ESP8266 Community Forum

- Tue Feb 23, 2016 7:50 am #41713 Hi

I used one esp01 with DHT22 for temperature and humidity log. I use arduino sketch. No problem to upload sketch.

I received last week some esp12e. I try to upload sketch, no problem but DHT access doesn't work. It's another problem.

Sunday, i was connect to my esp01 when i disconnect DHT (power was on). After that, my sketch doesn't work anymore. So i try to reupload it, upload work nice but every time i power on, i only see strange caracter on serial monitor. My sketch doesn't work.

I try the same with my esp12e but i only see strange caractere too, none of the example sketch work.

So i try to upload original firmware but i have : "Failed to write to target Flash" or "Invalid head of packet".

I don't know what to do, i don't think it's my ftdi adaptater because i can upload sketch.

If someone has a solution

- Thu Feb 25, 2016 1:57 pm #41881 Any idea how to factory reset esp ?

- Thu Feb 25, 2016 2:23 pm #41883 There is no such "factory defaults" !
The Flash can even be emptied using the esptool.py

Code: Select allesptool.py --port /dev/ttyUSB0 erase_flash

You should be able to upload any thing using FTDI, if you get those errors, it is either wiring problems, power supply problems or FTDI problems.
Just make sure to have GPIO0 and GPIO15 pulled down and GPIO2/CH_PD/RES pulled up.

- Sat Feb 27, 2016 5:47 am #41989 I try with a new esp12e, i can upload arduino sketch but nothing happen next. Sketch doesn't work, only strange line on serial monitor.

Do you think it can be a problem with ftdi ?