<![CDATA[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
Connecting.....
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
Changed.

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!

]]>https://community.m5stack.com/topic/5774/unable-to-verify-flash-chip-connectionRSS for NodeMon, 20 Apr 2026 09:08:16 GMTSat, 04 Nov 2023 20:14:24 GMT60<![CDATA[Reply to Unable to verify flash chip connection on Tue, 03 Jun 2025 11:37:33 GMT]]>Try lowering the baud rate to 115200 in the upload settings—921600 can sometimes cause issues, especially on macOS. Also, double-check your USB cable (some are power-only), and try a different USB port or hub. If you're using a USB-C to serial adapter, that might be causing noise.

]]>https://community.m5stack.com/post/29193https://community.m5stack.com/post/29193Tue, 03 Jun 2025 11:37:33 GMT<![CDATA[Reply to Unable to verify flash chip connection on Sun, 05 Nov 2023 13:36:14 GMT]]>SOLVED:

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

]]>https://community.m5stack.com/post/22657https://community.m5stack.com/post/22657Sun, 05 Nov 2023 13:36:14 GMT<![CDATA[Reply to Unable to verify flash chip connection on Sun, 05 Nov 2023 13:32:55 GMT]]>@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.

]]>https://community.m5stack.com/post/22656https://community.m5stack.com/post/22656Sun, 05 Nov 2023 13:32:55 GMT<![CDATA[Reply to Unable to verify flash chip connection on Sat, 04 Nov 2023 23:54:08 GMT]]>@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.

]]>https://community.m5stack.com/post/22652https://community.m5stack.com/post/22652Sat, 04 Nov 2023 23:54:08 GMT