Why does my esp8266 just send transmit random characters?

My esp8266 is plugged into my arduino and just sends random characters to the serial monitor. It doesn't matter what baud I select and it does it constantly if the tx-cable is plugged in and the esp8266 has power. This didn't happen a few hours ago, but after i unsuccessfully followed a tutorial to try and connect it to wifi I went back just to check that i still could communicate using the serial monitor. And then it happened. Someone had the same problem it seems: arduino - esp8266 throwing random symbols when powered and not responding to AT commands - Electrical Engineering Stack Exchange, but they solved it by updating the firmware which seems to require a button on the esp8266 which isn't there.

what type of esp8266?
wha's the firmware on this ESP?

How have you connected everything ?

On an ESP-01 there isn't a dedicated 'flash' button. On a nodeMCU the 'flash button' is connected to GND & GPIO 0, If you then hold the button down while re-starting the ESP, it goes into flash mode. GPIO 0 can remain LOW while uploading (or be left free-floating after the reset and the boot mode has been set) So also a jumper wire would work just fine.
I have 2 buttons on my uploader.

  • One connecting RST to GND
  • One connecting GPIO 0 to GND

I press them both and first release RST and voila, Flash-mode.
Of course to make sure you know what you are doing, please answer JML's questions, show us the sketch you want to upload to what board, and what you are attempting to do in general. For the best advice we need all the information we can get.