ESP8266 Community Forum

- Tue Dec 29, 2015 7:33 am #37373 Sorry that you are having difficulty getting the board to work. As I said in my initial response, "If I am reading the datasheet for your USB/Serial board correctly, the EDHSP looks like it is putting out 5V at 200 mA and that is probably insufficient (It does look like the I/O pins are 3.3v so that is good). I would not use it to power the board."

In your latest diagram, however, it looks like you are using your USB/Serial board to power the board - so that alone could be one reason why it does not work.

You should not have to directly connect to the pins around the chip to flash the board. You should only need sufficient power, ground, TX and RX.

- Sun Jan 03, 2016 3:18 am #37760 As stated several times:
The Rx/tx lines MUST be 3.3 V only !

In my case the USB sends out a 5V signal.

If the input current somehow is not limited the pin may burn out, which happened in my 1st experiment with the ESP.

A serial resistor around 1kOhm vil limit the input to the ESP which apparently has a clamp diode on the pin.

(Maybe there are clamp diodes on all pins ? I haven't tested)

Actually I have applied serial resistor into both lines Rx/tx to avoid a mishap while swapping the Rx/tx lines during system setup.

Also note that LUA will be erased by your 1st successful flash.

- Mon Jan 11, 2016 11:00 pm #38553 HI,
how did it go?
i'm facing the same situation here, i can see all messages from the board but it doesn't recognize any AT commands. I can use the app from Android, IoT manager, that works but does not what i want.

If you get this thing working tell me how! please!

thank you very much!
Max

- Wed Jan 13, 2016 11:11 am #38690 Hi, just wanted to post i did flash the ESP as i mention in this other post: http://www.esp8266.com/viewtopic.php?f=13&t=7224&p=38689#p38689

thanks!
Maxi