Instructions for using the BSEC Arduino Library in Arduino 1.8.16

About BSEC

Bosch Sensortec Environmental Cluster (BSEC) Software v2.0.6.1 released on April 30th, 2021

The BSEC fusion library has been conceptualized to provide a higher-level signal processing and fusion for the BME688. The library receives compensated sensor values from the sensor API. It processes the BME688 signals to provide the requested sensor outputs.

Key features

• Selectivity to target gas classes
• Calculation of index for air quality (IAQ) level outside of the device
• Calculation of ambient air temperature outside of the device (e.g. phone)
• Calculation of ambient relative humidity outside of the device

Typical applications

• Indoor air quality
• Home automation and control
• Internet of things
• Weather forecast
• GPS enhancement (e.g. time-to-first-fix improvement, dead reckoning, slope detection)
• Indoor navigation (change of floor detection, elevator detection)
• Outdoor navigation, leisure and sports applications
• Vertical velocity indication (rise/sink speed)

Supported platforms

• BSEC library is supported on 32, 16 and 8 bit MCU platforms

Available binaries for download:

Platform	Compiler	ROM (BSEC)	RAM	TYPE
Cortex-ARM	ARMCC	24.22-25.72k	4.38k	Cortex-M0, M0+, M3, M4, M4_FPU, M7
Cortex-ARM	GCC	27.22-49.45k	4.38k	Cortex-M0, M0+, M3, M4, M4_FPU, M7
Cortex-ARM	IAR	27.05k-27.73	4.38k	Cortex-M0, M0+, M3, M4, M4_FPU, M7
Cortex-A*	GCC	28.20-33k	4.38k	Cortex-A7, Cortex-A73
AVR_8bit	AVR-GCC	56.8-57.8k	39.61k	MegaAVR, XMEGA
AVR_32bit	AVR-GCC	31.99k	4.5k	32-bit AVR UC3
ESP8266	xtensa-lx106-elf-gcc	36.24k	4.39k	ESP8266
ESP32	xtensa-esp32-elf-gcc	31.84k	4.39k	ESP32
MSP430	msp430-elf-gcc	45k	3.97k	MSP430
Android system-x86	gcc	46.93-44.72k	4.48k	x86, x86_64
Android system-arm	gcc	51.9k	4.43k	arm, arm64
Raspberry PI 0 linux	arm-linux-gnueabihf-gcc	75.36k	4.39k	armv6-32bits
Raspberry PI3 linux	arm-linux-gnueabihf-gcc	75.38k	4.39k	armv8-a-64bits

The library size information above doesn't include additional dependencies based on the embedded system project & platform.

For other platforms, please contact your local Bosch Sensortec representative

Advantages

• Easy to integrate
• Hardware and software co-design for optimal performance
• Complete software fusion solution out of one hand
• Eliminates need for own fusion software development
• Robust virtual sensor outputs optimized for the application

Software license agreement

The BSEC software is only available for download or use after accepting the software license agreement. By using this library, you have agreed to the terms of the license agreement.

BSEC license agreement

Installation and getting started

1. Install the latest Arduino IDE

As of this publication, the latest Arduino IDE 1.8.16 can be downloaded from this link

2. Install the BSEC library

Download this library as a zip and import it into the Arduino IDE. Refer to this guide on how to import libraries.

3. Install the BME68x library

• Download the Arduino library "Bosch_BME68x_Library" from here. This library is a dependency for using the BSEC library.

4. Install esp32 Board package in the Arduino IDE

• Open File->Preferences->Settings

• Insert the following link into the "Additional Boards Manager URLs":

  https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json

  Note: Please ensure that the proxy settings are updated under File->Preferences->Network

• Go to Tools->Board->Boards Manager and search for "esp32"

• Install the esp32 package

5. Modify the platform.txt file under esp32 package

If you have already used the previous example code and hack guide, remove the linker flag -libalgobsec in the platform.txt file and reference to the compiler.c.elf.extra_flags.

