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By JJ Goh
#77623 I am new to arduino and receive my arduino set during weekend. I have a ESP 8266 01

Initially I connect it via 3.3 V on arduino UNO ( which I found out it is not recommended) and did not step down 5v TX or RX pin to 3.3v
I did get respond with AT command. I able to connect to the WiFi.
I the meanwhile I did change the baud rate from 115200 to 9600 and switch it back
I did upload blink sketch to ESP 8266, keep getting error regarding EPOM but eventually i able to upload it. But blue light did not blink. (without step down RX voltage)

Now ESP 8266 didnt respond to at command and I am unable to detect the WiFi. It did send garbage message which I cannot read to the serial monitor when it power up.
It respond to ESPFlashDownloadTool and I able to flash the firmware ( I was thinking it like an iPhone, flash it with official firmware able to solve the problem)
I know it might sound stupid,
I connect 5v power source (arduino) and adjust a potential meter with multimeter to supply 3.3V
Create a voltage divider for RX pin


What should I do now to make it work again ?
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By PtrO
#77648 Good news, as you can up/download firmware; the esp01 does not looked to be bricked. The bootloader proces is (still) operational. Perhaps/likely you've wiped the "AT" command firmware.

In case overpowering the esp8266 some (connected) GPIO pins might burned out and could make the device functionally unusable. Getting garbage form serial, try other baudrate speeds/settings.

The best thing you can do is either reload your "AT" firmware or use your own Arduino-IDE/esp8266 sketch.
See for some resource: https://www.electrodragon.com/w/ESP8266_AT-Command_firmware. During this process, do no forget toe wipe the flash as settings may else be remembered. Of course you can reload some other firmware.

Personally, I would program/compile/load my own firmware using the Arduino-IDE in esp8266 mode.