I am trying to program ESP01 module with cp2102 USB to TTL converter, I successfully programmed it earlier

Using logic level shifter i.e. resistor divider on RX and providing 3.3 v externally

My problem is when I try to program it now with same setup that worked earlier I see as code starts uploading my ESP01 and USB to TTL module lights blink but code doesn't get uploaded.

Could it be a problem related to the baud rate? If so, what can I do to solve that?

  • Have you tried totally powering it off? Is the ide showing any communication errors for the com port? Oct 2, 2020 at 18:59

1 Answer 1


Make sure to connect:

  • GPIO0 (pin #5) to GND (pin #1)
  • CH_EN (pin #4 - also called CH_PD) to VCC (pin #8 - 3.3v)

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