Unable to verify flash chip connection

  • Hi, everyone. I'm getting the following when I try to upload a sketch to my m5Stack Core Basic:

    Sketch uses 230493 bytes (17%) of program storage space. Maximum is 1310720 bytes.
    Global variables use 20968 bytes (6%) of dynamic memory, leaving 306712 bytes for local variables. Maximum is 327680 bytes.
    esptool.py v4.5.1
    Serial port /dev/cu.usbserial-556E0263581
    Chip is ESP32-D0WDQ6-V3 (revision v3.0)
    Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
    Crystal is 40MHz
    MAC: b0:b2:1c:51:83:80
    Uploading stub...
    Running stub...
    Stub running...
    Changing baud rate to 921600

    A fatal error occurred: Unable to verify flash chip connection (Invalid head of packet (0xE0): Possible serial noise or corruption.).
    Failed uploading: uploading error: exit status 2

    I searched this forum for this, and I'm not optimistic this will be an easy fix, since I don't see anyone else running into this.

    This is just a blank sketch.

    Any thoughts on how to get around this? I'm on a Mac. Thanks!

  • @hidarrin Might try a slower upload speed or a better cable.
    What sketch is currently running in the Core, right now?
    A blank sketch needs a delay, at least 100ms in the Loop or ideally a Serial print statement to test that the upload was in fact successful with the serial monitor.

  • @teastain Thanks for the reply.

    I've tried multiple cables. Some high-end ones. No change.

    The default sketch that ships on the Core was giving me this error, so I wiped with esptool, and same error.

    How do I slow the upload speed?

    Thanks again.


    I found the upload speed setting, and sure enough, that fixed it. Thanks!