ESP8266 Community Forum

- Fri Jul 31, 2015 2:00 am #24671 Hi, i am having a huge problem and I dont know how to solve it. I have crushed 3 esp07 boards.
Instead of using an uart adapter, I use an arduino uno to boot the esp07 (I remove the arduino's processor previously) and a mb102 protoboard power supply for the esp (The power supply is
the following: http://www.ebay.com/itm/MB102-Breadboar ... 27c9a49d58)

Connections are
RX --- RX (arduino) (No need to connect RX-TX )
TX ---TX (arduino)
GND --- GND
CHPD --- VCC (mb102)
VCC (ESP) --- VCC (mb102)
GPIO0 --- GND
GPIO15 --- GND
GPIO2 --- VCC (mb102)

I join the arduino's and the esp's gnd with the mb102's gnd.
At first, it works great, but the board gets really warm. After several uses, the board red light becomes weak. Then, when I connect the esp with the mb102, mb102's light becomes weak also, and the esp won't work. This happened also with esp01 and esp12.
Does anyone knows what can possibly be wrong? Maybe the mb102? The connections between esp and arduino shoul be connected with resistors?

Thanks for your time, and sorry for my english.

- Fri Jul 31, 2015 4:55 am #24684

Instead of using an uart adapter, I use an arduino uno to boot the esp07 (I remove the arduino's processor previously) .

If you are programming through the Arduino then that implies the serial terminal is sending signals through the USB to the arduino's USART then on to the ESP8266. Now I don't understand that as I have never done that. The ESP8266 can be connected direct via an FTDI cable as you know which is how I do it .

Wouldn't the signals on TX and RX be 5 volt from the usb connection? I have 1K resistors in my RX and TX lines anyway and I might suggest doing the same on yours perhaps and using a voltage divider . I don't understand why the TX/RX do not need to be crossed either doing it that way whereas the direct ftdi cable must be crossed . perhaps the lines are crossed on the Arduino board. What affect on those lines does taking the processor out have.

Last edited by tytower on Fri Jul 31, 2015 5:25 pm, edited 3 times in total.

Get you modules here:

https://www.banggood.com/custlink/KvGGhGF4wG

- Fri Jul 31, 2015 6:30 am #24690 You are using a 5v arduino to flash a 3.3v Esp8266.
Get a 3.3v usb to serial adapter. Or a level shifter
Sticking a resistors between them isnt going to make it right.
Unless you use them as a voltage devider and make your own level Shifter.

Keeping a few usb to serial adapters in your kit of parts is useful anyway and they are cheap.
Some of the best come with both 5v and 3.3v broken out which can be useful.

Gordon

- Fri Jul 31, 2015 6:41 am #24691 If your Arduino or USB adapter is 5V, you MUST use level shifters. The ESP is 3.3V and has 3.3V inputs are not 5V 'friendly'. I use several ESP-07 and ESP-01 boards running at 3.3V using level shifters to a 5V USB adapter and still works fine, never bricked one.