Program ESP8266-01 with USB to ESP8266 Adapter for Arduino

Objective: 

• Demonstrate how to program ESP8266 ESP-01 with its USB adapter

Equipment: 

• ESP8266 ESP-01
• ESP8266 USB adapter
• Shorting wire/assembly

ESP8266 kit can be purchased from Amazon.com

Learned Lesson:
1. GPIO0 has be grounded in order to program it.
2. CH_PD/EN need to connected to 3.3V in order to use ESP-01 after program is completed.
3. Software version must use 2.5.0.  Other version may not work.

Program Procedure:

• Open Arduino IDE
• In File --> References, enter "http://arduino.esp8266.com/stable/package_esp8266com_index.json" in "Additional Board Manager URLs" text box.

• In Tool --> Board: --> Board Manager type in 8266
• Install version 2.5.0.  Note: the correct version is very important.  

• In Tool --> Board: select "Generic ESP8266 Module"

• Modify "USB to ESP8266 Adapter for Arduino" module for shorting GND and GPIO0 temporary.

• Connect ESP8266-01 to above module and insert to computer's USB port

• Choose correct port.  From Tool --> Board: select correct port, in below example, it is COM 7.

• Open test file.  From File --> Examples --> ESP8266 --> Blink
• Upload the Blink program
• After upload is complete, the ESP8266-01's led should be blinking now.  

• If you want to program the same module again, please power cycle it (unplug and plug in from the USB port) before program it.

Trouble shooting:

1. Check your wiring
2. Check your ESP8266's driver version is 2.5.0
3. GND and GPIO0 has been shorted.
4. Power cycle it

Proclamation: 

• Above steps are learned from Electronic Guru's video, https://www.youtube.com/watch?v=P8Z-ZHwNeNI

Bonus:
Program ESP8266 ESP-01 with FT232RL FTDI USB to TTL Serial Converter Adapter

Proclamation: 
  Below procedure is inspired from https://iot-playground.com/blog/2-uncategorised/67-arduino-esp8266-ide

Procedure:

1. Plug in above USB adapter

2. Check if your computer can find its COM port if yes, skip to step 4

3. Install driver manually from https://www.ftdichip.com/Drivers/VCP.htm or just run the EXE file from https://www.ftdichip.com/Drivers/CDM/CDM21228_Setup.zip.

4. Connect your adapter as shown in below diagram.

5. Setup your Arduino IDE for ESP8266 as shown in previous procedure.

6. Upload a test program, it should work now.

7. Before your try to upload another program, you need to reset it first (unplug and plug its power pin).

 https://iot-playground.com/blog/2-uncategorised/67-arduino-esp8266-ide

Other Code Example:

  Below code is using ESP8266 ESP-01 with Adafruit's MQTT.  LED on ESP-01 can be remotely turned on or off, and ESP-01 push a new value to io.adafruit.  It is just for your reference only, and we will not discuss it in this project.

#include <ESP8266WiFi.h>

#include "Adafruit_MQTT.h"

#include "Adafruit_MQTT_Client.h"

/************************* WiFi Access Point *********************************/

#define WLAN_SSID       "*******"

#define WLAN_PASS       "*******"

/************************* Adafruit.io Setup *********************************/

#define AIO_SERVER      "io.adafruit.com"

#define AIO_SERVERPORT  1883                   // use 8883 for SSL

#define AIO_USERNAME    "*******"

#define AIO_KEY         "*******"

WiFiClient client;

Adafruit_MQTT_Client mqtt(&client, AIO_SERVER, AIO_SERVERPORT, AIO_USERNAME, AIO_KEY);

Adafruit_MQTT_Publish   count =  Adafruit_MQTT_Publish(&mqtt, AIO_USERNAME "/feeds/count");

Adafruit_MQTT_Subscribe onoffbutton  = Adafruit_MQTT_Subscribe(&mqtt, AIO_USERNAME "/feeds/onoff");

void MQTT_connect();

void setup() {

  Serial.begin(115200); delay(10);

  // Connect to WiFi access point.

  Serial.println(); Serial.println();

  Serial.print("Connecting to ");

  Serial.println(WLAN_SSID);

  WiFi.begin(WLAN_SSID, WLAN_PASS);

  while (WiFi.status() != WL_CONNECTED) {

    delay(500);

    Serial.print(".");

  }

  Serial.println();

  pinMode(1, OUTPUT);

  

  Serial.println("WiFi connected");

  Serial.println("IP address: "); Serial.println(WiFi.localIP());

  // Setup MQTT subscription for onoff feed.

  mqtt.subscribe(&onoffbutton);

}

int count_value=0;

void loop() {

  MQTT_connect();

  Adafruit_MQTT_Subscribe *subscription;

  while ((subscription = mqtt.readSubscription(5000))) {

    if (subscription == &onoffbutton) {

      Serial.print(F("Got: "));

      Serial.println((char *)onoffbutton.lastread);

      if(onoffbutton.lastread[1]==78){digitalWrite(1,HIGH);Serial.print("Light on");}

      if(onoffbutton.lastread[1]==70){digitalWrite(1,LOW);Serial.print("Light off");}

    }

  }

  

  count_value++ ;

  

  // Now we can publish stuff!

  Serial.print(F("\nSending pressure val ")); Serial.print(count_value);Serial.print("...");

  if (! count.publish(count_value)) {Serial.println(F("Failed"));} else { Serial.println(F("OK!"));  }

  delay(1000);

}

// Function to connect and reconnect as necessary to the MQTT server.

// Should be called in the loop function and it will take care if connecting.

void MQTT_connect() {

  int8_t ret;

  // Stop if already connected.

  if (mqtt.connected()) {

    return;

  }

  Serial.print("Connecting to MQTT... ");

  uint8_t retries = 3;

  while ((ret = mqtt.connect()) != 0) { // connect will return 0 for connected

       Serial.println(mqtt.connectErrorString(ret));

       Serial.println("Retrying MQTT connection in 5 seconds...");

       mqtt.disconnect();

       delay(5000);  // wait 5 seconds

       retries--;

       if (retries == 0) {

         // basically die and wait for WDT to reset me

         while (1);

       }

  }

  Serial.println("MQTT Connected!");

}