Issues with the T7-S3

alveron

Hi
Recently purchased the T7-S3, have a few observations, want to know if this is the norm or I am down a path I should not be.

Connecting the unit to the Auduino IDE seems to go ok at the start, select the board and the com port fine, however when I press the restart button the IDE loses the comm port and I have to select it again ? If I try to upload a sketch I get this error

Sketch uses 244698 bytes (18%) of program storage space. Maximum is 1310720 bytes.
Global variables use 16084 bytes (4%) of dynamic memory, leaving 311596 bytes for local variables. Maximum is 327680 bytes.
esptool.py v4.5.1
Serial port COM15
Connecting....

A serial exception error occurred: Write timeout
Note: This error originates from pySerial. It is likely not a problem with esptool, but with the hardware connection or drivers.
For troubleshooting steps visit: https://docs.espressif.com/projects/esptool/en/latest/troubleshooting.html
Failed uploading: uploading error: exit status 1

What does pressing the reset and boot at the same time do ? If I do this first, the sketch uploads and runs fine, but I need to restart first, and none of the Serial.println messages are written to the serial monitor?? So I am confused, the error message says possible hardware error, but I can upload after pressing the reset and boot fine, same hardware ??
The schematic shows that I can read the battery voltage on IO2, this is through a voltage divider of 100K each so the voltage read should be doubled to get the right reading. When I try this I get about half of what is expected and it never changes, even as the battery drops the reading stays the same? Doesn't seem to be working.

Thanks in advance..

alveron

@alveron
Update
re 1. I tried a second machine and am able to upload a sketch without having to do any button presses, however I am still not getting any communication back through the serial monitor. When I run a sketch I can see the boot messages but no messages generated from within by the sketch.

teastain2

@alveron Sometimes...this depends on the sketch that is running and other Arduino environment conditions...you need to manually enter Upload Mode.
Press both Reset and Boot and release the reset first. You will lose the Arduino serial com and you need to re-select it.
Once you have a stable environment it may not require the sequence, just Upload!
You must select USB CDC On Boot: "Enabled" to get serial from your sketch to your computer.
ADC in ESP32 is very poor. I don't have a T7-S3 to test, just check the Diagram and other Internet sources. There will be data noise and poor accuracy.