alexis CruzSamreen IslamCarlos ChacinAlie Gonzalez
Published © GPL3+

Get Started with Bluetooth on MATRIX Voice ESP32

Send simple Bluetooth queries to control your MATRIX Voice's LEDs.

IntermediateFull instructions provided30 minutes3,075

Things used in this project

Hardware components

MATRIX Voice
MATRIX Labs MATRIX Voice
×1
Raspberry Pi 3 Model B
Raspberry Pi 3 Model B
×1

Software apps and online services

Arduino IDE
Arduino IDE

Story

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Code

Bluetooth Arduino Code File

C/C++
The Arduino code setting up Bluetooth for the ESP32 MATRIX Voice.
#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEServer.h>
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include "wishbone_bus.h"
#include "everloop.h"
#include "everloop_image.h"

namespace hal = matrix_hal;

// MATRIX LED Vars
static hal::WishboneBus wb;
static hal::Everloop everloop;
static hal::EverloopImage image;

//Define custom bluetooth service ID
//Randomly Generate UUID (Universal Unique ID) at https://www.uuidgenerator.net/
#define LED_CONTROL_SERVICE_UUID "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
#define COLOR_VALUE_UUID "beb5483e-36e1-4688-b7f5-ea07361b26a8"

//Declare empty bluetooth variable
BLEServer *My_ESP32 = NULL;
BLEService *Led_Control = NULL;
BLECharacteristic *Led_Color = NULL;

void setup()
{
  //begin console printing
  Serial.begin(115200);
  
  //Setup the esp32 as the Bluetooth Server
  Serial.println("Starting BLE work!");
  BLEDevice::init("My_ESP32_Voice");
  My_ESP32 = BLEDevice::createServer();
  
  //create a service for controling the LEDs
  Led_Control = My_ESP32->createService(LED_CONTROL_SERVICE_UUID);
  
  //create a readable/writeable characteristic (i.e. bluetooth variable)
  Led_Color = Led_Control->createCharacteristic(COLOR_VALUE_UUID, BLECharacteristic::PROPERTY_READ | BLECharacteristic::PROPERTY_WRITE);
  
  // Setup the Everloop
  wb.Init();
  everloop.Setup(&wb);
  
  //set the initial value to blue and start the service
  Led_Color->setValue("blue");
  Led_Control->start();
  
  //start advertising the Voice's Service to other bluetooth devices
  BLEAdvertising *advertising = BLEDevice::getAdvertising();
  advertising->addServiceUUID(LED_CONTROL_SERVICE_UUID);
  advertising->setScanResponse(true);
  advertising->setMinPreferred(0x06); // functions that help with iPhone connections issue
  advertising->setMinPreferred(0x12);
  BLEDevice::startAdvertising();
  
  Serial.println("Color defined! Now you can read/change it in your phone!");
}
void loop()
{
  try
  {
      //convert the string sent to a number if possible
      int value = 0, r = 0, b = 0, g = 0;
      sscanf(Led_Color->getValue().c_str(), "%d", &value);
      if(Led_Color->getValue() == "blue"){
        b = 255;
      }
      else if(Led_Color->getValue() == "red"){
        r = 255;
      }
      else if(Led_Color->getValue() == "green"){
        g = 255;
      }
      else if(value <= 255 && value >= 0){
        r = b = g = value;
      }
      for (hal::LedValue &led : image.leds)
      {
          led.red = r;
          led.green = g;
          led.blue = b;
          led.white = 0;
      }
      everloop.Write(&image);
  }
  
  //catch all exceptions
  catch (...)
  {
    Serial.println("Errors happening");
  }
  delay(2000);
}

ESP32 Arduino Bluetooth

Bluetooth example with MATRIX Voice ESP32

Credits

alexis Cruz

alexis Cruz

8 projects • 12 followers
Samreen Islam

Samreen Islam

21 projects • 76 followers
Carlos Chacin

Carlos Chacin

23 projects • 49 followers
Software Developer
Alie Gonzalez

Alie Gonzalez

21 projects • 64 followers
✨ Creative Technologist 💡 Arm Innovator 💼 Formerly: SparkFun, MATRIX Labs, & AdMobilize

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Related channels and tags
  • MATRIX Labs
  • Raspberry Pi
  • Voice