Hi, I am trying to create a peripheral that sends updates for 2 separate buttons. I attempted duplicate the buttonCharacteristic as shown below but I am having a couple of issues.
-
button3 works backwards. once I press it and let go the LED stays on. It only turns off when I hold down button 3 or press button2.
-
when I press either button then both Characteristics are updated the Light Blue app. So for example if I press button2 I get a updated value for characteristic2 and characteristic3 in the app and vice versa.
Is the ledService a bad service to use for this application? Is there a better one to use without creating a custom service?
Should I be creating multiple instances of the ledService instead of creating multiple characteristics for the buttons?
Thanks so much!
/*
Button LED
This example creates a BLE peripheral with service that contains a
characteristic to control an LED and another characteristic that
represents the state of the button.
The circuit:
- Arduino MKR WiFi 1010, Arduino Uno WiFi Rev2 board, Arduino Nano 33 IoT,
Arduino Nano 33 BLE, or Arduino Nano 33 BLE Sense board.
- Button connected to pin 4
You can use a generic BLE central app, like LightBlue (iOS and Android) or
nRF Connect (Android), to interact with the services and characteristics
created in this sketch.
This example code is in the public domain.
*/
#include <ArduinoBLE.h>
const int ledPin = LED_BUILTIN; // set ledPin to on-board LED
const int button2Pin = 2; // set buttonPin to digital pin 4
const int button3Pin = 3; // set buttonPin to digital pin 5
BLEService ledService("19B10010-E8F2-537E-4F6C-D104768A1214"); // create service
// create switch characteristic and allow remote device to read and write
BLEByteCharacteristic ledCharacteristic("19B10011-E8F2-537E-4F6C-D104768A1214", BLERead | BLEWrite);
// create button characteristic and allow remote device to get notifications
BLEByteCharacteristic button2Characteristic("19B10012-E8F2-537E-4F6C-D104768A1214", BLERead | BLENotify);
BLEByteCharacteristic button3Characteristic("19B10013-E8F2-537E-4F6C-D104768A1214", BLERead | BLENotify);
void setup() {
Serial.begin(9600);
while (!Serial);
pinMode(ledPin, OUTPUT); // use the LED as an output
pinMode(button2Pin, INPUT); // use button pin as an input
pinMode(button3Pin, INPUT); // use button pin as an input
// begin initialization
if (!BLE.begin()) {
Serial.println("starting BLE failed!");
while (1);
}
// set the local name peripheral advertises
BLE.setLocalName("2ButtonLED");
// set the UUID for the service this peripheral advertises:
BLE.setAdvertisedService(ledService);
// add the characteristics to the service
ledService.addCharacteristic(ledCharacteristic);
ledService.addCharacteristic(button2Characteristic);
ledService.addCharacteristic(button3Characteristic);
// add the service
BLE.addService(ledService);
ledCharacteristic.writeValue(0);
button2Characteristic.writeValue(0);
button3Characteristic.writeValue(0);
// start advertising
BLE.advertise();
Serial.println("Bluetooth device active, waiting for connections...");
}
void loop() {
// poll for BLE events
BLE.poll();
// read the current button pin state
char button2Value = digitalRead(button2Pin);
// has the value changed since the last read
boolean button2Changed = (button2Characteristic.value() != button2Value);
if (button2Changed) {
// button state changed, update characteristics
ledCharacteristic.writeValue(button2Value);
button2Characteristic.writeValue(button2Value);
}
if (ledCharacteristic.written() || button2Changed) {
// update LED, either central has written to characteristic or button state has changed
if (ledCharacteristic.value()) {
Serial.println("LED on");
digitalWrite(ledPin, HIGH);
} else {
Serial.println("LED off");
digitalWrite(ledPin, LOW);
}
}
char button3Value = digitalRead(button3Pin);
boolean button3Changed = (button3Characteristic.value() != button3Value);
if (button3Changed) {
// button state changed, update characteristics
ledCharacteristic.writeValue(button3Value);
button3Characteristic.writeValue(button3Value);
}
if (ledCharacteristic.written() || button3Changed) {
// update LED, either central has written to characteristic or button state has changed
if (ledCharacteristic.value()) {
Serial.println("LED on");
digitalWrite(ledPin, HIGH);
} else {
Serial.println("LED off");
digitalWrite(ledPin, LOW);
}
}
}
