I'm using an Arduino Micro to trigger specific events on a front end I have. For some reason, however, some of the key combos are just triggering randomly. I am not even touching the arduino when this happens.
I have it set up so when you press a button, it only triggers the key stroke once, rather than repeating it while the button is pressed.
Am I missing something, or screw something up?
int escButton = 12, valEsc, valEsc2, stateEsc;
int volUp = 11, valVup, valVup2, stateVup;
int volDown = 10, valVdown, valVdown2, stateVdown;
int rebootButton = 9, valReboot, valReboot2, stateReboot;
char ctrlKey = KEY_LEFT_GUI;
char shiftKey = KEY_LEFT_SHIFT;
void pressKeyCombos(int combo){
switch(combo) {
case 1:
Keyboard.press(KEY_ESC);
delay(100);
Keyboard.releaseAll();
break;
case 2:
Keyboard.press(shiftKey);
Keyboard.press(KEY_F1);
delay(100);
Keyboard.releaseAll();
break;
case 3:
Keyboard.press(shiftKey);
Keyboard.press(KEY_F3);
delay(100);
Keyboard.releaseAll();
break;
case 4:
Keyboard.press(shiftKey);
Keyboard.press(KEY_F2);
delay(100);
Keyboard.releaseAll();
break;
}
}
void setup() {
pinMode(escButton, INPUT);
stateEsc = digitalRead(escButton);
Keyboard.begin();
}
void loop(){
valEsc = digitalRead(escButton);
delay(10);
valEsc2 = digitalRead(escButton);
valVup = digitalRead(volUp);
delay(10);
valVup2 = digitalRead(volUp);
valVdown = digitalRead(volDown);
delay(10);
valVdown2 = digitalRead(volDown);
valReboot = digitalRead(rebootButton);
delay(10);
valReboot2 = digitalRead(rebootButton);
if (valVup == valVup2) {
if (valVup != stateVup) {
if (valVup == LOW) {
pressKeyCombos(4);
}
}
stateVup = valVup;
}
if (valVdown == valVdown2) {
if (valVdown != stateVdown) {
if (valVdown == LOW) {
pressKeyCombos(3);
}
}
stateVdown = valVdown;
}
if (valReboot == valReboot2) {
if (valReboot != stateReboot) {
if (valReboot == LOW) {
pressKeyCombos(2);
}
}
stateReboot = valReboot;
}
if (valEsc == valEsc2) {
if (valEsc != stateEsc) {
if (valEsc == LOW) {
pressKeyCombos(1);
}
}
stateEsc = valEsc;
}
}
The inputs are high impedance by default. From your description of the beahvior, I can guess that you have not added external pull up/down resistor and that the pins are connected to a normally open switch. The random input would be just as expected and noted in docs for digitialRead():
Note
If the pin isn't connected to anything, digitalRead() can return
either HIGH or LOW (and this can change randomly).
see reference page for digitialRead()
The micro does have the ability to provide an internal pull up.
Your code does not show you have enabled the internal pull up resistors. This is accomplished in a manner that may seem odd, by writing to the input pin. From the Arduino docs:
There are also convenient 20K pullup resistors built into the Atmega
chip that can be accessed from software. These built-in pullup
resistors are accessed in the following manner.
pinMode(pin, INPUT); // set pin to input
digitalWrite(pin, HIGH); // turn on pullup resistors
see Digital Pins
So in your case, add four digitalWrite()'s in the setup() to enable the pull ups and you look good to go.
Related
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
I'm using an 125Khz RFID module RDM6300 with arduino nano.
While the card is near the RFID reader the loop will read the card multiple times. I want it to read only once while the card is near the reader then read it again if a new connection is being made.
*This code is not writen by me, this is the source:
https://github.com/Wookai/arduino-rfid
// define constants for pins
//int SUCCESS = 10;
//int ERROR = 13;
// variables to keep state
int readVal = 0; // individual character read from serial
unsigned int readData[10]; // data read from serial
int counter = -1; // counter to keep position in the buffer
char tagId[11]; // final tag ID converted to a string
char* authorizedTags[4]; // array to hold the list of authorized tags
// fills the list of authorzied tags
void initAuthorizedTags() {
// add your own tag IDs here
authorizedTags[0] = "0400680B85";
authorizedTags[1] = "0400063EB9";
authorizedTags[2] = "040004F3F5";
authorizedTags[3] = "04006813AB";
}
void setup() {
Serial.begin(9600);
// pinMode(SUCCESS, OUTPUT);
//pinMode(ERROR, OUTPUT);
initAuthorizedTags();
}
// check if the tag ID we just read is any of the authorized tags
int checkTag() {
int i;
for (i = 0; i < 4; ++i) {
if (strcmp(authorizedTags[i], tagId) == 0) {
return 1;
}
}
return 0;
}
// convert the int values read from serial to ASCII chars
void parseTag() {
int i;
for (i = 0; i < 10; ++i) {
tagId[i] = readData[i];
}
tagId[10] = 0;
}
// once a whole tag is read, process it
void processTag() {
// convert id to a string
parseTag();
// print it
printTag();
// check if the tag is authorized
if (checkTag() == 1) {
tagSuccess(); // if so, perform an action (blink a led, open a door, etc...)
