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    BME688 development kit firmware compilation issue

    BME688 development kit firmware compilation issue



    trying to compile firmware for the 8x dev kit as described in:

    but running in the compilation issue:   

        Sketch uses 1375781 bytes (104%) of program storage space. Maximum is 1310720 bytes.

        Global variables use 62800 bytes (19%) of dynamic memory, leaving 264880 bytes for local variables. Maximum is 327680 bytes.
        Sketch too big; see for tips on reducing it.
        Error compiling for board Adafruit ESP32 Feather.


    Obviously, we are running out of the available HW resources.

    Any suggestions?

    11 REPLIES 11

    Community Moderator
    Community Moderator

    Hi fritz, 


    Could you downgrade ESP32 and RTClib? 

    ESP32 -  v2.0.3

    RTClib - v2.0.3

    Thank you. 

    Hi, Today I received my BME688 X8 Dev Board and ran into the same problem. The latest bme68x_demo_sample cannot be flashed on the ESP32 Feather because it is too big. (Sketch uses 1399613 bytes (106%) of program storage space. Maximum is 1310720 bytes.)

    Downgrading libraries only saves up a few bytes...

    Is a compacter release coming soon? Or is there a simple workaround rewriting (perhaps only commenting out) some files?

    The only flashable logging example is "bme688_dev_kit" from de BME68x Sensor Library, but that creates a .csv file which cannot be used in BME AI Studio. (I run that one now 24h to stabilize the sensor, is that okay, or will it generate too much heat and damage the sensors?)

    Community Moderator
    Community Moderator

    Could you check your lib version?

    You should use exact same version of lib as we guide. 


    Hi Minhwan, unfortunately that makes only a few bytes difference.

    Sketch uses 1399397 bytes (106%) of program storage space. Maximum is 1310720 bytes.

    • ArduinoJson (6.19.4)

    • RTClib (2.0.3)

    • SdFat (2.1.2)

    Compiled with Arduino IDE 2.0.3. But also Arduino IDE 1.8.13 results in same bytes count.

    So we need to shrink something down, or clever use the SDcard storage(!?) in a new bme68x_demo_sample.ino version.

    I got news! Using Board manager to downgrade ESP32 Espressif Systems to 2.0.3 gets it down to 1249317 bytes (95%) in Arduino IDE 1.8.13. (Arduino IDE 2.0.3 did not let me change the board library for now)

    That is not mentioned in the Quick Start Guide, but you mentioned it in a post earlier.