Cassiopeia Ltd - ESP8266+Arduino workshop

standard Arduino workshop 2014-2015

ESP8266+Arduino

Tom Tobbackwww.cassiopeia.hk2015

ESP8266+Arduino workshop 2015

Materials


Arduino and wifiOfficial Arduino wifi shieldEUR 69 + VAT

Sparkfun CC3000 shieldUSD 40

Adafruit CC3000 moduleUSD 35


ESP8266 wifi module

small

powerfull

cheap

=> IoT


Today’s setup


ESP8266 wifi module

don’t need microcontroller2 GPIO pins availableon ESP-01

more on ESP-12


ESP8266 wifi moduledirect programming over USB/UARTwithout using Arduino board as micro-controller

1. esptool.py

2. NodeMCU - Lua

3. Arduino IDE!

https://github.com/esp8266/Arduino


Today’s setup


Downloads

http://www.dimsumlabs.com/

click on ESP8266 event

● DHT library zipped● zip file with:

esp8266-thingspeak-dht11-testesp8266-thingspeak-dht11-v3esp8266-dht11-webserverWiFiWebServer-dht11-led




ESP8266 pinout

Vcc = 3V3 GNDUTXD = serial TXURXD = serial RXRST = reset

CH_PD = pull up 4.6kOhmGPIO0 = input/outputGPIO2 = input/output


ESP8266 test

Communicate with ESP8266 using Serial converter on our Arduino board

● Vcc = 3V3 ● GND● URXD = serial RX = pin0● UTXD = serial TX = pin1

note: pins seem 5V tolerant


ESP8266 test

Communicate with ESP8266 using Serial converter on our Arduino board (RX, TX)

Upload any sketch not using Serial e.g. blinkConnect ESP moduleOpen IDE Serial MonitorBaud rate = 9600Setting = “Both NL & CR”


ESP8266 test

AT commands of standard firmware

AT+RST resetAT+GMR check firmware version

AT+CWMODE=3 set mode to AP+STAAT+CWLAP list wifi networksAT+CWJAP=”ssid”,”password” connect to your wifiAT+CIOBAUD? check baud rateAT+CIOBAUD=9600 set new baud rate

https://nurdspace.nl/ESP8266


ESP8266 and software serialArduino board has 1 hardware Serial on pin0 and pin1but this is also used for uploading and for Serial MonitorSome earlier modules had baud rate 115200 and their firmware did not allow to change it. would only work with hardware Serial, so Serial Monitor over software Serial + USB converter


ESP8266 and software serial

Better solution:use updated firmware to allow 9600 baudthen can use software Serial for ESP8266and hardware Serial for uploading/monitor as always

new modules come set with default 9600 baudno update of firmware necessary

software serial on e.g. pin10 and pin11standard Arduino library


ESP8266 setup

ESP8266 can act as:

WEB SERVERserve web pages over existing wifi network

ACCESS POINTcreate its own wifi network + web server

WEB CLIENTcommunicate with web servers (e.g. thingspeak.com)over existing wifi network


ESP8266 web server

AT+RST resetAT+CWMODE=1 configure as nodeAT+CWLAP list access pointsAT+CWJAP=”ssid”,”pwd” connect to your wifiAT+CIFSR show ip addressAT+CIPMUX=1 allow multiple connectsAT+CIPSERVER=1,80 start server on port 80

go to browser and type IP addresscheck reply in serial monitor


ESP8266 web server

go to browser and type IP addresscheck reply in serial monitor

+IPD, 0 [means connection id = 0]

AT+CIPSEND=0,12hello world [enter]AT+CIPCLOSE=0

see browser


ESP8266 access point

AT+RST resetAT+CWMODE=2 configure as access pointAT+CWSAP? get your AP detailsAT+CWSAP=”ssid”,”pwd”,1,3

define your wifi APchange to unique ssid

connect to the AP with your phoneAT+CIFSR show ip addressAT+CIPMUX=1 allow multiple connectsAT+CIPSERVER=1,80 start server on port 80go to browser and type IP addresscheck reply in serial monitor


