• Esp8266 Softwareserial
• Esp8266 Softserial
• Esp8266 Web Server Examples

GOAL

Fi based board that uses the Arduino layout with a operating voltage of 3. Software Serial Esp 8266 Projects Ota' title='Software Serial Esp 8266 Creative Advertising Pdf Books: Software Free Download. Veterans Burial Program Fair Oaks Ca. Download Song Maahi Ve From Movie Kaante. Introduction: Programming the ESP8266-12E Using Arduino Software/IDE. By jainrk Follow More by the author: The ESP8266 is like an Arduino with a builtin WiFi, the MCU and WiFi circuitry are in the same chip. Consider Arduino + WiFi Shield = ESP8266. In this instructable I will provide a step by step guide to procure and programming an ESP8266-12E WIFI Development Board. You will also learn how. Some boards have all kinds of features on-board to help developing ESP 8266 hardware and software: for example, a USB to Serial converter for programming, a 3.3V regulator for power, on-board LEDs for debugging, a voltage divider to scale the analog input.

From Arduino UNO, send AT commands to ESP8266 via a SoftwareSerial port and receive results.

CURRENT STATUS

I either send AT commands and get nothing back (wiring scheme 1) or I send AT commands and get garbage back (wiring scheme 2).

Using the Arduino as a pass through (as explained in the tutorial listed in the resources section), I can send AT commands. I have found that I can communicate with the ESP8266 at 115200 baud.

This is the results of running AT+GMR:

WIRING SCHEME 1

!! I have the green wire attached to pin 3 on the Arduino Uno and the yellow wire attached to pin 2; not 1 and 0 as the picture suggests !!

WIRING SCHEME 2

Same wiring as above, but I have RX and TX reversed. The green wire is attached to pin 2 and the yellow wire is attached to pin 3.

CODE

This is running on Arduino Uno

RESULTS FROM RUNNING SKETCH

Wiring Scheme 1

Wiring Scheme 2

I have tested the ESP8266 via the instructions listed in the tutorial in the Resources I've Used section below. The ESP8266 works just fine when sending it instructions via the Serial Prompt.

RESOURCES I'VE USEDhttp://rancidbacon.com/files/kiwicon8/ESP8266_WiFi_Module_Quick_Start_Guide_v_1.0.4.pdf

QUESTION

Does anyone know if what I am trying to do is possible? And if it is, what am I doing wrong?

6 Answers

Does anyone know if what I am trying to do is possible?

Absolutely possible :)

And if it is, what am I doing wrong?

SoftwareSerial isn't capable of 115200 baud rate (despite 'allowing' this as a setting). Some reports suggest as high as 57600 is workable, though in my experience 9600 is best for reliability. How to change the baud rate on the ESP8266 will depend on the firmware version. I've had success with AT+IPR=9600. You only need to run this command once (it's a persistent setting). I'd suggest, based on your description, that this is the most likely culprit that's causing the 'garbage' output you describe.

A couple of other notes:

• The ESP8266 runs on 3v3, not 5v, so you shouldn't have it directly connected to the digital pins—you need to run through a logic level converter. Running 5v can fry your ESP8266.
• The Arduino's 3v3 output has insufficient current to support the ESP8266 reliably (50mA Arduino vs up to 300mA for the ESP8266 by some accounts)—try running the ESP8266 off a separate supply. It probably won't affect simple commands like AT but when you try to connect to a network etc. it may cause unexpected device resets.
• As noted by others, you need to send rn — so make sure your Serial window is set to send both (this is a drop-down in the serial window)

Well you may try this:

Start by uploading blink sketch to your Arduino then connect it to your ESP8266 like this: TX-TX and RX-RX.

Now open Serial Monitor and send AT command and see if it responds. If so then you can control it using your Arduino by wiring it back to TX-RX and RX-TX.

PS: Don't forget to set the line ending in the Serial Monitor to Newline or Carriage Return.

Use this code to connect to ESP8266:

Since the Hardware Serial interface will be busy when connected to Computer, then you have to use another Serial interface to communicate with your ESP8266. In this case, Software Serial comes handy.

Does anyone know if what I am trying to do is possible?It is possible, i've done it with 2 arduinos where one was simulating ESP8266 (waiting for ebay order).

And if it is, what am I doing wrong?

What you are doing is wrong on most levels, but i think you got most sorted out.

An idea is to implement this little fella: Logic level shifter it will save you many troubles later.

On your 'WIRING SCHEME 1' you are using the arduino's Hardware serial port to talk directly to the device as if it was connected through a TTL cable or FTDI cable.

This means that the arduino device would in theory read from the hardware when talking too the ESP8266, if you have another arduino or a TTL cable, try and connect it to gate 2 and 3 on the 'main' arduino and you should get a similar result as for your example result 2. Since you would that way proxy through the arduino. If not that would be a place to start debugging.

Beside that i could only recommend you in investing in either a TTL 3,3v or a logic level converter. When i got my cable everything worked out of the box.