The standard arduino-builder now passes the linker flags under compiler.libraries.ldflags. Most platform.txt files do not already include this new optional variable. You will hence need to declare this variable's default and add it to the end of the combine recipe. It is recommended to declare it in the following section like below,

# These can be overridden in platform.local.txt
compiler.c.extra_flags=
compiler.c.elf.extra_flags=
#compiler.c.elf.extra_flags=-v
compiler.cpp.extra_flags=
compiler.S.extra_flags=
compiler.ar.extra_flags=
compiler.elf2hex.extra_flags=
compiler.libraries.ldflags=

and add it in the combine recipe like the below examples

ESP32 community forum's ESP32 core

Original line 151,

## Combine gc-sections, archives, and objects
recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" "-Wl,--Map={build.path}/{build.project_name}.map" "-L{compiler.sdk.path}/lib" "-L{compiler.sdk.path}/ld" {compiler.c.elf.flags} {compiler.c.elf.extra_flags} {build.extra_flags} -Wl,--start-group {object_files} "{archive_file_path}" {compiler.c.elf.libs} -Wl,--end-group -Wl,-EL -o "{build.path}/{build.project_name}.elf"

should become

## Combine gc-sections, archives, and objects
recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" "-Wl,--Map={build.path}/{build.project_name}.map" "-L{compiler.sdk.path}/lib" "-L{compiler.sdk.path}/ld" {compiler.c.elf.flags} {compiler.c.elf.extra_flags} {build.extra_flags} -Wl,--start-group {object_files} "{archive_file_path}" {compiler.c.elf.libs} {compiler.libraries.ldflags} -Wl,--end-group -Wl,-EL -o "{build.path}/{build.project_name}.elf"

ESP8266 community forum's ESP8266 core

Original line 122,

## Combine gc-sections, archives, and objects
recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" {build.exception_flags} -Wl,-Map "-Wl,{build.path}/{build.project_name}.map" {compiler.c.elf.flags} {compiler.c.elf.extra_flags} -o "{build.path}/{build.project_name}.elf" -Wl,--start-group {object_files} "{archive_file_path}" {compiler.c.elf.libs} -Wl,--end-group  "-L{build.path}"

should become

## Combine gc-sections, archives, and objects
recipe.c.combine.pattern="{compiler.path}{compiler.c.elf.cmd}" {build.exception_flags} -Wl,-Map "-Wl,{build.path}/{build.project_name}.map" {compiler.c.elf.flags} {compiler.c.elf.extra_flags} -o "{build.path}/{build.project_name}.elf" -Wl,--start-group {object_files} "{archive_file_path}" {compiler.c.elf.libs} {compiler.libraries.ldflags} -Wl,--end-group  "-L{build.path}"

5. Verify and upload the example code

Start or restart the Arduino IDE. Open any of the example codes found under Bosch_BSEC2_Library>examples.

Select your board and COM port. Upload the example. Open the Serial monitor. You should see an output on the terminal.

More about example codes:

• basic.ino: This is an example for illustrating the basic BSEC virtual outputs.

• basic_config_state.ino: This is an example for illustrating the BSEC feature using desired configuration setting.

• bme68x_demo_sample.ino: This demonstrator application running on an x8 board has the feature of sensor data logging and BSEC algorithm illustrated. Please refer BME688 Development Kit-Firmware-Quick-Start-Guide for installing dependent libraries and how to flash.

6. Tested board/core list

The current list of tested boards include,

Core MCU	Tested boards	Arduino core version	Arduino core repository
Esp32	Adafruit ESP32 Feather	v2.0.1	https://github.com/espressif/arduino-esp32
Esp8266	Adafruit Feather HUZZAH ESP8266	v3.0.2	https://github.com/esp8266/Arduino

Copyright (C) 2021 Bosch Sensortec GmbH. All rights reserved.