ok - made sure using 3.1 IDF - getting this on MKR 1010:
john@WEI-WS2 MINGW32 /c/esp/nina-fw
$ python /c/esp/esp-idf/components/esptool_py/esptool/esptool.py --chip esp32 --port COM17 --baud 115200 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size detect 0x0 NINA_W102.bin
esptool.py v2.5.0
Serial port COM17
Connecting....
Chip is ESP32D0WDQ6 (revision 1)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse
MAC: 84:0d:8e:34:62:20
Uploading stub...
Running stub...
Stub running...
Configuring flash size...
Auto-detected Flash size: 2MB
Compressed 1001472 bytes to 538027...
Writing at 0x0003c000... (48 %)Traceback (most recent call last):
File "C:/esp/esp-idf/components/esptool_py/esptool/esptool.py", line 2849, in
_main()
File "C:/esp/esp-idf/components/esptool_py/esptool/esptool.py", line 2842, in _main
main()
File "C:/esp/esp-idf/components/esptool_py/esptool/esptool.py", line 2594, in main
operation_func(esp, args)
File "C:/esp/esp-idf/components/esptool_py/esptool/esptool.py", line 2074, in write_flash
esp.flash_defl_block(block, seq, timeout=DEFAULT_TIMEOUT * ratio)
File "C:/esp/esp-idf/components/esptool_py/esptool/esptool.py", line 95, in inner
return func(*args, **kwargs)
File "C:/esp/esp-idf/components/esptool_py/esptool/esptool.py", line 616, in flash_defl_block
self.ESP_FLASH_DEFL_DATA, struct.pack('<IIII', len(data), seq, 0, 0) + data, self.checksum(data), timeout=timeout)
File "C:/esp/esp-idf/components/esptool_py/esptool/esptool.py", line 338, in check_command
val, data = self.command(op, data, chk, timeout=timeout)
File "C:/esp/esp-idf/components/esptool_py/esptool/esptool.py", line 306, in command
self.write(pkt)
File "C:/esp/esp-idf/components/esptool_py/esptool/esptool.py", line 269, in write
self._port.write(buf)
File "C:/msys32/mingw32/lib/python2.7/site-packages/serial/serialwin32.py", line 323, in write
raise writeTimeoutError
serial.serialutil.SerialTimeoutException: Write timeout