ESP8266 web client

AT+RST resetAT+CWMODE=1 configure as nodeAT+CWJAP=”ssid”,”pwd” connect to your wifiAT+CIPSTART=”TCP”,”184.106.153.149”,80

connect to TCP socket

AT+CIPSEND= 4wait for “>”GET [enter]check reply


ESP8266 web client

ARDUINO SKETCH send commands over software serial

espSerial.println("AT+RST");

construct String to send commandsAT+CIPSTART=”TCP”,”184.106.153.149”,80String cmd; cmd = "AT+CIPSTART=\"TCP\",\"";cmd += THINGSPEAK_IP;cmd += "\",80";espSerial.println(cmd);


ESP8266 web clientARDUINO SKETCH

construct HTTP request to be sentString cmd;cmd = "GET /update?key=xxxxxxxxxxxxxxxxxx&field1=";cmd += temp;cmd += "\r\n";send the length of the commandespSerial.print("AT+CIPSEND=");espSerial.println(cmd.length());

wait for “>” with espSerial.find(">")espSerial.println(cmd);decode the reply with espSerial.find("SEND OK")


thingspeak.com

create an account on thingspeak.comcreate a channelmake publicenter description

field 1: temperaturefield 2: humidity

saveget API Write Key

test in browser http://api.thingspeak.com/update?key=APIKEY&field1=23.66


CONNECTIONS:● 5V● GND● SIGNAL with pull-up resistor

ARDUINO LIBRARYhttps://github.com/adafruit/DHT-sensor-library

ARDUINO SKETCH#include <DHT.h>DHT dht(3, DHT11);pinMode(3, INPUT); // DHT11dht.begin();float h = dht.readHumidity();float t = dht.readTemperature();

DHT11 setup


ESP8266-thingspeak-dht11-test sketch

22.00degC 59.00% reset ESP8266..ó#âáT%ÐÇCÁaæ l!ÈÅèchKäFgÚ¡P¥øäæ |cø[Vendor:www.ai-thinker.com Version:0.9.2.4]readyAT+CWMODE=1no changeAT+CWJAP="tobback","xxxx"OKAT+CIPMUX=0OKAT+CIPSTART="TCP","184.106.153.149",80OK [or Error]LinkedAT+CIPSEND=60> GET /update?key=RD9SEODFNKIBZ11M&field1=22.00&field2=59.00wrong syntaxERRORSEND OK+IPD,4:2107OK


ESP8266-thingspeak-dht11-v3 sketch

check espSerial feedback to know if commands are workingsend status over Serial for debugging

DHT11 sensor sending data to THINGSPEAK.COM by ESP8266sample interval (s): 5

22.00degC 57.00% reset ESP8266..module ready..connected to wifi..>send thingspeak.com OK.. receive OK!22.00degC 59.00% reset ESP8266..module ready..cannot connect to wificannot connect to wificonnected to wifi..>send thingspeak.com OK.. receive OK!22.00degC 58.00% reset ESP8266..module ready..cannot connect to wificonnected to wifi..>send thingspeak.com OK.. receive OK!


ESP8266-twitter-dht11-v3 sketch

twitter via thingspeak.com: tweet from your Arduino

in Thingspeak:add app ThingTweetlink to twitter account

in sketch:“GET /apps/thingtweet/1/statuses/update/api_key=KEY&status=”;


ESP8266 with Arduino IDE

Customised IDE using esptool to upload/flash Arduino-style sketches https://github.com/esp8266/Arduino Needs Serial-USB converter (UART)

https://github.com/esp8266/Arduino



Hardware connections:pull GPIO0 to GND (programming mode)connect URXD to TXconnect URXD to RXpower off/on

in IDE:set Tools / Programmer / esptoolset Tools / Board / generic ESP8266set Tools / Port / xxx/usb0

upload BLINK with pin = 0 = GPIO0release GPIO0 from GNDconnect GPIO0 to LED



use high level libraries:

#include <ESP8266WiFi.h>...WiFiServer server(80);WiFi.begin(ssid, password);WiFiClient client = server.available();...String req = client.readStringUntil('\r');...client.print(s);

standard Arduino workshop 2014-2015

Thank you

www.cassiopeia.hk

Happy tinkering!

http://www.cassiopeia.hk

http://www.cassiopeia.hk

Technology

Cassiopeia Ltd - ESP8266+Arduino workshop