Esp and Arduino Programming

ESP8266+Arduino Tom Tobback www.cassiopeia.hk 2015 standard Arduino workshop 2014-2015

Materials

ESP8266+Arduino workshop 2015

Arduino and wifi Official Arduino wifi shield EUR 69 + VAT Sparkfun CC3000 shield USD 40 Adafruit CC3000 module USD 35


ESP8266 wifi module small powerfull cheap => IoT


Today’s setup


ESP8266 wifi module don’t need microcontroller 2 GPIO pins available on ESP-01

more on ESP-12


ESP8266 wifi module direct programming over USB/UART without 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-test esp8266-thingspeak-dht11-v3 esp8266-dht11-webserver WiFiWebServer-dht11-led


ESP8266 pinout Vcc = 3V3 GND UTXD = serial TX URXD = serial RX RST = reset CH_PD = pull up 4.6kOhm GPIO0 = input/output GPIO2 = 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. blink Connect ESP module Open IDE Serial Monitor Baud rate = 9600 Setting = “Both NL & CR”


ESP8266 test AT commands of standard firmware AT+RST AT+GMR

reset check firmware version

AT+CWMODE=3 AT+CWLAP AT+CWJAP=”ssid”,”password” AT+CIOBAUD? AT+CIOBAUD=9600

set mode to AP+STA list wifi networks connect to your wifi check baud rate set new baud rate

https://nurdspace.nl/ESP8266 ESP8266+Arduino workshop 2015

ESP8266 and software serial Arduino board has 1 hardware Serial on pin0 and pin1 but this is also used for uploading and for Serial Monitor Some 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 baud then can use software Serial for ESP8266 and hardware Serial for uploading/monitor as always new modules come set with default 9600 baud no update of firmware necessary software serial on e.g. pin10 and pin11 standard Arduino library


ESP8266 setup ESP8266 can act as: WEB SERVER serve web pages over existing wifi network ACCESS POINT create its own wifi network + web server WEB CLIENT communicate with web servers (e.g. thingspeak.com) over existing wifi network


ESP8266 web server AT+RST AT+CWMODE=1 AT+CWLAP AT+CWJAP=”ssid”,”pwd” AT+CIFSR AT+CIPMUX=1 AT+CIPSERVER=1,80

reset configure as node list access points connect to your wifi show ip address allow multiple connects start server on port 80

go to browser and type IP address check reply in serial monitor


ESP8266 web server go to browser and type IP address check reply in serial monitor +IPD, 0 [means connection id = 0] AT+CIPSEND=0,12 hello world [enter] AT+CIPCLOSE=0 see browser


ESP8266 access point AT+RST reset AT+CWMODE=2 configure as access point AT+CWSAP? get your AP details AT+CWSAP=”ssid”,”pwd”,1,3 define your wifi AP change to unique ssid connect to the AP with your phone AT+CIFSR show ip address AT+CIPMUX=1 allow multiple connects AT+CIPSERVER=1,80 start server on port 80 go to browser and type IP address check reply in serial monitor ESP8266+Arduino workshop 2015

ESP8266 web client AT+RST reset AT+CWMODE=1 configure as node AT+CWJAP=”ssid”,”pwd” connect to your wifi AT+CIPSTART=”TCP”,”184.106.153.149”,80 connect to TCP socket AT+CIPSEND= 4 wait for “>” GET [enter] check reply


ESP8266 web client ARDUINO SKETCH send commands over software serial espSerial.println("AT+RST"); construct String to send commands AT+CIPSTART=”TCP”,”184.106.153.149”,80 String cmd; cmd = "AT+CIPSTART=\"TCP\",\""; cmd += THINGSPEAK_IP; cmd += "\",80"; espSerial.println(cmd); ESP8266+Arduino workshop 2015

ESP8266 web client ARDUINO SKETCH construct HTTP request to be sent String cmd; cmd = "GET /update?key=xxxxxxxxxxxxxxxxxx&field1="; cmd += temp; cmd += "\r\n"; send the length of the command espSerial.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.com create a channel make public enter description field 1: temperature field 2: humidity save get API Write Key test in browser http://api.thingspeak.com/update? key=APIKEY&field1=23.66


DHT11 setup CONNECTIONS: ● 5V ● GND ● SIGNAL with pull-up resistor ARDUINO LIBRARY https://github.com/adafruit/DHT-sensor-library

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


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] ready AT+CWMODE=1 no change AT+CWJAP="tobback","xxxx" OK AT+CIPMUX=0 OK AT+CIPSTART="TCP","184.106.153.149",80 OK [or Error] Linked AT+CIPSEND=60 > GET /update?key=RD9SEODFNKIBZ11M&field1=22.00&field2=59.00 wrong syntax ERROR SEND OK +IPD,4:2107 OK


ESP8266-thingspeak-dht11-v3 sketch check espSerial feedback to know if commands are working send status over Serial for debugging DHT11 sensor sending data to THINGSPEAK.COM by ESP8266 sample 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 wifi cannot connect to wifi connected to wifi..>send thingspeak.com OK.. receive OK! 22.00degC 58.00% reset ESP8266..module ready..cannot connect to wifi connected 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 ThingTweet link 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)


ESP8266 with Arduino IDE Hardware connections: pull GPIO0 to GND (programming mode) connect URXD to TX connect URXD to RX power off/on in IDE: set Tools / Programmer / esptool set Tools / Board / generic ESP8266 set Tools / Port / xxx/usb0 upload BLINK with pin = 0 = GPIO0 release GPIO0 from GND connect GPIO0 to LED


ESP8266 with Arduino IDE use high level libraries: #include ... WiFiServer server(80); WiFi.begin(ssid, password); WiFiClient client = server.available(); ... String req = client.readStringUntil('\r'); ... client.print(s);


Thank you www.cassiopeia.hk Happy tinkering! standard Arduino workshop 2014-2015

Esp and Arduino Programming

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