CC2640 Home Automation

This project is an application for building Bluetooth low energy (BLE) sensors and actuators based on the TI CC2640 and CC2650 SoC.

Currently, the supported modules include:

• Sensors:
  • Button / switch
  • Reed switch
  • OPT3001 ambient light sensor
  • BME280 enviromental sensor (pressure, temperature and humidity)
  • Thermistor temperature sensor
  • PIR motion sensor
• Actuators:
  • Relay and latching relay
  • LED
  • WS2812B addressable RGB LEDs

Services and Characteristics

Depending on the modules enabled in the board file, the following GATT services and characteristics may be exposed:

• 0000180f-0000-1000-8000-00805f9b34fb Battery Service
  • 00002a19-0000-1000-8000-00805f9b34fb Battery Level (read, notify)
    • A uint8 in percent describing the battery level
• 0000181a-0000-1000-8000-00805f9b34fb Environmental Sensing
  • 00002a6d-0000-1000-8000-00805f9b34fb Pressure (read, notify)
    • A uint32 in pascals with a resolution of 0.1 Pa
  • 00002a6e-0000-1000-8000-00805f9b34fb Temperature (read, notify)
    • A sint16 in degrees Celsius with a resolution of 0.01 degrees Celsius
  • 00002a6f-0000-1000-8000-00805f9b34fb Humidity (read, notify)
    • A uint16 in percent with a resolution of 0.01 percent
  • 1e352f41-1217-5887-a357-c9acbd789b14 Luminance (read, notify)
    • A uint32 in Lux with a resolution of 0.01 Lux
• 1e352f00-1217-5887-a357-c9acbd789b14 Relay Service
  • 1e352f01-1217-5887-a357-c9acbd789b14 Relay State (read, write, notify)
    • A boolean value for getting and setting the relay state (on / off)
• 1e352f10-1217-5887-a357-c9acbd789b14 Switch Service
  • 1e352f11-1217-5887-a357-c9acbd789b14 Switch state (read, notify)
    • A boolean value describing the switch state (on / off)
• 1e352f20-1217-5887-a357-c9acbd789b14 Contact Sensor Service
  • 1e352f21-1217-5887-a357-c9acbd789b14 Contact Sensor State (read, notify)
    • A boolean value describing the contact sensor state (open / closed)
• 1e352f30-1217-5887-a357-c9acbd789b14 Motion Sensor Service
  • 1e352f31-1217-5887-a357-c9acbd789b14 Motion Sensor State (read, notify)
    • A boolean value describing the motion sensor state (open / closed)
• 1e352f50-1217-5887-a357-c9acbd789b14 RGB LED Service
  • 1e352f51-1217-5887-a357-c9acbd789b14 RGB LED Color (read, write, notify)
    • An array of 3 uint8 representing the R, G and B values of each LED, repeated per LED

The services and characteristic configuration for use with esp32-ble2mqtt is available at ble2mqtt_configuration.json

Configuration

There are two steps for configuration this project. The first is defining the SoC variant and the second is configuring the peripherals.

The SoC variant is defined the project's predefined symbols using TI's notation, one of: CC2650_LAUNCHXL, CC2650DK_7ID, CC2650RC, CC2650STK, BOOSTXL_CC2650MA, CC2650DK_5XD or CC2650DK_4XS

Configuring the peripherals is done the app/Startup/board.h file. There are macros for each peripheral to define the relevant GPIOs or I2C address. GPIO values use TI's IOID_X macros where X is the GPIO number. Use PIN_UNASSIGNED for GPIOs or 0 for I2C addresses when the peripheral is not used.

Below is a table summarizing the different peripheral options:

Peripheral	Macros	Type
Battery	Board_BATT_MIN, Board_BATT_MAX	Number (mV), number (mV)
Switch	Board_SWITCH	GPIO
Button	Board_BUTTON	GPIO
Contact sensor	Board_CONTACT	GPIO
OPT3001	Board_OPT3001_ADDR	I2C address*
BME280	Board_BME280_ADDR	I2C address*
Thermistor	Board_THERMISTOR_POWER, Board_THERMISTOR	GPIO (optional), ADC
Motion	Board_MOTION	GPIO
Relay	Board_RELAY_SET, Board_RELAY_RESET	GPIO, GPIO (optional)
LED	Board_LED1, Board_LED_ON, Board_LED_ON	GPIO, logic level, logic level
WS2812B	Board_WS2812_NUM_LEDS, Board_SPI0_MOSI	Number, GPIO (data line)

* When using I2C devices, you should also define Board_I2C0_SDA0 and Board_I2C0_SCL0 accordingly.

Increasing TX Power

When the device is running of mains power (EXCLUDE_BATT is defined) or when the MAX_TX_POWER preprocessor symbol is defined, the peripheral will transmit using the maximum power setting (either +2 or +5 dBm).

Security

By default, authentication is enabled requiring out-of-band pairing using a passkey before accessing one of the sensitive characteristics. If needed, this can be disabled by defining the DISABLE_AUTHENTICATION preprocessor symbol.

Compiling

The project is compiled and tested with TI's Code Composer Studio version 8.0.0. In addition, you need to install, in the default directory (C:\ti), TI's BLE stack version 2.2.2.

First, build the stack project and then the app project. Once both images are built, execute the create_image.py script. This script will create a unified image and also inject a random passkey. Make note of this passkey as you will need it to perform out-of-band pairing with the peripheral.

Note: If you can't or do not wish to make use of this script, you will need to set the passkey manually in app/Application/home_automation.c, look for 0xdeadbeef and replace that value with your chosen passkey. Then flash both the stack and app images on to your device.

Flashing

Flashing the CC2640 / CC2650 SoC can be done with the various XDS emulators, e.g. XDS100v3. Once connected, use TI's SmartRF Flash Programmer 2 to load the image.

Note: When flashing the stack and app images separately, make sure to erase only the sections in the image file and not the entire flash memory.