Free Shipping on orders over US$49.99

ESP8266 Pinout | Pins and Their Functions of ESP8266 SoC


Espressif’s ESP8266 is a Wi-Fi SoC. It has all the bells and whistles for Wi-Fi Network connectivity as well as a very powerful processor. You can build applications using ESP8266 SoC alone but if you have a host MCU, then it can act as a slave as well. There are ESP8266 modules available in the market that you can use in your projects. But before starting, you have to be familiar with the pinout of the SoC as well as the module. So, in this tutorial, we will take a look at the ESP8266 Pinout.

First, we will see the pinout of the ESP8266 SoC. As ESP8266 Wi-Fi Chip is available in several modules, we will also see the pinout of some of those modules.

A Brief Note on ESP8266

The ESP8266 Wi-Fi Module changed the DIY and Hobbyist scene completely. It paved the way for small creators to build IoT and ‘Smart’ things. You can design a Smart Bulb or Smart Relay using ESP8266.

Since it has a powerful microprocessor, you can use it as a standalone device for the processor as well as for Wi-Fi connectivity. But the benefit of ESP8266 is that you can use another processor as the ‘main processing unit’ and use the ESP8266 just as a Wi-Fi chip.

ESP3266 Pinout

We will start understanding the pins of the ESP8266 with the main SoC itself. ESP8266 SoC is available in a 32-pin QFN Package (33 if you consider the center GND pad).

The following image shows the pin layout of the ESP8266 SoC.

ESP8266-Pinout-SoC-Image-1

From the above ESP8266 Pinout, you can see that it has only 1 pin (Pin 2 – LNA) for the RF Interface. This shows the level of integration ESP8266 has. Coming to the pins themselves, the following table shows the pin description of all the ESP8266 pins.

Pin Number Name Description
1 VDDA Analog Power Supply
2 LNA RF Antenna Interface
3 VDD3P3 Amplifier Power Supply
4 VDD3P3 Amplifier Power Supply
5 VDD_RTC NC
6 TOUT ADC Pin
7 CHIP_EN Chip Enable
8 XPD_DCDC Deep Sleep Wakeup
9 MTMS GPIO 14 / HSPI_CLK
10 MTDI GPIO 12 / HSPI_MISO
11 VDDPST Digital IO Power Supply
12 MTCK GPIO 13 / HSPI_MOSI / UART0_CTS
13 MTDO GPIO 15 / HSPI_CS / UART0_RTS
14 GPIO 2 GPIO 2 / UART TXs
15 GPIO 0 GPIO 0 / SPI_CS2
16 GPIO 4 GPIO 4
17 VDDPST Digital IO Power Supply
18 SDIO_DATA_2 SD_D2 / SPIHD / HSPIHD / GPIO 9
19 SDIO_DATA_3 SD_D3 / SPIWP / HSPIWP / GPIO 10
20 SDIO_CMD SD_CMD / SPI_CS0 / GPIO 11
21 SDIO_CLK SD_CLK / SPI_CLK / GPIO 6
22 SDIO_DATA_0 SD_D0 / SPI_MISO / GPIO 7
23 SDIO_DATA_1 SD_D1 / SPI_MOSI / GPIO 8
24 GPIO 5 GPIO 5
25 U0RXD UART RX / GPIO 3
26 U0TXD UART TX / GPIO 1 / SPI_CS1
27 XTAL_OUT Crystal Oscillator Output
28 XTAL_IN Crystal Oscillator Input
29 VDDD Analog Power Supply
30 VDDA Analog Power Supply
31 RES12K Serial Connection with 12 KΩ Resistor
32 EXT_RSTB External Reset Signal
33 GND Ground Pad

ESP-01 Pinout

The ESP-01 is one of the simplest ESP8266 modules available today. Ai-Thinker developed this module. It has the main SoC, crystal oscillator, flash memory, and a PCB antenna.

There are also 8 basic pins for programming as well as power. The following image shows the pins layout of ESP-01.

ESP8266 Arduino Image 2

Out of the 33 pins of ESP8266 SoC, the ESP-01 Module

Pin Name Pin Function
VCC Power Supply – 3.3V only
GND Ground
TX UART TX
RX UART RX
RST Reset
CH_PD Chip Enable
GPIO 0 GPIO 0
GPIO 2 GPIO 2

NodeMCU Pinout

While ESP-01 is the bare minimum ESP8266 Module, the NodeMCU is a popular compressive solution. It is a proper ESP8266 Development board with all the necessary connectors and components.

