Mod a USB to TTL Serial Adapter (CP2102) to Program ESP8266





Introduction: Mod a USB to TTL Serial Adapter (CP2102) to Program ESP8266

This USB to TTL Serial board based on the CP2102 chip, it have no enough current (400mA+) to driven ESP8266. So I will fix the issue.

CP2102 Datasheet:

UPDATE: I made a new CP2102 USB to TTL converter depend on the board. It's now on tindie.

Step 1: Materials

  • 1 x CP2102 USB adapter, it's easy be found at eBay by keyword cp2102
  • 1 x AMS1117-3.3
  • A knife
  • A soldering iron

Step 2: Cutting Off the Original 3.3V Output

The 3.3V from CP2102 has only 200mA output. It's not enough for esp8266. I cutting off the 3.3V output with an knife.

Step 3: Soldering LDO AMS1117-3.3

Use the pin 5V as input of AMS1117, connect the output to 3.3V

Now the USB adapter can driven esp8266 directly.



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    21 Discussions

    I'm using old Profilic PL2303 USB2TTL adapter with dual 3.3V and 5V outputs.
    On 3.3V pin flashing ESP without external power is ok ;) Tested with ESP-01, ESP-12E, ESP-14 and LUA MCU Dev Board V3.

    If you have only 5V output, so this mod can work. BR

    Does old prolific driver work with Windows 10? Bought one and no any text on the chip, couldn't make it work yet :(

    It is working, but with only one old Profilic driver ... drivers from Windows Update or automaticaly installed drivers doesn't work. (the exclamation mark in HW manager)

    I've saved it for later use, here is link from my dropbox:

    Please don't forget to check it with antivirus SW before running it!
    I've installed this many months ago, BR ;)

    Thanks kubik256 your driver works fine.

    I didn't know I can draw enough current from the chip on 3.3v
    I'll try.

    Hmmm aren´t the TR/RX wires from the CP2102 5V too?

    So they are able to destroy the ESP aren´t they?

    I am using ESP8266 with CP2102. For ESP8266 supply I am using LD33v connected to VCC and CH_PD. as soon as serial monitor is open it shows continuous garbage value which is never ending. How to solve this issue?

    2 replies

    Hi yanc, For ESP supply I used LD33v output which is 3.3 v and can handle 1A current.


    3 years ago

    You can found the driver here


    3 years ago

    Hello, please search ebay for cp2102, you will find a lots of board like the image.

    1 上午10:49.jpg