Divide by zero exception esptool.py v3.0 (ESPTOOL-433)

[owenduffy]

Operating System

Win10

Version

latest master

Python Version

3.9

Chip Description

Esp8266

Device Description

esp01s

Hardware Configuration

No response

How is Esptool Run

Windows command window

Full Esptool Command Line that Was Run

D:\Users\owen\AppData\Local\Programs\Python\Python39\scripts\esptool.exe -c ESP8266 -b 921600 -p com8 read_flash 0xfe000 0x80 wifisettings.bin

Esptool Output

D:\src\EspRelay>D:\Users\owen\AppData\Local\Programs\Python\Python39\scripts\esptool.exe -c ESP8266 -b 921600 -p com8 read_flash 0xfe000 0x80 wifisettings.bin
esptool.py v3.3
Serial port com8
Connecting...
Failed to get PID of a device on com8, using standard reset sequence.
.
Chip is ESP8266EX
Features: WiFi
Crystal is 26MHz
MAC: a4:cf:12:b9:80:27
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 921600
Changed.
128 (100 %)
128 (100 %)
Traceback (most recent call last):
  File "D:\Users\owen\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "D:\Users\owen\AppData\Local\Programs\Python\Python39\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "D:\Users\owen\AppData\Local\Programs\Python\Python39\scripts\esptool.exe\__main__.py", line 7, in <module>
  File "D:\Users\owen\AppData\Local\Programs\Python\Python39\lib\site-packages\esptool.py", line 5380, in _main
    main()
  File "D:\Users\owen\AppData\Local\Programs\Python\Python39\lib\site-packages\esptool.py", line 4812, in main
    operation_func(esp, args)
  File "D:\Users\owen\AppData\Local\Programs\Python\Python39\lib\site-packages\esptool.py", line 4267, in read_flash
    % (len(data), args.address, t, len(data) / t * 8 / 1000), last_line=True)
ZeroDivisionError: float division by zero

More Information

Divide zero exception... possibly due to calculation of transfer speed for short file at high speed giving a time of zero. Needs try/catch ... and in any event, it does not make sense to calculate transfer speed if the total time is less than say 10 times the minimum time increment.

Other Steps to Reproduce

No response

I Have Read the Troubleshooting Guide

• I confirm I have read the troubleshooting guide.

[radimkarnis]

Hi @owenduffy,
thanks for reporting this.

We will patch this soon. Or if you feel like it, we welcome contributions!

[owenduffy]

The simplest fix might be at line 4266 of esptool.py (7e3496d), change:

    print_overwrite('Read %d bytes at 0x%x in %.1f seconds (%.1f kbit/s)...'
                    % (len(data), args.address, t, len(data) / t * 8 / 1000), last_line=True)

to:

    try
        print_overwrite('Read %d bytes at 0x%x in %.1f seconds (%.1f kbit/s)...'
                    % (len(data), args.address, t, len(data) / t * 8 / 1000), last_line=True)
    except
        pass

Not tested though.

Owen