ESP8266 Community Forum

- Sun Jun 07, 2015 12:18 am #19715 Hi Sexum,
I found your post interesting. How do I know if my ESP has the firmware or not, if I can not even talk to it yet? I only have Adriuno, not the USB-serial converter yet. Is there anyway the flushing can work ? or do I need to wait.

I am sending it AT+RST and get something that looks like "byyby, or yyyyy" for response. Thanks,

Chang Liu

- Sun Jun 07, 2015 2:18 am #19718 serial speed mismatch?

- Tue Jun 16, 2015 3:44 am #20575 Ok. Three things which you might have missed.

1. The Ground from the Arduino has to connected to the Ground of the External power supply that you use to power the esp8266 chip(3.3v)

2. Use a voltage divider or a level converter(better) to convert 5v from arduino tx to 3.3v for esp. If not, you are just waiting for the bad to happen.

3. Finally the baud rate at which the device is setup may be different from the one you are using in the code. I assume teh default ones come with 115200. So you may have to set to the same baud rate to get results.

Finally you may need a Mega to send data via the IDE to the unit ,for AT+RST commands.

- Tue Jun 16, 2015 11:13 am #20603

I also spent a lot of time before get it working.

1) have a GOOD power supply (400ma at least)

Yes, definitely do not try to power it off the USB or the 3.3v output on the Arduino. (Or the 5v off the Arduino, even if stepped down it will not have the current.) be sure to tie the grounds of the two supplies together.

Note that if you have a solid 5v supply that is already regulated then you should be able to power the Arduino by feeding this IN to the 5v pin. The Arduino will want 7v or more if you feed in to its VCC input. But if you have one 5v regulated supply, and a step down to 3.3v for the ESP you can make it work (not sure if I ever did this on an Uno, but I have on Nanos).

5) the ESP8266 emits a lot of RF interferences that may create problems to arduino: try to shield the ESP8266 with some conductive plate connected to ground (be sure to not touch any contact of the ESP8266 with the conductive plate)

Do you have any more info (pics / diagrams) on this? I have been thinking of trying to shield these ESP-01s better. I am using them on their own, with C code from the IDE, but I still have RF issues sometimes. I wondered if putting some kind of shield over the chips would help, like the 07 and 12 models have.

6) if you are using a 5v arduino you have to level shift the tx line (I'm using a zener diode + resistor)

These level shifters work great in both directions and are cheap. Each one does four pins, IIRC.

http://www.ebay.com/itm/181572335264?_t ... EBIDX%3AIT