micropython/(https://github.com/micropython/micropython.git)modules/bsec/
https://github.com/micropython/micropython/blob/master/ports/esp8266/README.md#build-instructions
Use esp-open-sdk in docker, from https://github.com/larsks/docker-image-esp-open-sdk
Use our own patch on top:
make -C esp-open-sdk-for-micropython # install 'esp-sdk' wrapper that forwards calls to docker, it mounts full $HOME docker run --rm -u $UID -v $HOME/bin:/target esp-open-sdk install-wrapper # usage https://github.com/larsks/docker-image-esp-open-sdk#wrapper-scriptcd micropython # get submodules for esp8266 port esp-sdk make -C ports/esp8266 submodules # build micropython cross compiler (<1min) esp-sdk make -C mpy-cross # patch micropython, cf https://github.com/devbis/st7789_mpy/#overflow-of-iram1_0_seg git apply ../0001-fix-iram1-overflow-move-bsec-text-to-irom0.patch# build port (~30s) cd micropython/ports/esp8266 #esp-sdk make clean esp-sdk make USER_C_MODULES=../../../modulesOutput (example):
Use make V=1 or set BUILD_VERBOSE in your environment to increase build verbosity. Including User C Module from ../../../modules/bsec ... LINK build-GENERIC/firmware.elf text data bss dec hex filename 661645 1016 67640 730301 b24bd build-GENERIC/firmware.elf Create build-GENERIC/firmware-combined.bin esptool.py v1.2 flash 34832 .text 31444 at 0x40100000 .data 1016 at 0x3ffe8000 .rodata 2332 at 0x3ffe8400 padding 2032 irom0text 627872 total 664736 md5 72bb9964e63979e5d79471410fb143b1 More build options:
- append
MICROPY_BSEC_DEBUG_VERBOSE=1to themakecommand to get debug logs of the BSEC module
Follow flash doc: https://github.com/micropython/micropython/blob/master/ports/esp8266/README.md#build-instructions
import machine import time import bsec i2c = machine.I2C(scl=machine.Pin(5), sda=machine.Pin(4), freq=100000) bme680 = bsec.BME680_I2C(i2c) bme680.init() while True: measurement_timestamp_ns = time.time_ns() bme680.force_measurement(measurement_timestamp_ns) delay_us = bme680.get_read_data_delay_us() time.sleep_us(delay_us) data = bme680.read_data(measurement_timestamp_ns) print(data) next_call_timestamp_ns = bme680.get_next_call_timestamp_ns() delay_us = max(next_call_timestamp_ns - time.time_ns(), 0) // 1000 print("sleep (in s)", delay_us/1000000) time.sleep_us(delay_us) # example output: # {'iaq': 144.758, 'staticIaqAccuracy': 3, 'gasResistance': 171795.0, 'rawHumidity': 49.9882, 'co2Accuracy': 3, 'breathVocAccuracy': 3, 'staticIaq': 103.249, 'iaqAccuracy': 3, 'breathVocEquivalent': 1.63182, 'co2Equivalent': 1032.49, 'humidity': 65.8691, 'pressure': 100328.0, 'temperature': 24.1201, 'rawTemperature': 28.7868} # After iaqAccuracy reaches 3, i.e. calibrated: # Save state calibrated_state = bme680.get_state() # Save to persistent memory state_filename = 'bsec_bme680_calibrated_state.bin' with open(state_filename, 'wb') as f: wrote = f.write(calibrated_state) print('wrote', wrote, 'bytes on file', state_filename) # Load from persistent memory with open(state_filename, 'rb') as f: calibrated_state = f.read() print('read', len(calibrated_state), 'bytes on file', state_filename) # Restore bme680.set_state(calibrated_state)(see BSEC_1.4.8.0_Generic_Release/integration_guide/BST-BME680-Integration-Guide-AN008-48.pdf)
- expose the sensor once to good air (e.g. outdoor air) and bad air (e.g. box with exhaled breath) for auto-trimming.
- wait for
accuracyto reach3 - save calibration state:
- connect with
screen - CTRL-C
sensors_bme680_save_state(sensor_bme680)- reset board
- connect with
Some resources that helped:
- https://docs.micropython.org/en/latest/develop/cmodules.html
- https://micropython-usermod.readthedocs.io/en/latest/index.html
- https://forum.micropython.org/, various posts to better know external C modules, also notably https://forum.micropython.org/viewtopic.php?t=9703 to better understand the libmath linking issue
- https://github.com/devbis/st7789_mpy/ real example, notably with the iram1 overflow
- https://github.com/BoschSensortec/BSEC-Arduino-library
- https://www.bosch-sensortec.com/software-tools/software/bsec/ Integration Guide pdf
- https://community.bosch-sensortec.com/t5/Bosch-Sensortec-Community/ct-p/bst_community, notably https://community.bosch-sensortec.com/t5/MEMS-sensors-forum/BME680-on-LPC845-using-Bosch-s-BSEC-library/m-p/17717 to better understand the libmath linking issue