I want to call some functions at the rising edge and falling edge of a square wave pulses. I used attachInterrupt(digitalPinToInterrupt(interruptPin), udara, RISING) for rising edge and attachInterrupt(digitalPinToInterrupt(interruptPin), blank,FALLING) for falling edge. But I didn`t get the serial outputs of rise and fall conservatively. what is the answer for the problem? My code is written as follows.
enter code here
const byte interruptPin = 2;
void setup() {
Serial.begin(9600);
pinMode(interruptPin, INPUT);
}
void loop() {
attachInterrupt(digitalPinToInterrupt(interruptPin), udara, RISING);
attachInterrupt(digitalPinToInterrupt(interruptPin), blank, FALLING);
}
void udara() {
Serial.println("rise");
}`
void blank() {
Serial.println("fall");
}
The attachInterrupt() should be part of setup(), not the loop(), as it is used to setup the event trigger and callback.
const byte interruptPin = 2;
void setup() {
Serial.begin(9600);
pinMode(interruptPin, INPUT);
attachInterrupt(digitalPinToInterrupt(interruptPin), udara, RISING);
attachInterrupt(digitalPinToInterrupt(interruptPin), blank, FALLING);
}
void loop() {
}
void udara() {
Serial.println("rise");
}
void blank() {
Serial.println("fall");
}
Serial uses interrupts to push out the data. Those interrupts are disabled during your ISR. For that reason, it is best to avoid using Serial in an ISR. Change the code to set a flag in the ISR and do the printing from loop in response to the flag.
Related
I have a TinkerCad model of a three player quiz game buzzer system and for the first button press detection Im using attachInterrupt().
Detection works. I wanted to light up the onboard LED of arduino with void PinTwoPressed() to see If everything worked and It does. But when I try to print on the LCD I set up in void setup() via PinTwoPressed() It never prints. In void loop() all the print functions work without fail.
Is It because of the library itself or what am I missing?
// C++ code
//
#include <Adafruit_LiquidCrystal.h>
Adafruit_LiquidCrystal lcd(0);
void setup()
{
lcd.begin(16, 2);
lcd.setBacklight(1);
attachInterrupt(digitalPinToInterrupt(2), PinTwoPressed, HIGH);
}
void loop()
{
}
void PinTwoPressed() {
lcd.setCursor(0, 0);
lcd.print("Player");
lcd.setCursor(0, 1);
lcd.print(3);
}
I am trying to have a NodeMCU(ESP32) receive a floating data type from an Arduino Uno but I do not have any idea how. Can someone please guide me through the process? For now, I have the basic serial communication code sending a single digit Int from the Arduino to the NodeMCU.
Sender (Arduino Uno):
int val = 1;
void setup()
{
Serial.begin(19200);
}
void loop()
{
Serial.write(val);
delay(3000);
}
Receiver (NodeMCU):
#include <HardwareSerial.h>
HardwareSerial receiver(2);
void setup()
{
receiver.begin(19200, SERIAL_8N1, 16, 17);
Serial.begin(9600);
}
void loop()
{
if(receiver.available() > 0)
{
int received = receiver.read();
Serial.println(received); //tried printing the result to the serial monitor
}
delay(3000);
}
Write/read in the form you use it, is for single bytes only. A float in Arduino consists of 4 bytes.
You can use write to send a series of bytes, and you have to read those bytes, arriving one after the other, depending on the serial speed. Synchronization/lost bytes might be a problem, here in this simple solution I assume the best.
Sender:
float val = 1.234;
void setup() {
Serial.begin(19200);
}
void loop() {
Serial.write((byte*)&val,4);
delay(3000);
}
Receiver:
#include <HardwareSerial.h>
HardwareSerial receiver(2);
void setup()
{
receiver.begin(19200, SERIAL_8N1, 16, 17);
Serial.begin(9600);
}
void loop()
{
if(receiver.available() > 0)
{
delay(5); // wait for all 4 bytes
byte buf[4];
byte* bp = buf;
while (receiver.available()) {
*bp = receiver.read();
if (bp - buf < 3) bp++;
}
float received = * (float*)buf;
Serial.println(received, 3); // printing the result to the serial monitor
}
delay(100); // not really required, should be smaller than sender cycle
}
I have a simple setup with two Arduinos and a 433MHz transmitter and a receiver module.
