ADD GATT-Format for Characteristics

[SFeli]

Hello WiFiuCite,

nice developtment and thx for you pubishing. the code handles all values of sensors in the same format. Some clients are expecting GATT - Format so Temperature GATT-ID 2A6E like uint 16 with exp -2 - so 2343 for 23.43 °C. If you are open for futher features you I can support you with another parameter on characteristics like

Temperature

  - characteristic: "00002a6e-0000-1000-8000-00805f9b34fb"
    exposes: s_BME_T
    GATT_Format: "16_2"

I have implemted in the fork sfeli if you are courios.

Thanks another time for the well done 99% of the solution.

[wifwucite]

Hi, I am happy to hear that you find the component useful. Your proposal sounds like a nice enhancement. Actually I have been thinking about transformations for some time. Your example would be a transformation and another one would be converting a measured battery voltage to an uint8 percentage between 0 and 100. Maybe I should work on that a bit. But I am not sure when I will find the time. ;-)

[webash]

To clarify, if I wanted to use this component to broadcast standard BLE GATT temperature and humidity, what would be the service and characteristic IDs I would use? and will the solution automatically provide the right data format or is that the purpose of this GATT_Format addition?

[SFeli]

Hello the UUID's and Formats for the Environmental Services are link: BLE ServiceUUID 181A : BLEService environmentService BLE CharacterUUID 2A6E : Temperature sint16 (dec -2) BLE CharacterUUID 2A6F : Humidity uint16 (dec -2) BLE CharacterUUID 2A6D : Pressure uint32 (dec -1) and unfortunaltly you have to look and check them on https://www.bluetooth.com/specifications/assigned-numbers/. If you use the App nRF Connect as client the decoding will be done according those formats. As far as I know the setValue() accepts several formats and there is no conversion. There is one issue open on espressif which mention a csv-file for the definition which can be used to generate a bin-file which should be flashed in the ESP. https://github.com/espressif/esp-at/issues/169 - but this is still open.

[webash]

Could you post a full example of your working ESPHome .yaml file that publishes a value like temperature into a environmental sensing service, and a temperature characteristic? please and thank you :)

[SFeli]

substitutions:
  deviceno: "02"
  devicename: esp
  upper_devicename: Bluetooth Low Energy 02

esphome:
  name: $devicename-$deviceno
  friendly_name: ${upper_devicename}
  comment: ESP32-Dev BLE-Controller und Arduino 207
  platformio_options:
    board_build.flash_mode: dio
    upload_speed: 115200

external_components:
  - source: github://sfeli/esphome-ble-controller

esp32:
  board: esp32dev
  framework:
    type: arduino
    version: 2.0.8
    platform_version: 6.1.0

logger:
  level: DEBUG

api:
  encryption:
    key: "your own key"
  reboot_timeout: 0s

ota:
  password: "your own pw"

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password
  fast_connect: True

captive_portal:

i2c:
  sda: 32
  scl: 33
  scan: false 

sensor:
  - platform: bmp280
    id: s_bmp280
    temperature:
      name: "BMP280 Temperature"
      id: "s_BMP_T"
      accuracy_decimals: 1
      oversampling: 16x
    pressure:
      name: "BMP280 Pressure"
      id: "s_BMP_P"
      accuracy_decimals: 1
    address: 0x76
    update_interval: 30s

  - platform: adc
    pin: GPIO36
    id: "i_Batt"
    attenuation: 11db
    update_interval: 30s
    name: "Battery"
    filters:
    - multiply: 10

esp32_ble_controller:
  services:
  - service: "0000181A"
    characteristics:
      - characteristic: "00002a6e-0000-1000-8000-00805f9b34fb"
        exposes: s_BMP_T
        use_BLE2902: true
        GATT_Format: '16_2'
      - characteristic: "00002a6f-0000-1000-8000-00805f9b34fb"
        exposes: s_BM_H
        GATT_Format: '16_2'
      - characteristic: "00002A6D-0000-1000-8000-00805f9b34fb"
        GATT_Format: '32_1'
        exposes: s_BMP_P
  commands:
  security_mode: none
  maintenance: false
  on_connected:
  - logger.log: "Hi I'm connected. :-)"