I am trying to get my Adafruit Trinket working as a keyboard. I am using the standard example code for it but it keeps giving me this compilation error.
exit status 1
'Keyboard' not found. Does your sketch include the line '#include <Keyboard.h>'?
this error keeps popping up even though i have it in my code. I have tried lots of different versions of this and messed with lots of things and it has always came up with this error.
This is my code.
#include <Keyboard.h>
const int buttonPin = 4; // input pin for pushbutton
int previousButtonState = HIGH; // for checking the state of a pushButton
int counter = 0; // button push counter
void setup() {
// make the pushButton pin an input:
pinMode(buttonPin, INPUT);
// initialize control over the keyboard:
Keyboard.begin();
}
void loop() {
// read the pushbutton:
int buttonState = digitalRead(buttonPin);
// if the button state has changed,
if ((buttonState != previousButtonState)
// and it's currently pressed:
&& (buttonState == HIGH)) {
// increment the button counter
counter++;
// type out a message
Keyboard.print("You pressed the button ");
Keyboard.print(counter);
Keyboard.println(" times.");
}
// save the current button state for comparison next time:
previousButtonState = buttonState;
}
The Keyboard.h library is for the official Arduino boards with native USB support.
For the Trinket you need to use the TrinketKeyboard.h from Adafruit.
Related
I am using a Feather Express NRF52840 and am trying to make use of the presupplied user button.
Reading the pinout says:
A tactile switch is provided for use in your projects, which is connected to P1.02 and is accessible in code as D7 in Arduino and SWITCH in CircuitPython.
I am using example code to read the button's state change.
The problem I am having is that the code will not compile when I use D7 rather than A1 in the original code. The error I get is:
sketch_nov04a:1:23: error: 'D7' was not declared in this scope; did you mean 'A7'?
1 | const int buttonPin = D7; // the number of the pushbutton pin
| ^~
| A7
exit status 1
'D7' was not declared in this scope; did you mean 'A7'?
I considered using A7 thinking the error message might be right but reading the pinout, AREF (A7/P0.31) is already in use.
What am I missing?
const int buttonPin = D7; // the number of the pushbutton pin
int buttonState; // the current reading from the input pin
int lastButtonState = HIGH; // the previous reading from the input pin
void setup() {
Serial.begin(115200);
delay(100);
pinMode(buttonPin, INPUT_PULLUP);
}
void loop() {
int reading = digitalRead(buttonPin);
if (reading != lastButtonState) {
Serial.println("I ATE THE PIE!!");
}
}
Try:
const int buttonPin = 7;
There are probably macros defining A0 etc., but as far as I know there aren't any for D0 etc.; for those you just use the number, without the "D".
I'm having some issues getting my code to do what I want on my Arduino Mega. What I'm aiming to do is to have the same RFID tag change an LED colour from red to green and when presented again from green to red. I also want to do this with a button. This is for a door lock so that the door can been locked and unlocked from both sides of the door.
The code below will allow an RFID tag to change the colour from red to green and vice versa but as soon as I try to test for an authenticated card it fails miserably. Also when I try to add the button to it my code ends up getting very messy and unusable. I've tried various things but I think my major problem is because the code sites inside the loop function. I've tried while(1) when trying to set the LED to a particular colour but it just doesn't work properly.
This I thought would be fairly trivial to do, maybe it is, I'm just not familiar enough with this.
Can anyone help point me in the right direction which will help me move further forward with this?
#include <SPI.h>
#include <MFRC522.h>
// constants won't change. They're used here to set pin numbers:
const int BUTTON_PIN = 2; // the number of the pushbutton pin
#define BLUE 7
#define GREEN 6
#define RED 3
#define RST_PIN 9 // Configurable, see typical pin layout above
#define SS_PIN 53 // Configurable, see typical pin layout above
// Variables will change:
String authKeyFob = "54321098765";
String card_ID="";
//int lastState = HIGH; // the previous state from the input pin
//int currentState = LOW; // the current reading from the input pin
int buttonState = 0; // current state of the button
int lastButtonState = 0; // previous state of the button
int ledState = 0; // remember current led state
int rfidState = 0;
int lastRfidState = 0;
bool toggle = false;
bool cardValid = false;
MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance
void setup() {
// initialize serial communication at 9600 bits per second:
Serial.begin(9600);
while (!Serial); // Do nothing if no serial port is opened (added for Arduinos based on ATMEGA32U4)
SPI.begin(); // Init SPI bus
mfrc522.PCD_Init(); // Init MFRC522 card
// initialize the pushbutton pin as an pull-up input
// the pull-up input pin will be HIGH when the switch is open and LOW when the switch is closed.
