NodeMCU esp8266 pinout. Using Arduino with simple LED Blink

Introduction

Hello, so you are here to learn automation and IoT. Automation and IoT are trending field these days, everyone either try to get gadgets for it or try to make their gadget. There are different modules and processors available for it like Arduino, Raspberry pi, etc. But the simplest and most popular module for IoT is NodeMCU. Espressif systems developed it. There are many variations of it, and the main difference is the number of available pins. Just as an example, ESP01 has eight pins available while ESP32S has 38 pins. Programming techniques are the same for almost all NodeMCU/ESP8266 modules. In this NodeMCU esp8266 pinout blog, I am using 30 Pin NodeMCU Amica which is WiFi module-based development board. It is an introductory level blog, a practical introduction to this NodeMCU microcontroller.  NodeMCU has a built-in microcontroller and WiFi, so you can use it to perform different tasks and use WiFi to store the result on cloud or real-time monitoring. One of the key features is that it can be programmed using Arduino IDE. This program will use a simple blink-led program to verify our hardware and learning.

Learning Goals

1. Understand essential pins of NodeMCU
2. How to configure Arduino environment to program NodeMCU
3. Uploading and running blink code

Hardware Requirements to Program NodeMCU ESP8266

1. NodeMCU
2. Breadboard
3. Arduino
4. Led

A Brief  Introduction to NodeMCU Hardware Structure.

A 30 pin NodeMCU ESP8266  is shown in figure below.

 

If you look at its pins, it seems to be quite similar to our Arduino. 

WiFi Chip: Its main component is the ESP8266 WiFi Chip. Using this WiFi chip, we can connect to the Internet. 

Digital Pins: In our selected NodeMCU ESP8266 Module, there are a total of 9 digital pins D0 to D9. These pins are in two groups D0 to D4 and D5 to D8. Digital pin means that they can be either low or high. So we can use these pins to control such devices, which can be either ON or OFF like Relay, LCD, and IR sensors, etc.

TX and RX pins: These pins are used for serial commination with different devices.

Power Supply Pins (3.3V & Ground):  NodeMCU uses 3.3V for its operation. There are three sets of these pins on NodeMCU. 

Analog Pin: There is only one Analog pin for this module, labeled as A0. 

External Peripheral Pins: Pin S0 to S3 are used to connect external peripherals like External RAM, micro process, etc. We cannot use them as analog or digital pins to connect a device.

Vin: This is an external power supply for NodeMCU. You can apply 7V-12V at this pin. 

Programming Port: You can also use the programming port to program NodeMCU. You can also power up NodeMCU through this pin.

Reserved Pins:  These are reserved pins. We will not use them.

Control Pins: These are reset and enable pins labeled as RST & EN. There are also Reset and Enable buttons for the same purpose.

Arduino Configuration Steps

Download and install the latest version of Arduino software.

Open Arduino IDE 

File > preference

In Additional Boards Managers URL, paste below line. http://arduino.esp8266.com/stable/package_esp8266com_index.json

If there is already some board, then separate it with a comma.

Next, go to Tools > Board >Board Managers

and search for esp8266 and install it as shown in the figure below. It will install all boards related to this module

Tools > Boards > ESP8266 Boards > NodeMCU 1.0 (ESP-12E Module)

Now, you can see that NodeMCU Board is selected.

Now, we are ready to program NodeMCU esp8266 pinout with Arduino IDE.

Connect NodeMCU with Laptop/PC.

 tools > Port. Select appropriate port.

Writing Blinking Program

Write below Code or copy it in Arduino IDE.

 

#define led  D5

void setup() {

pinMode(led,OUTPUT);

}

void loop() {

digitalWrite(led,HIGH);

delay (1000);

digitalWrite(led,LOW);

delay  (1000);

}

 Code Explanation:
We define the D5 pin of NodeMCU for external led at the first line.
The second line is void setup. We write that command here, which runs once in the whole program.
In the third line, led is defined as OUTPUT.
Line 5 is a void loop.
In Line 6, we set D5 pin HIGH. It means turning led ON.
Following the line, we give a delay of 1 second.
At line 8, we turn led OFF by setting D5 Low.
Then a delay of 1 Second.

Output

Connect the anode of led with D5 and cathode with the ground of NodeMCU.
Compile and run this code. If there is no error, the led will start blinking.
You can remove the programming cable and give supply from any other source or mobile chargers. Led will continue blinking as long as power is applied.

Conclusion

In this NodeMCU esp8266 pinout blog, we have seen how the NodeMCU and Arduino Interface works, how to upload and run a simple program WiFi Module. Understand different pins of NodeMCU and their utilization. As I mentioned before that this is a basic level blog, and this knowledge will be further refined through the more advanced program in near future.

If you like, kindly comment.

Regards