} else {
tagFailed(); // otherwise, inform user of failure
}
}
void printTag() {
Serial.print("Tag value: ");
Serial.println(tagId);
}
// perform an action when an authorized tag was read
void tagSuccess() {
Serial.println("Tag authorized.");
// here, we simply turn on the success LED for 2s
// digitalWrite(SUCCESS, HIGH);
//digitalWrite(ERROR, LOW);
// delay(2000);
}
// inform the user that the tag is not authorized
void tagFailed() {
Serial.println("Unauthorized access!");
//digitalWrite(SUCCESS, LOW);
// digitalWrite(ERROR, HIGH);
// delay(2000);
}
// this function clears the rest of data on the serial, to prevent multiple scans
void clearSerial() {
while (Serial.read() >= 0) {
; // do nothing
}
}
void loop() {
// turn LEDs off
// digitalWrite(SUCCESS, LOW);
// digitalWrite(ERROR, LOW);
if (Serial.available() > 0) {
// read the incoming byte:
readVal = Serial.read();
// a "2" signals the beginning of a tag
if (readVal == 2) {
counter = 0; // start reading
}
// a "3" signals the end of a tag
else if (readVal == 3) {
// process the tag we just read
processTag();
// clear serial to prevent multiple reads
clearSerial();
// reset reading state
counter = -1;
}
// if we are in the middle of reading a tag
else if (counter >= 0) {
// save valuee
readData[counter] = readVal;
// increment counter
++counter;
}
}
}
Thank you.
Thank you for your answers. I tried to accept the multiple reads and print only one but it keeps printing "already read" instead of reading the card first time, this is the code:
void printTag() {
if(strcmp(tagId,previous)==1){
strcpy(previous, tagId);
Serial.print("Tag value: ");
Serial.println(tagId);
}
else
{
Serial.print("already read");
}
}
I also tried to put the delay after end of tag but it still reads the card multiple times.
I tried another code, it still reads the tag multiple times.
#include <SoftwareSerial.h>
// RFID | Nano
// Pin 1 | D2
// Pin 2 | D3
SoftwareSerial Rfid = SoftwareSerial(2,3);
int timer=0;
int reference = 1000;
int card_status = 0;
void setup() {
// Serial Monitor to see results on the computer
Serial.begin(9600);
// Communication to the RFID reader
Rfid.begin(9600);
}
void read() {
// check, if any data is available
// as long as there is data available...
while(Rfid.available() > 0 ){
// read a byte
int r = Rfid.read();
// print it to the serial monitor
Serial.print(r, DEC);
Serial.print(" ");
}
// linebreak
Serial.println();
timer=0;
}
void loop()
{
if((Rfid.available() > 0 ) && (card_status == 0) )
{
read();
}
if((!Rfid.available() > 0 ) && (card_status == 1) )
{
card_status=0;
}
}
I'm sorry for the late response. I forgot about this topic.
I solved the problem by making the arduino wait for a response after writing the RFID code for the frist time.
I was able to do that because my arduino was sending the code to a C# application via serial port.
Here is how it works: the arduino prints the RFID code on the serial, from there it is picked up by the C# application which searches a database to see if the code is stored there. Depending on the result, the application prints a character('y' or 'n') which is picked up by the arduino. Depending on the character recieved, the arduino lights up a led ( green or red) and makes a noise. Now a new RFID reading can be made.
