ESP8266

Ahh, great, thank you guys for the information. I mainly wanted to just run some tests with one of these chips. Right now all my sensor nodes use RFM12B's with an attiny85. All the nodes work great and the power saving features of the both these chips is very good, coin batteries last a long time(over a year now).

While my sensor nodes are small, I wish I could get them even smaller, I have a plant water level sensor, but I used an old walwart housing for it. All the components fit snug, but it's very noticeable next to the plant.

I was hoping to miniaturize the nodes I already have, with comparable power saving features and possibly using less components.

I am not sure ... can be ethernet shield replaced with this ESP8266?

Basically the esp8266 provides the capability of a wifi shield.

Some differences are:
ESP8266 protocol is serial: Whatever you send to its serial line is interpreted as AT commands.
Since the normal serial line is also used to flash an Arduino, I think you should either use a MEGA (which has more than one serial port) or use soft serial to communicate with the ESP8266. One caveat is that soft serial does not work at the higher baud rates. I've had best result with the lowest baud rate (9600).

There is a shield schematic in ESP8266/Schematics/ESP8266Shield at master · Paulware/ESP8266 · GitHub that could be a replacement for an ethernet shield, but it would give you the additional wifi capability and would need AT commands to talk on the network.

No sensor is complete without a watchdog guarding against system lock-ups. I've had trouble using atmega328's internal hardware watchdog, so I will try to create one using a 555 timer. This will be similiar to the project: GitHub - mattbornski/Arduino-Watchdog-Circuit: The current Arduino library has bugs in the freelist implementation, which can lead to difficult to debug system hangs. For maximum reliability of my home automation projects, I built an external hardware watchdog., but I think I will use an npn transistor to ground the trigger line. Attached is a .jpg diagram of the idea.

555Watchdog.jpg

Hi all, I don't know if anyone else has come across the documentation for the AT commands, and their returned values, but I came across a document translated from Chinese to German, to English by
bafeigum on the hackaday blog. (thank you bafeigum!) Good information for newbies getting started, as well as great reference material.

ESP8266 WIFIATCOMMANDS_English.pdf (154 KB)

Well, you guy's are definitely way ahead of me for sure. Seems I spend more time searching for information than anything. I'm posting some of what I find in an effort to be helpful to those just picking up on this interesting module. I have been able to send commands through it to the UNO, described in a tutorial on the AllaboutEE site. That was the good news. The bad news is that the desired result, in this case clicking a button on an html page to turn on an LED has a tremendous lag. Also it seems that if a command is sent to quickly behind a previous one things get backlogged. It may take minutes to clear out. I'm not sure where all that is happening, but it definitely builds a case for programming the ESP for use on its own. In that regard, I came across a youtube video that helps understanding that concept. In case one hasn't seen it.

flagtrax

I'm not using this myself, but I'd recommend you take a look at the lua firmware, it can operate as a basic web server and you can still communicate to the Arduino via Serial , but you'd need to write your own command parser in lua

rogerClark:
I'm not using this myself, but I'd recommend you take a look at the lua firmware, it can operate as a basic web server and you can still communicate to the Arduino via Serial , but you'd need to write your own command parser in lua

The word I assume you're looking for is "NodeMCU" (link to firmware) and yeah I really recommend it as well. I wouldn't say it's required to spend a lot of learning time with lua though; in my case I just set it to act as a Wifi-to-serial bridge using some example programs I grabbed from the esp8266.com forums. I don't need an additional speck of lua code in my Arduino sketch after that initial setup.

The word I assume you're looking for is "NodeMCU" (link to firmware)

Yes :wink:

Hey guys.

I use ESP8266 module and Arduino UNO to control 40W light bulb via simple relay (5V input, 10A/250V output). In my first iteration of the project, I used LED diode instead of a light bulb. Everything was DC and everything worked fine! By the way, I give power supply to the ESP8266 module through 3.3V pin on the Arduino Uno board.

However, when I replace LED with a 40W light bulb supplied by AC, troubles appear! I eventually can ON/OFF light bulb just one or two times and everything just stop. It seems to me that the presence of the AC supplied wires introduces some noise that makes ESP8266 module confused and frozen.
I just wanted to hear from you about your experience with the ESP8266 module around AC wires. Did you encounter any trouble ? Is there anything I'm missing all the time ?

Thank you in advance for your time and effort.

Sincerely,
Bojan.

There's a new ESP8266 Arduino WiFi Shield available at www.8266.rocks. Lots of information including examples, schematics, instructions and tutorial videos are available here. http://www.8266.rocks/#!freeboarddweetexample/c3vb

Looks quite nice, I like the possibility of using it as either shield/standalone board, with the freedom to choose every pin you like. It's a pity only 2 types of modules can be used.

Unfortunately I won't be buying an 8266 soon, my wife won't even allow me to visit Ebay for more as 5 minutes a day, because of our bank account :frowning:

Anyway, I have been creating an Eagle Cadsoft library for modules 1 - 12 though plus 2 DW- modules.

Feel free to use it any way you like...

esp8266modules.zip (5.81 KB)

Hello,
Simplest way to send message from an Android app using ESP8266 to Arduino Mega? I would deeply appreciate help in terms of the Connection of the app and the ESP8266 ; and sending data, to light an led on pin 13 of Mega2560.
Thanks

What do you mean by

Arduino app

rogerClark:
What do you mean by

Arduino app

Sir,
Its ANDROID app.

OK.

Which "Android App" , there are so many of them :wink:

We made an app suggested by
http://allaboutee.com/2015/01/20/esp8266-android-application-for-arduino-pin-control/
But, issue is, it ain't working for us. So thought of sharing and getting some help form the forum.
i just wanna know Can I 'Send data, like a button press on an APP saying 'GO', which is read by the arduino Mega, via ESP8266, and send it to a particular PWM pin, say pin #2 on MEGA, to be read by other hardware connected to that particular PWM pin (#2)'
Thanks

i just wanna know Can I 'Send data, like a button press on an APP saying 'GO', which is read by the arduino Mega, via ESP8266, and send it to a particular PWM pin, say pin #2 on MEGA, to be read by other hardware connected to that particular PWM pin (#2)'

Yes. This is technically feasible

Sorry this is off -topic, but I have found the simplest way to communicate from Android to Mega or Arduino is using bluetooth and MIT App Inventor 2.

ESP8266 can work stand alone. Can switch on and off devices. I have seen it here. might as well help. http://thinkingparts.blogspot.com/2015/02/home-automation-lan-based-stand-alone.html

electricalhobbyist:
ESP8266 can work stand alone. Can switch on and off devices. I have seen it here. might as well help. http://thinkingparts.blogspot.com/2015/02/home-automation-lan-based-stand-alone.html

If you want it standalone, take a look also here:

It still looks more stable using ESP8266 Module as WIFI only module and run the Main Application on a separate MCU, but for small apps it's quite stable already :slight_smile: