the interrupts (because waiting for a couple of milliseconds is too much for you), you should do something like this:
#include <Bounce2.h>
Bounce debouncer = Bounce();
void setup()
{
...
pinMode(openButtonPin, INPUT);
attachInterrupt(digitalPinToInterrupt(openButtonPin), enforceOpenAccess, RISING);
}
void loop()
{
...
}
void enforceOpenAccess() // ISR
{
// Start turning the motor
}
It looks like your code? No, because now we'll speak about turning the motor
You should NOT use delays to make steps, because otherwise you will wait for 30ms * 180 steps = 5.4s before being able to do anything else.
You can, however, make a sort of reduced state machine. You want your servo to move from 0 to 180 in steps of 1. So let's code the "don't move" state with any value greater than 180, and consequently we can do something like this in the loop:
unsigned long lastServoTime;
uint8_t servoPosition = 255;
const int timeBetweenSteps_in_ms = 30;
void loop()
{
...
if (servoPosition <= 180)
{ // servo should move
if ((millis() - lastServoTime) >= timeBetweenSteps_in_ms)
{
lastServoTime += timeBetweenSteps_in_ms;
servoPosition++;
if (servoPosition <= 180)
servo.write(servoPosition);
}
}
}
Then, using any of the previous examples, instead of // Start turning the motor write
lastServoTime = millis();
servoPosition = 0;
servo.write(servoPosition);
This way you won't block the main loop even when the button is pressed
This is what is in my loop()
char key = keypad.getKey();
if(key)
{
if(j < 10)
{
studentNumber[j] = key;
//holdMaskedNumber[j] = '*';
lcd.setCursor(0,2);
lcd.print(String(studentNumber));
if(j == 9)
{
studentNumber[9] = '\0';
//holdMaskedNumber[9] = 0;
lcd.clear();
//String number = String(studentNumber);
//lcd.print(number);
//delay(1000);
//lcd.clear();
lcd.print("Access Code");
}
j++;
}
else
{
if(i < 5)
{
accessCode[i] = key;
holdMaskedCode[i] = '*';
lcd.setCursor(1,2);
lcd.print(String(holdMaskedCode));
if(i == 4)
{
holdMaskedCode[5] = '\0';
accessCode[5] = '\0';
//lcd.clear();
//lcd.setCursor(0,0);
//accessCodeString = String(accessCode);
//lcd.print(accessCodeString);
//delay(1000);
lcd.clear();
for(int i =0; i<6; i++)
{
lcd.print("Please wait.");
delay(500);
lcd.clear();
lcd.print("Please wait..");
delay(500);
lcd.clear();
lcd.print("Please wait...");
delay(500);
lcd.clear();
}
digitalWrite(4, HIGH);
lcd.print("Access Granted");
for(int k =0; k<=180; k+=2)
{
servo.write(k);
delay(30);
}
resetFunc();
}
i++;
}
}
}

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