The transmitter is set to transmit a string on button press, that side works correctly.
On the receiver end I have a simple program that's just writing whatever it's receiving to serial:
#include "VirtualWire.h"
int rx_pin = 2;
void setup(){
Serial.begin(9600);
Serial.println("serial ready");
vw_set_rx_pin(rx_pin);
vw_setup(2000);
vw_rx_start();
Serial.println("receiver ready");
}
void loop(){
uint8_t msg[VW_MAX_MESSAGE_LEN];
uint8_t msglen = VW_MAX_MESSAGE_LEN;
vw_wait_rx();
if(vw_get_message(msg, &msglen)){
Serial.print("Got: ");
for (int i = 0; i < msglen; i++)
{
Serial.print(char(msg[i]));
}
Serial.println();
}
}
When I then monitor serial, the receiving Arduino seems to receive the message twice each time it's sent. I used an oscilloscope to verify (to the best of my knowledge) that the transmitter is only sending the message once, I also tried wiring the two Arduinos together to make sure the issue is not with the RF modules, I got the same results.
This makes me think there is an issue with my code or with VirtualWire itself.
I'm thinking that I should somehow check if I've received the same message already or I should clear VirtualWire's buffer, how would I do either of those?
EDIT:
Here is the transmitter code:
#include "VirtualWire.h"
int tx_pin =2;
int interruptPin = 3;
volatile bool transmitBool = false;
void setup(){
vw_set_tx_pin(tx_pin);
vw_setup(2000);
pinMode(interruptPin, INPUT_PULLUP);
attachInterrupt(digitalPinToInterrupt(interruptPin), transmit, LOW);
pinMode(13, OUTPUT);
digitalWrite(13, LOW);
transmitBool = false;
}
void loop(){
if(transmitBool) {
transmitBool = false;
digitalWrite(13, HIGH);
vw_send((uint8_t *)"abc", 4);
vw_wait_tx();
delay(500);
digitalWrite(13, LOW);
}
}
void transmit() {
transmitBool = true;
}
It seems that I have a conflict between SoftwareSerial and the delay function on my Arduino (GeekCreit bought on Banggood). I am trying to use SoftwareSerial to send AT commands to an ESP-01.
When I perform:
#include <SoftwareSerial.h>;
SoftwareSerial esp8266(8,9);
void setup() {
Serial.begin(9600);
while (!Serial) ;
esp8266.begin(9600);
esp8266.println("AT");
}
void loop() {
if(esp8266.available()) {
while(esp8266.available()) {
Serial.print(esp8266.read());
}
}
}
Everything works well, the AT command is sent and I receive the response from my ESP.
But when I add a delay before sending the AT command, nothing happens: no command sent, no answer from the ESP.
#include <SoftwareSerial.h>;
SoftwareSerial esp8266(8,9);
void setup() {
Serial.begin(9600);
while (!Serial) ;
esp8266.begin(9600);
delay(2000);
esp8266.println("AT");
}
void loop() {
if(esp8266.available()) {
while(esp8266.available()) {
Serial.print(esp8266.read());
}
}
}
Am I doing something wrong, has someone experienced the same problem?
I have tried to use AltSoftSerial instead but I have the same issue with it.
I have a code that once it receives a particular input over the serial it will turn 2 pins high, and wait for an interrupt to occur and run its code. I tried using an infinite loop(while 1) but the interrupt routine can't get executed when the button is pressed.
I want the outputs LED and BEEP to toggle after 'C' is received and until the interrupt occurs.