Here is the code:
#include <SoftwareSerial.h>
#include "RDM6300.h"
SoftwareSerial rdm_serial(8, 9);
RDM6300<SoftwareSerial> rdm(&rdm_serial);
String comanda;
char c="";
int led_verde = 2;
int led_rosu = 7;
int buzzer = 12;
int i;
void buzz(int n = 1)
{
for (int i = 0; i < n; i++) {
digitalWrite(buzzer, LOW);
delay(200);
digitalWrite(buzzer, HIGH);
delay(200);
}
}
void ledVerde()
{
digitalWrite(led_verde, HIGH);
buzz(1);
delay(1000);
digitalWrite(led_verde, LOW);
}
void ledRosu()
{
digitalWrite(led_rosu, HIGH);
buzz(3);
delay(1000);
digitalWrite(led_rosu, LOW);
}
void setup()
{
pinMode(led_verde, OUTPUT);
pinMode(led_rosu, OUTPUT);
pinMode(buzzer, OUTPUT);
digitalWrite(led_verde, LOW);
digitalWrite(led_rosu, LOW);
digitalWrite(buzzer, HIGH);
Serial.begin(9600);
}
void loop()
{
static unsigned long long last_id = 0;
last_id = rdm.read();
rdm.print_int64(last_id);
Serial.println();
rdm_serial.end();
Serial.flush();
while(!Serial.available());
c=Serial.read();
if(c=='y')
{
ledVerde();
c="";
}
if(c=='n')
{
ledRosu();
}
Serial.flush();
last_id="";
c="";
rdm_serial.begin(9600);
}
You can find the RDM6300 library here: https://github.com/arliones/RDM6300-Arduino
Long time passed the original question, but maybe my answer would be useful for future visitors.
The RDM6300 works by:
automatically reading the data, and then
your code transfers the read data to the buffer for further processing.
Imagine it as a Baggage carousel in the airport. There are multiple luggage (data) on the carousel (reader), and you pick them one by one (transferring to buffer).
So, the problem of multiple reads, is that you have got read data in the reader (luggage on the carousel), that your code is gradually transferring them to the buffer (picking the luggage up).
In our example, if you don't like to collect all luggage, you can ask someone to take some of them, before they reach to you.
The below code does this. While you have data in the reader (the card is near to the reader), it transfers data from reader to buffer and then zeros all of them in the buffer:
First, place this code before "void setup()":
boolean multipleRead = false;
This defines a false/true variable to tell if this is the first time you are reading the tag (false), or it's being read multiple times (true).
Then, put this one at the end of the code block that shows the tag is fully read. If you are using Michael Schoeffler's library for your RDM6300/630 RFID, put it after "else if (ssvalue == 3) {":
multipleRead = true;
It change the variable to true, when your tag is read. That tells the program that your first read is done and the next upcoming read(s) would be "multiple read" and you don't want them.
Then put this at the end of the RFID reader code (if your RFID code is under void loop (), put the below code just after "void loop (){":
if (multipleRead) {
while (ssrfid.available() > 0) {
int ssvalue = ssrfid.read(); // read
if (ssvalue == -1) { // no data was read
break;
}
}
for (int x = 0; x < 14; x++)
{
buffer[x] = 0;
}
multipleRead = false;
}
It empties the reader and then zeros the buffer, while there is a card nearby. When you move the card away, multipleRead value would turn to false, which let another RFID reading loop to initiate.
Hope that helped :)
I guess what you want is a edge trigger instead of level trigger with time limit.
For example, you may prefer to read a RFID card when it firstly comes near to the antenna, once only; when it keeps to contact the antenna, still take no more actions. When you remove the card and place it again near to the antenna, the MCU starts to read the card again.
If so, the following code could be for your reference. What I have done is just to add 1 more flag to keep checking the card_status before checking if a RFID card comes near to the antenna.
int card_status = 0; //0:readable; 1:not-readable
if ( (Serial.available() > 0) && (card_status == 0) ) {
card_status = 1; //disable to read card after exit this loop
//your code, a card is near to the antenna, try to read it.
readVal = Serial.read();
if (readVal == 2) {
counter = 0; // start reading
} else if (readVal == 3) {
processTag();
clearSerial();
counter = -1;
} else if (counter >= 0) {
readData[counter] = readVal;
++counter;
}
}
reset the card status when no RFID signal comes in && card status is true,
if ( (!(Serial.available() > 0)) && (card_status == 1) ) {
card_status = 0; //enable to read card again
//no signal, no card is near to the antenna.
}
You can set a delay (e.g. delay(2000)) after reading the (end of tag). A delay of (say) 2 seconds will allow the user to move the card far enough away from the reader. Note that delay is a blocking command which might not suit your purposes, in which case you could be looking at using the millis count to activate/deactivate the Serial.read.
Another option is to accept the multiple reads, but keep a state of which card has been read. If the new card number is the same as the old card number (within a reasonable timeframe) then just ignore.
