Meadow BLE Server Sample

BleService.cs

using Meadow.Gateways.Bluetooth;
using Meadow.Logging;
using Meadow.Units;
using System;

namespace Meadow.Samples
{
    public delegate void ClicksChangedHandler(int newValue);

    internal class BleService
    {
        private CharacteristicInt32 _clicksCharacteristic;
        private CharacteristicString _tempCharacteristic;
        private Logger _logger;

        public event ClicksChangedHandler ClicksChanged = delegate { };

        public void SetTemp(Temperature temp)
        {
            _tempCharacteristic.SetValue($"{temp.Fahrenheit:0.0}F");
        }

        public void SetClicks(int clicks)
        {
            _clicksCharacteristic.SetValue(clicks);
        }

        public BleService(Logger logger)
        {
            _logger = logger;

            Initialize();
        }

        private void Initialize()
        {
            var definition = GetDefinition();
            _logger.Info($"Starting BLE Server with {definition.Services[0].Characteristics.Count} characteristics");

            var result = MeadowApp.Device.BluetoothAdapter.StartBluetoothServer(definition);

            if (!result)
            {
                _logger.Error("Failed to start BLE Server");
            }
        }

        private Definition GetDefinition()
        {
            _tempCharacteristic = new CharacteristicString(
                    "temp",
                    uuid: "017e99d6-8a61-11eb-8dcd-0242ac1300aa", // just a random GUID, no particular meaning                    
                    CharacteristicPermission.Read, // temp is read-only
                    CharacteristicProperty.Read,
                    maxLength: 10);

            _clicksCharacteristic = new CharacteristicInt32(
                     "clicks",
                     uuid: "017e99d6-8a61-11eb-8dcd-0242ac1300bb", // just a random GUID, no particular meaning
                     permissions: CharacteristicPermission.Write | CharacteristicPermission.Read, // allow user to reset value
                     properties: CharacteristicProperty.Write | CharacteristicProperty.Read
                     );

            _clicksCharacteristic.ValueSet += OnClicksCharacteristicValueSet;
            var service = new Service(
                 "Meadow",
                 253,
                 _tempCharacteristic,
                 _clicksCharacteristic);

            return new Definition("PROJECT LAB", service);
        }

        private void OnClicksCharacteristicValueSet(ICharacteristic c, object data)
        {
            _logger.Info($"BLE Client set Clicks to {data}");
            ClicksChanged?.Invoke((int)data);
        }
    }
}