NodeMCU-Parts-on-Board

NodeMCU uses ESP-12E Module, again by Ai-Thinker. This module, like the ESP-01, has the SoC, Crystal Oscillator, and Wi-Fi Antenna. All the essential things for ESP8266 SoC. The main difference between ESP-01 and ESP-12E is the number of GPIO Pins.

Coming back to NodeMCU, it takes the ESP-12E as the base board and builds a complete system around it. The following image shows the Pinout of NodeMCU.

NodeMCU-Pinout-Image

It has 30 pins. You can see the pin description of all these 30 pins in the following table.

Pin Description Alternate Functions Default
ADC0 Analog Input  — ADC0
Reserved  —  —
Reserved  —  —
SDD3 SDIO Data 3 GPIO10 SDD3
SDD2 SDIO Data 2 GPIO9 SDD2
SDD1 SDIO Data 1 GPIO8 SDD1
SDDCMD SDIO CMD GPIO11 SDDCMD
SDD0 SDIO Data 0 GPIO7 SDD0
SDCLK SDIO CLK GPIO6 SDCLK
GND Ground  —  —
3.3V 3.3V Output  —  —
EN Chip Enable (Active HIGH)  —  —
RST Reset (Active LOW)  —  —
GND Ground  —  —
VIN 5V Input to 3.3V Regulator  —  —
3.3V 3.3V Output  —  —
GND Ground  —  —
TXD0 UART0 TXD GPIO1 TXD0
RXD0 USRT0 RXD GPIO3 RXD0
GPIO15 GPIO15 HSPI_CS / RTS0 GPIO15
GPIO13 GPIO13 HSPI_MOSI / CTS0 GPIO13
GPIO12 GPIO12 HSPI_MISO GPIO12
GPIO14 GPIO14 HSPI_SCK GPIO14
GND Ground  —  —
3.3V 3.3V Output  —  —
GPIO2 GPIO2 UART1 TXD GPIO2
Flash Flash GPIO0 Flash
GPIO4 GPIO4 Software SDA (I2C) GPIO4
GPIO5 GPIO5 Software SCL (I2C) GPIO5
GPIO16 GPIO16 Wake (deep sleep) GPIO16

ESP-12E Pinout

You can design your own NodeMCU if you have the ESP-12E Module. For that, you must be familiar with the Pinout of ESP-12E. The following image shows the pinout of the ESP-12E Module.

ESP-12E-Pinout

Here is the pin description of all the ESP-12E Pins.

Pin Function
RST Reset the Module
ADC0 ADC Pin with 10-bit resolution
EN Chip Enable Pin (active HIGH)
GPIO16 GPIO16 pin (wake pin from deep sleep mode)
GPIO14 GPIO14 pin (HSPI_CLK)
GPIO12 GPIO12 pin (HSPI_MISO)
GPIO13 GPIO13 pin (HSPI_MOSI)
VCC 3.3V Power Supply (max 3.6V)
SDCMD SDIO CMD (GPIO11)
SDD0 SDIO Data 0 (GPIO7)
SDD2 SDIO Data 2 (GPIO9)
SDD3 SDIO Data 3 (GPIO10)
SDD1 SDIO Data 1 (GPIO8)
SCCLK SDIO CLK (GPIO6)
GND Ground Pin
GPIO15 GPIO15 pin (HSPI_CS)
GPIO2 GPIO2 pin (TXD1)
Flash Flash Pin (GPIO0)
GPIO4 GPIO4 pin (SDA – software I2C)
GPIO5 GPIO5 pin (SCL – software I2C)
RXD0 UART0 RXD pin (GPIO3)
TXD0 UART0 TXD (GPIO1)

Conclusion

Even though ESP32 is a more powerful and capable SoC, the ESP8266 is still one of the popular choices for Wi-Fi Chips. Several DIY, as well as professional products, integrate ESP8266 in one form or the other. That is either directly as an SoC or as a Module.

Regardless, if you want to design projects using ESP8266, then you have to be familiar with the pins and pin functions. In this guide, we saw the ESP8266 Pinout. First, we saw the pinout of the main ESP8266 SoC.

Then we saw the pinouts of some popular modules such as ESP-01 and ESP-12E. We also looked at the pinout of NodeMCU.



Source link

We will be happy to hear your thoughts

Leave a reply

AmElectronics
Logo
Enable registration in settings - general
Compare items
  • Total (0)
Compare
0
Shopping cart