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Initial Serial Communication with the ESP8266-01

PostPosted: Sat Feb 27, 2016 10:18 am
by Eugene S
Hello everyone,

For the past few days I have been trying to get my esp chip working without any luck whatsoever, so I decided to post here for help.

What I am currently trying to do is included as something basic in almost every guide online yet for some reason it does not for me. I am trying to communicate with the esp using the serial port (have tried arduino's monitor & coolTerm) and the closest I have gotten so far is this: http://puu.sh/nnjiY/4cc3355214.png. As you can see, I get flooded by "1"s and I am unable to submit any command (for example a simple "AT") as it doesn't listen.

Note that i am using the arduino UNO itself to get serial access (tx/rx pins) to the esp chip and not some USB to TTL converter. I have tried few slightly different pin connections I have found online, yet none of them seems to be working for me (Including both having an external 3.3V source and arduino's 3.3V supply). Here is one of them from electronut: http://electronut.in/images/2014/12/esp8266-circuit.jpg where VCC, Tx, Tx and GND are the corresponding arduino pins.

After some research I have also downgraded to 1.6.5 arduino IDE, have included the .json file in the board manager and have selected the "Generic ESP8266 Module" (don't know If that matters at all during my stage, as I am only trying to communicate serially without uploading any software and coolTerm has the same result as well).

After all these days I either still do something terribly wrong or something is just broken, in any case I am quite desperate for any help I can get from you.

Re: Initial Serial Communication with the ESP8266-01

PostPosted: Sat Feb 27, 2016 2:41 pm
by schufti
Eugene S wrote:Note that i am using the arduino UNO itself to get serial access (tx/rx pins) to the esp chip and not some USB to TTL converter.

bad idea, why do ppl allways choose the hardway first if they don't have any experience yet???
At least you should have an UNO with DIP µC and taken it out of the socket. Alternatively you can apply RST and hold it active. Reason: USB-serial converter on UNO can only communicate with µC OR esp, not with both in parallel.
The voltage divider on UNO Tx isn't really necessary, 10k in series should be save enough (500µA should be acceptable for protection diodes in esp). The 3.3V regulator on UNO should be ok for first experiments. Could be adviseable to place small electrolytic on esp.

Eugene S wrote:After all these days I either still do something terribly wrong

YES...being terribly cheap and saving US$2 where it doesn't make sense

Go buy an USB-serial converter with CP2102, it's 3.3V output - backed by small electrolytic - proved to be good enough for general esp operation and saves you from days of headache .... obviously money well invested.

Re: Initial Serial Communication with the ESP8266-01

PostPosted: Sun Feb 28, 2016 12:44 am
by Eugene S
schufti wrote:
Eugene S wrote:Note that i am using the arduino UNO itself to get serial access (tx/rx pins) to the esp chip and not some USB to TTL converter.

bad idea, why do ppl allways choose the hardway first if they don't have any experience yet???
At least you should have an UNO with DIP µC and taken it out of the socket. Alternatively you can apply RST and hold it active. Reason: USB-serial converter on UNO can only communicate with µC OR esp, not with both in parallel.
The voltage divider on UNO Tx isn't really necessary, 10k in series should be save enough (500µA should be acceptable for protection diodes in esp). The 3.3V regulator on UNO should be ok for first experiments. Could be adviseable to place small electrolytic on esp.

Eugene S wrote:After all these days I either still do something terribly wrong

YES...being terribly cheap and saving US$2 where it doesn't make sense

Go buy an USB-serial converter with CP2102, it's 3.3V output - backed by small electrolytic - proved to be good enough for general esp operation and saves you from days of headache .... obviously money well invested.



Buying a serial converter is on my Monday to-do list now. (it's not about being cheap, i have more than enough money, it was about figuring how to achieve things without having to retreat to the easy way after a few bumps)

I will report back on Monday when it should hopefully be working. Thanks for your reply.