I am working on simple project, arduino relay controled via mobile phone. I am trying to create a loop, which makes the relay switch between HIGH and LOW only with sending 1 to pin 7. I tried multiple variations but it never works, I am unable to find a mistake. Here´s the code, thanks in advance.`
int relay = 7;
int prev; //previous value
int val; //actual value
void setup()
{
pinMode(relay, OUTPUT);
Serial.begin(9600);
}
void loop()
{
if(Serial.available()>0) //send data when recieved
{
val = Serial.read(); //read value
}
if (val == '1')
{
if (prev == '1')
{
digitalWrite(relay, LOW);
prev=val;
}
else
{
digitalWrite(relay, HIGH);
prev=val;
}
}
else if (val == '0');
{
if (prev == '0')
{
digitalWrite(relay, HIGH);
prev=val;
}
else
{
digitalWrite(relay, LOW);
prev=val;
}
}
}
Current code attempts to read the serial port, and if has something to read sets it into variable val.
In the case of where it has read a value, but doesnt have another value, val is still set to the same value as before.
So it then probally starts toggling the high/low transition as fast as the loop can go.
Instead, you could move the logic code to within the if(Serial.available()>0) statement so that it only gets called when the key is pressed.
I am trying to wait for user input to start a program operation and then when the user sends a stop command, the loop stops running. I have been unable to get the Serial port to keep reading an input while the loop is running.
So I want the user to Press 1 and then it'll go into the loop and will display the data from the interrupt. But I want it to keep monitoring the Serial Input so when I type in 2, I will get out of the loop and stop printing to the Serial Port.
The serial port isn't registering my second input.
I left out some of the code, but the important stuff should be there.
int userStart = 0; // Holder for user input to start program
int userStop = 0; // Holder for user input to stop program
void setup() {
Serial.begin(115200);
pinMode(motorEncoderA, INPUT);
digitalWrite(motorEncoderA, HIGH); // Pull up resistor
pinMode(motorEncoderB, INPUT);
digitalWrite(motorEncoderB,HIGH); // Pull up resistor
// Interrupt on change of Pin A
attachInterrupt(digitalPinToInterrupt(2), encoderFunc, CHANGE);
Serial.print("Press 1 to start the Process & 2 to Stop");
}
void loop() {
if (Serial.available() > 0)
{
userStart = Serial.read();
if (userStart = 1) {
Serial.print('\n');
while(userStop != 2) {
unsigned long timee = millis();
// Only update if the shaft has moved
if (encoderPositionLast != rotationCounter) {
Serial.print("Time: ");
Serial.print(timee);
Serial.print(" Count: ");
Serial.print (rotationCounter);
Serial.print('\n');
encoderPositionLast = rotationCounter;
Serial.print(userStart);
}
if (Serial.available() > 0) {
userStop = Serial.read();
Serial.print(userStop);
}
}
}
}
Well, I think your problem is that userStart and userStop should not be 1 and 2, but '1' and '2'.
That said, there are some things in your code I dislike.
First of all why is everybody using int as the base type for all numeric variables? If one single byte is enough, use it. On 32bit machines int and byte are almost the same, but on 8bit ones working with ints wastes space and time.
Secondly, I highly discourage you to block the loop function, otherwise you won-t be able to do anything else. Instead, use a variable to track wheter you are running or not, update it with the serial interface, and then execute the code if you are running.
This code should do it. And IMHO it is much better than blocking the loop:
bool running = false;
void setup()
{
...
running = false;
}
void loop()
{
if (Serial.available() > 0)
{
switch(Serial.read())
{
case '1':
running = true;
Serial.print('\n');
break;
case '2':
running = false;
Serial.print("stopped");
break;
}
}
if (running)
{
unsigned long timee = millis();
// Only update if the shaft has moved
if (encoderPositionLast != rotationCounter) {
Serial.print("Time: ");
Serial.print(timee);
Serial.print(" Count: ");
Serial.print (rotationCounter);
Serial.print('\n');
encoderPositionLast = rotationCounter;
Serial.print("running");
}
}
}
As part of a simple Automation project, I was trying to control some LEDs through serial port. I cannot make the following code working
int pin =0;
int state = 0;
void setup() {
Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
}
void loop() {
// send data only when you receive data:
if (Serial.available() > 0) {
// read the incoming byte:
if(Serial.read() == 'S' && Serial.read() == 'S') {
// Command to set the pin
pin = Serial.read() - 65;
state = Serial.read() - '0';
Serial.print("Set State Command received");
// Set the Pin
pinMode(pin, OUTPUT);
digitalWrite(pin, state == 0? LOW:HIGH);
}
}
}
I am sending "SSN1" from my python program to the Arduino serial port for testing, and nothing happens (I have an LED connected on pin 13)
SS - Set State Command
N - (pin no) + 'A' - Pin number 13
1 - State ( 0 = LOW, 1= HIGH)
You want to wait until 4 serial bytes accumulate on the serial buffer.
