For example:
python esptool.py -p com33 erase_flash
python esptool.py -p com33 flash_id
python esptool.py -p com33 -b 115200 write_flash -ff 80m -fm dio -fs 1MB 0x0 boot_v1.7.bin 0x01000 firmware.bin
Yeilds:
at the command prompt and
PORT OPEN 74880
Communication with MCU..Got answer! Communication with MCU established.
AutoDetect firmware...
Can't autodetect firmware, because proper answer not received (may be unknown firmware).
Please, reset module or continue.
boot mode:(3,6)
load 0x40100000, len 2592, room 16
tail 0
chksum 0xef
load 0x00000000, len 0, room 8
tail 0
chksum 0xef
load 0x00000000, len 0, room 0
tail 0
chksum 0xef
csum 0xef
csum err
ets_main.c
at the ESPlorer.
I have tried various combinations of baud rate, write speed, dio / qio and flash sizes and all give the same result. In the case above the firmware.bin is my custom firmware which works on the esp8266 but I have also tried various demo firmwares from around the web.
Finally, if I try and run the esptool.py against one of my working NodeMCU units it times out with a no packet header error.
Can anyone point me in the correct direction here?