I am using an external power supply for the chip and using Arduino as a serial converter. All this set up works fine to send commands to the ESP but as soon as I connect the GPIO0 to GND and boot it in firm upload mode. It just wont respond to anything. Under normal operation every command sent to it lights up the blue LED but in firmware update mode blue LED never lights up.
I have tried so many ways to see if I am doing something foolish. Rewired it , changed power supplies , changed my computer but nothing seems to work. btw I have the GND of Arduino & ext supply of ESP connected together.
Please note that in the regular boot mode the chip is working perfect except that it hangs and outputs junk characters sometimes, although the Web LED example works fine even when this situation happens.
Any idea from anybody would be of help - I have spent the entire day with no result.