pinMode(BUTTON_PIN, INPUT);
pinMode(GREEN, OUTPUT);
pinMode(RED, OUTPUT);
pinMode(BLUE, OUTPUT);
}
void loop() {
// read the state of the switch/button:
buttonState = digitalRead(BUTTON_PIN);
// Look for new cards, and select one if present
if (mfrc522.PICC_IsNewCardPresent() || mfrc522.PICC_ReadCardSerial() ) {
if(toggle == false){
toggle = true;
} else {
toggle = false;
}
delay(200);
}
if(toggle == 1){
digitalWrite(GREEN, HIGH);
digitalWrite(RED, LOW);
} else if (toggle == 0) {
digitalWrite(GREEN, LOW);
digitalWrite(RED, HIGH);
}
}
All you need to do is to have another if statement that reads your button and toggles your toggle variable just like you do for the card. See if you understand what's going on here:
void loop() {
// read the state of the switch/button:
oldButtonState = LOW; // NEED TO ADD A DECLARATION FOR THIS BEFORE SETUP
buttonState = digitalRead(BUTTON_PIN);
// Look for new cards, and select one if present
if (mfrc522.PICC_IsNewCardPresent() || mfrc522.PICC_ReadCardSerial() ) {
toggle = !toggle; // A way easier way to write the if statements you had.
}
// if the button just became pressed...
if(buttonState == HIGH && oldButtonState==LOW){
toggle = !toggle; // same thing, toggle our variable.
}
oldButtonState = buttonState; // save the button state for next time
if (toggle) {
digitalWrite(GREEN, HIGH);
digitalWrite(RED, LOW);
} else {
digitalWrite(GREEN, LOW);
digitalWrite(RED, HIGH);
}
}
See the State Change Example to see why I store the old state of the button. I also changed that set of if statements to just set toggle to not toggle, that's an easier way to reverse a boolean value. I also made that last else if just an else since a boolean can only have two values. If it isn't true then it must be false.
This is my updated version with the RFID tag working consistently with the button and LED.
void loop() {
// read the state of the switch/button:
oldButtonState = LOW; // NEED TO ADD A DECLARATION FOR THIS BEFORE SETUP
buttonState = digitalRead(BUTTON_PIN);
// Look for new cards, and select one if present
if (!mfrc522.PICC_IsNewCardPresent() ) {
}
if(mfrc522.PICC_ReadCardSerial() ){
toggle = !toggle;
delay(200);
}
// if the button just became pressed...
if(buttonState == HIGH && oldButtonState==LOW){
toggle = !toggle; // same thing, toggle our variable.
delay(200);
}
oldButtonState = buttonState; // save the button state for next time
if (toggle) {
digitalWrite(GREEN, HIGH);
digitalWrite(RED, LOW);
} else {
digitalWrite(GREEN, LOW);
digitalWrite(RED, HIGH);
}
}
Functionality:
When user presses the big dome push button, the state of Arduino should turn from '0'/LOW to '1'/HIGH at the serial monitor of the Arduino.
Issue:
When I trigger on the big dome push button, the state did not trigger from LOW to HIGH, it still remained LOW.
I have connected the "Push To Make" side of the connection to digital pin 2, following the connection write-up from: BIG DOME PUSH BUTTON.
However at this point, the trigger state is not working, please assist.
const int buttonPin = 2; //the number for the pushbutton pin (DIGITALPIN)
uint8_t btnCnt = 1;
bool outputState = false;
void setup() {
Serial.begin(9600);
//for Push button pin
pinMode(buttonPin, INPUT);
}
void loop() {
outputState |= digitalRead(buttonPin); // if pushButton is high, set outputState (low does nothing)
// Print the output
if (outputState) {
switch (btnCnt++) {
case 100:
--btnCnt;
outputState = false;
break;
}
Serial.println("1");
} else {
Serial.println("0");
btnCnt = 0;
}
delay(100);
}
The statement outputState |= digitalRead(buttonPin); is using an OR assign so once outputState is set to 1 (HIGH), it will never go back to 0 (LOW) again. This is because performing an OR with anything and a 1 will always result in 1.
If you change this line to just an assignment as follows, you should see the state change you are expecting. outputState = digitalRead(buttonPin);
I have put together an Arduino circuit that turns the led's off when the button is pressed. How do I code it so when I press it once it comes on and stays on and will only turn off once its pressed again? Any help would be appreciated
My Current code is:
int ledred = 12;
int ledgreen = 8;
int BUTTON = 4;
int speakerPin = 1;
void setup() {
// initialize the digital pin as an output.
Serial.begin(9600);
pinMode(ledgreen, OUTPUT);
pinMode(ledred, OUTPUT);
pinMode(BUTTON,INPUT);
}
void loop() {
if(digitalRead(BUTTON) == HIGH){
digitalWrite(ledred,HIGH);
digitalWrite(ledgreen,HIGH);
}else
{
digitalWrite(ledred,LOW);
digitalWrite(ledgreen,LOW);
}
}
If all you want is do this, you can use one of the interrupt pins and watch for the RISING (or FALLING) event.