// Declarations before
void loop() {
while(Serial.available())
{
char data = Serial.read();
if(data == 'C')
{
digitalWrite(BEEP, 1);
digitalWrite(LED, 1);
flag = true;
}
}
// Interrupt routine
When this code receives a 'C' char from the serial the code starts a led flashing for 50 msec on and for 50 msec off, the led flashing stops when the interrupt ITR_PIN is generated (the ISR buttonPressed function will be called!)
#define ITR_PIN 3
volatile bool start = false;
bool ledstatus = false;
int LED= 4;
/**
* This method is called on the interruption raised on the falling front of the PIN2
* The start flag is used to avoid rebound front. Interruptions are disabled inside the
* interrupt vector method.
* start is reset once it has been processed in the main loop()
*/
void buttonPressed()
{
start=false;
}
void setup()
{
cli();
pinMode(ITR_PIN, INPUT);
pinMode(LED, OUTPUT);
attachInterrupt(0, buttonPressed, FALLING); // Pin 3
sei();
Serial.begin(9600);
}
void loop(){
while(Serial.available())
{
char data = Serial.read();
if(data == 'C')
{
start = true;
}
}
if (start)
{
ledstatus=!ledstatus;
digitalWrite(LED, (ledstatus)?HIGH:LOW);
delay(50);
} else {
if (ledstatus) {
ledstatus=false;
digitalWrite(LED,LOW);
}
}
}
I just tried this on a simulator:
#define ITR_PIN 3
volatile boolean start = false;
volatile boolean flag = false;
int LED= 4;
/**
* This method is called on the interruption raised on the falling front of the PIN2
* The start flag is used to avoid rebound front. Interruptions are disabled inside the
* interrupt vector method.
* start is reset once it has been processed in the main loop()
*/
void buttonPressed()
{
if(flag)
{
if (!start)
{
start = true;
}
}
}
void setup()
{
cli();
pinMode(ITR_PIN, INPUT);
pinMode(LED, OUTPUT);
attachInterrupt(0, buttonPressed, FALLING); // Pin 3
sei();
Serial.begin(9600);
}
void loop(){
while(Serial.available())
{
char data = Serial.read();
if(data == 'C')
{
digitalWrite(LED, 1);
flag = true;
}
}
if(flag == true)
if (start)
{
digitalWrite(LED, LOW);
delay(50);
start = false;
flag=false;
}
}
(it's just a reduced version of yours, I just removed the stepper dependancies and marked flag as volatile). It works with this hardware:
However, I'm pretty sure that you haven't added the pullup to your circuit!
The solution is:
add a resistor (e.g. 10 kOhm) between pin 3 and +5V
enable the internal pullup
Solution 2 is the preferred one: you just have to change
pinMode(ITR_PIN, INPUT);
into
pinMode(ITR_PIN, INPUT_PULLUP);
EDIT:
According to your comment I think that the behavior should be different:
Everything is off
When you receive a C on the serial interface the led starts "blinking"
When the interrupt is asserted it stops blinking.
I modified the code to achieve this; I slightly reduced the rest of the code (but you can merge it with the previous one)
#define ITR_PIN 3
volatile boolean flag = false;
const int blink_period_ms = 500; // Blink period in milliseconds
unsigned long initialBlinkTime;
int LED= 4;
void buttonPressed()
{
flag = false;
}
void setup()
{
cli();
pinMode(ITR_PIN, INPUT);
pinMode(LED, OUTPUT);
attachInterrupt(0, buttonPressed, FALLING); // Pin 3
sei();
Serial.begin(9600);
}
void loop(){
while(Serial.available())
{
char data = Serial.read();
if(data == 'C')
{
if (!flag)
{
initialBlinkTime = millis();
flag = true;
}
}
}
if(flag)
{
int currentTime = millis() - initialBlinkTime;
while (currentTime > blink_period_ms) currentTime -= blink_period_ms;
digitalWrite(LED, currentTime < blink_period_ms/2);
// Insert here the other instructions
delay(50);
}
}