I try to upload simple sketch on heltec wireless stick(https://heltec.org/project/wireless-stick/), and got this error
"Sketch uses 706609 bytes (21%) of program storage space. Maximum is 3342336 bytes.
Global variables use 37984 bytes (11%) of dynamic memory, leaving 289696 bytes for local variables. Maximum is 327680 bytes.
esptool.py v3.3-dev
Serial port /dev/ttyUSB0
Connecting…
A fatal error occurred: Failed to connect to ESP32: No serial data received.
For troubleshooting steps visit:
Failed uploading: uploading error: exit status 2"
any suggestion how to fix it?