Something similar to this example:
const byte ledPin = 13;
const byte interruptPin = 2;
volatile byte state = LOW;
void setup() {
pinMode(ledPin, OUTPUT);
pinMode(interruptPin, INPUT_PULLUP);
attachInterrupt(digitalPinToInterrupt(interruptPin), blink, RISING);
}
void loop() {
digitalWrite(ledPin, state);
}
void blink() {
state = !state;
}
Mind that you may still need some debouncing strategy.
Also, you don't need to use an interrupt for that, but then you'd need some edge-detection algorithm. These are quite well explained in the debouncing article above. I personally prefer these, since interrupt pins in the UNO board are precious enough not to be used with humble button pressings... :o)
/*
Debounce
Each time the input pin goes from LOW to HIGH (e.g. because of a push-button
press), the output pin is toggled from LOW to HIGH or HIGH to LOW. There's a
minimum delay between toggles to debounce the circuit (i.e. to ignore noise).
The circuit:
- LED attached from pin 13 to ground
- pushbutton attached from pin 2 to +5V
- 10 kilohm resistor attached from pin 2 to ground
- Note: On most Arduino boards, there is already an LED on the board connected
to pin 13, so you don't need any extra components for this example.
created 21 Nov 2006
by David A. Mellis
modified 30 Aug 2011
by Limor Fried
modified 28 Dec 2012
by Mike Walters
modified 30 Aug 2016
by Arturo Guadalupi
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/Debounce
*/
// constants won't change. They're used here to set pin numbers:
const int buttonPin = 2; // the number of the pushbutton pin
const int ledPin = 13; // the number of the LED pin
// Variables will change:
int ledState = HIGH; // the current state of the output pin
int buttonState; // the current reading from the input pin
int lastButtonState = LOW; // the previous reading from the input pin
// the following variables are unsigned longs because the time, measured in
// milliseconds, will quickly become a bigger number than can be stored in an int.
unsigned long lastDebounceTime = 0; // the last time the output pin was toggled
unsigned long debounceDelay = 50; // the debounce time; increase if the output flickers
void setup() {
pinMode(buttonPin, INPUT);
pinMode(ledPin, OUTPUT);
// set initial LED state
digitalWrite(ledPin, ledState);
}
void loop() {
// read the state of the switch into a local variable:
int reading = digitalRead(buttonPin);
// check to see if you just pressed the button
// (i.e. the input went from LOW to HIGH), and you've waited long enough
// since the last press to ignore any noise:
// If the switch changed, due to noise or pressing:
if (reading != lastButtonState) {
// reset the debouncing timer
lastDebounceTime = millis();
}
if ((millis() - lastDebounceTime) > debounceDelay) {
// whatever the reading is at, it's been there for longer than the debounce
// delay, so take it as the actual current state:
// if the button state has changed:
if (reading != buttonState) {
buttonState = reading;
// only toggle the LED if the new button state is HIGH
if (buttonState == HIGH) {
ledState = !ledState;
}
}
}
// set the LED:
digitalWrite(ledPin, ledState);
// save the reading. Next time through the loop, it'll be the lastButtonState:
lastButtonState = reading;
}
I currently have an arduino LCD and one SPDT switch connected to my board. The the common pin of the SPDT is grounded and the outer pins are each connected to a digital input. My program should increment and decrement the counter being printed to the LCD screen. I have one input working that increments the counter I do not know how to implement code for the input to decrement the counter. Code posted below.
Thank you
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5,4,3,2);
const byte buttonPin = 8;
int counter = 0; // set your counter to zero to begin with
byte buttonState; // the current reading from the input pin
byte lastButtonState = HIGH; // the previous reading from the input pin
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;
void setup()
{
Serial.begin(9600);
pinMode(buttonPin, INPUT_PULLUP);
lcd.begin(16, 2); // for 2x16 lcd display
}
void loop() {
// read the state of the switch into a local variable:
byte reading = digitalRead(buttonPin);
// check to see if you just pressed the button
// (i.e. the input went from HIGH to LOW), and you've waited
// long enough since the last press to ignore any noise:
// If the switch changed, due to noise or pressing:
if (reading != lastButtonState) {
// reset the debouncing timer
lastDebounceTime = millis();
}
if ((millis() - lastDebounceTime) >= debounceDelay) {
// whatever the reading is at, it's been there for longer
// than the debounce delay, so take it as the actual current state:
// if the button state has changed:
if (reading != buttonState) {
buttonState = reading;
if (buttonState == LOW) {
counter ++;
Serial.println(counter);
lcd.setCursor(0, 1);
lcd.print(counter);
}
}
}
lastButtonState = reading;
}
You cannot simply connect one pole of a switch to an input pin an other to the ground. This will detect LOW but when when you are suppose to detect HIGH on the pin, it will be floating. Connect a pull-up resistor to your input pins.
Or you can use pinMode(InPin, INPUT_PULLUP);
This will pull your input pin to high internally and then you can detect the swithces and implememnt the code.