I had lot of problems as well. In my case problems are almost solved by switching from SoftwareSerial to AltSoftSerial. It seemed that on the Uno the standard software serial library was not working for me. After switching I started to get results back for the first time. (I also used level shifting and external power supply for 3.3V)

And by almost solved I mean - I still get, from time to time, gibberish on the terminal. So even AltSoftSerial isn't a perfect solution. I was using the ESP-07 with a 115200 bps data rate.

We found that many of the problems with the ESP - Arduino Uno serial software integration had to do with incompatible baudrate. We created this short tutorial (including a Github library) which you are welcome to test and see if it solves these issues. http://www.instructables.com/id/Simple-ESP8266-Arduino-Uno-Software-Serial-Integra/

Here are a few tips when using ESP8266 Module.

1. Don't use software serial as it's unreliable especially at higher baud rates.

2. Always connect ESP module to computer and test all AT commands before interacing with Arduino to ensure that you are working in right direction

3. Make a power adaptor board to make ESP module compatible with Arduino 5v supply

Also check out this link for more details

Not the answer you're looking for? Browse other questions tagged arduino-unoesp8266softwareserial or ask your own question.

Implementation of the Arduino software serial library for the ESP8266

This fork implements interrupt service routine best practice.In the receive interrupt, instead of blocking for whole bytesat a time - voiding any near-realtime behavior of the CPU - phasedetection and byte assembly is done in the main code.

Except at high bitrates, depending on other ongoing activity,interrupts in particular, this software serial adaptersupports full duplex receive and send. At high bitrates (115200bps)send bit timing can be improved at the expense of blocking concurrentfull duplex receives, with the SoftwareSerial::enableIntTx(false) function call.

Same functionality is given as the corresponding AVR library butseveral instances can be active at the same time. Speed up to 115200 baudis supported. The constructor also has an optional input buffer sizearguments.

Please note that due to the fact that the ESP always have other activitiesongoing, there will be some inexactness in interrupt timings. This maylead to inevitable, but few, bit errors when having heavy data trafficat high baud rates.

Resource optimization

Esp8266 Softwareserial

The memory footprint can be optimized to just fit the amount of expectedincoming asynchronous data.For this, the SoftwareSerial constructor provides two arguments. First, theoctet buffer size for assembled received octets can be set. Read calls aresatisfied from this buffer, freeing it in return.Second, the signal edge detection buffer of 32bit fields can be resized.One octet may require up to to 10 fields, but fewer may be needed,depending on the bit pattern. Any read or write calls check this bufferto assemble received octets, thus promoting completed octets to the octetbuffer, freeing fields in the edge detection buffer.

Look at the swsertest.ino example. There, on reset, ASCII characters ' ' to 'z'are send. This happens not as a block write, but in single write calls percharacter. As the example uses a local loopback wire, every outgoing bit isimmediately received back. Therefore, any single write call causes up to10 fields - depending on the exact bit pattern - to be occupied in the signaledge detection buffer. In turn, as explained before, each single write callalso causes received bit assembly to be performed, promoting these bits fromthe signal edge detection buffer to the octet buffer as soon as possible.Explaining by way of contrast, if during a a single write call, perhaps becauseof using block writing, more than a single octet is received, there will be aneed for more than 10 fields in the signal edge detection buffer.The necessary size of the octet buffer only depends on the amount of incomingdata until the next read call.

For the swsertest.ino example, this results in the following optimizedconstructor arguments to spend only the minimum RAM on buffers required:

The octet buffer size (bufSize) is 93 (91 characters net plus two tolerance).The signal edge detection buffer (isrBufSize) is 10, as each octet has 10bits on the wire, which are immediately received during the write, and eachwrite call causes the signal edge detection to promote the previously sent andreceived bits to the octet buffer.

In a more generalized scenario, calculate the bits (use message size in octetstimes 10) that may be asynchronously received to determine the value forisrBufSize in the constructor. Also use the number of received octetsthat must be buffered for reading as the value of bufSize.The more frequently your code calls write or read functions, the greater thechances are that you can reduce the isrBufSize footprint without losing data,and each time you call read to fetch from the octet buffer, you reduce theneed for space there.

Esp8266 Softserial

The size of the tables needed for interrupt dispatch can be adapted to theactual maximum number of SoftwareSerial instances in a sketch.To reduce the memory footprint of these tables, define SOFTWARESERIAL_MAX_INSTSto the total number of SoftwareSerial objects your sketch uses.

Updating EspSoftwareSerial in the esp8266com/esp8266 Arduino build environment

The EspSoftwareSerial is used as a Git submodule in the esp8266 source tree,specifically in .../esp8266/libraries/SoftwareSerial when using a Githubrepository clone in your Arduino sketchbook hardware directory.This supersedes any version of EspSoftwareSerial installed for instance viathe Arduino library manager.

The responsible maintainer of the esp8266 repository has kindly shared thefollowing command line instructions:

To update esp8266/arduino SoftwareSerial submodule to lastest master:

Esp8266 Web Server Examples

(optional, clean it:)$ rm -rf libraries/SoftwareSerial$ git submodule update --init(now update it:)$ cd libraries/SoftwareSerial$ git checkout master$ git pull