void loop() {
// polls the serial buffer
while (Serial.available() < 4);
if (Serial.read() == 'S' && Serial.read() == 'S') {
char type = Serial.read();
char pin = Serial.read() - 65;
// do something with the results
}
}
Note that you may want to implement some kind of padding (adding a fixed length of spaces, for example) between inputs, because the serial buffer may drop a byte or overflow, which can lead to unexpected results. Also, some people will complain about the while (Serial.available() < 4) command because computer scientists have been trained to think "polling = bad!", but in the case of an Arduino it makes no difference since it is only running a single task.
By the way, you can also use interrupts with Serial data, but that's out of the scope of this response.
actually I have also battled to get something similar right. due to the problems experienced with serial communication (sometime the messages are slow and sent in pieces, the ACII codes are difficult to remember) I went for a different solution. Basically I added a header ">" and a tail "<"to the message sent to the serial and I featured the Arduino code to consider the message between >< as command. I have then used ATOI to convert string to integer.
In the following code you will see that I have used the following numbers to get Arduino changing the status of pin2 and pin13.
Here are the commands associated to this code:
1000< set pin 13 HIGH,
2000< set pin 13 LOW,
3000< set pin 2 HIGH,
4000< set pin 2 LOW
So, simply send out to the serial those numbers between >< and it should work.
I have used the above also to set PWM speed simply manipulating the strings associated to the received messages. I have not included in this sample the PWM commands but only those related to pin 13 and pin 2. I thought that would be much simpler and safe to use numbers and string identifier to open and close the message.
Load the sketch, open the serial monitor and send >1000<, you should see the internal led on pin 13 lighting up, and so on. let me know if you need any additional help.
char inData[10];
int index;
boolean started = false;
boolean ended = false;
String message = "I am ready!, Send your command....";
void setup(){
Serial.begin(9600);
Serial.println(message);
pinMode (13, OUTPUT);
pinMode (2, OUTPUT);
}
void loop()
{
while(Serial.available() > 0)
{
char aChar = Serial.read();
if(aChar == '>')
{
started = true;
index = 0;
inData[index] = '\0';
}
else if(aChar == '<')
{
ended = true;
}
else if(started)
{
inData[index] = aChar;
index++;
inData[index] = '\0';
}
}
if(started && ended)
{
int inInt = atoi(inData);
// set pin 13 HIGH
if (inInt < 1000)
{
digitalWrite(13, HIGH);
}
//set pin 13 LOW
else if (inInt < 2000)
{
digitalWrite(13, LOW);
}
//set pin 2 HIGH
else if (inInt < 3000)
{
digitalWrite(2, HIGH);
}
//set il pin 2 LOW
else if (inInt < 4000)
{
digitalWrite(2, LOW);
}
started = false;
ended = false;
index = 0;
inData[index] = '\0';
}
}
Look at this example code from Arduino's Physical Pixel Tutorial
const int ledPin = 13; // the pin that the LED is attached to
int incomingByte; // a variable to read incoming serial data into
void setup() {
// initialize serial communication:
Serial.begin(9600);
// initialize the LED pin as an output:
pinMode(ledPin, OUTPUT);
}
void loop() {
// see if there's incoming serial data:
if (Serial.available() > 0) {
// read the oldest byte in the serial buffer:
incomingByte = Serial.read();
// if it's a capital H (ASCII 72), turn on the LED:
if (incomingByte == 'H') {
digitalWrite(ledPin, HIGH);
}
// if it's an L (ASCII 76) turn off the LED:
if (incomingByte == 'L') {
digitalWrite(ledPin, LOW);
}
}
Verify that you see SSN1 coming through on the serial monitor.
I improved my code as it look like this
int pin =0;
int state = 0;
void setup() {
Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
}
void loop() {
// send data only when you receive data:
if (Serial.available() > 3) { // I am using chunk of 4 characters/bytes as a command
// read the incoming byte:
if(Serial.read() == 'S' && Serial.read() == 'S') {
// Command to set the pin
pin = Serial.read() - 65;
state = Serial.read() - '0';
Serial.print("Set State Command received");
// Set the Pin
pinMode(pin, OUTPUT);
digitalWrite(pin, state == 0? LOW:HIGH);
}
delay(50);
}
}
It works perfectly for me. Due to the high frequency of looping, Arduino was not able pickup the bytes for consecutive read. So we are waiting for 4 bytes to accumulate in the buffer to read those (Arduino's serial buffer is 64 bytes).