N40 ESP32 Extension Board

The N40 is an expansion and breakout board for compatible ESP32 and ESP32-S3 development boards. It brings the GPIO, power, enable, and communication pins to clearly labeled 2.54 mm headers and screw terminals, making it easier to connect external modules, prototype circuits, and measure signals.

Key Features

• Breaks out the ESP32/ESP32-S3 GPIO and power pins for convenient access
• 2.54 mm pin headers for Dupont-wire connections
• 2.54 mm-pitch KF screw terminals for direct wire connections
• Dedicated 5 V and GND distribution headers
• GPIO status LEDs for visual signal indication
• TXS0108EPWR level-translation ICs with a specified data rate of up to 60 Mbps
• 7-12 V DC input through a 5.5 x 2.1 mm barrel connector
• Four 3 mm mounting holes

Compatible Core Boards

The extension board is designed for compatible ESP32 and ESP32-S3 boards with the required header arrangement. The product specification lists the following core-board options:

• ESP32-WROOM development board
• ESP32-S3-WROOM development board
• YD-ESP32-S3 N16R8 development board

Check the pinout before installation

ESP32 development boards are available with different dimensions and pin arrangements. Before applying power, verify that the core board matches the N40 socket spacing and that every 3.3 V, 5 V, GND, RST, TX, and RX pin is correctly aligned.

Specifications

Item	Specification
Product	N40 ESP32 Extension Board V1
DC input connector	5.5 x 2.1 mm barrel connector
Input power	7-12 V DC, 2 A
Recommended adapter	12 V DC, 2 A
Core-board female headers	44 pins, 25.4 mm row spacing
GPIO pin-header pitch	2.54 mm
Power-header pitch	2.54 mm
KF terminal pitch	2.54 mm
GPIO indicator color	Yellow-green
Level translation	TXS0108EPWR, up to 60 Mbps
Mounting holes	3 mm diameter
Mounting-hole spacing	80.20 x 73.20 mm
Board dimensions	87.00 x 80.00 x 12.00 mm
Operating temperature	-20 to 70 °C

Board Overview

The N40 provides three connection methods around the core-board sockets:

1. Signal headers - Use 2.54 mm Dupont leads to access GPIO, communication, reset, and power pins.
2. Power distribution headers - Use the dedicated 5 V and GND rows to power external sensors and modules.
3. KF screw terminals - Insert stripped wires and tighten the terminal screws for a secure connection.

The GPIO LEDs are connected to the corresponding core-board signals and provide a visual indication when the logic state changes.

Power Supply

Connect a regulated 7-12 V DC supply to the 5.5 x 2.1 mm barrel connector. A 12 V/2 A adapter is recommended.

Power connection

Confirm the adapter voltage, polarity, and core-board orientation before switching on the power. Do not connect an external supply directly to a GPIO pin.

Header Functions

Header	Function
J1, J3, J9	Break out the left-side GPIO, power, and enable pins of the installed core board
J2, J4, J10	Break out the right-side GPIO, power, and communication pins of the installed core board
J5, J6	Ground distribution; pins 1-22 are GND
J7, J8	5 V distribution; pins 1-22 provide 5 V for external devices
J0	7-12 V DC power input

J1, J3, and J9 Pin Definition

Pin	Name	Type	Function
1	3.3V	P	3.3 V output for an external sensor
2	3.3V	P	3.3 V output for an external sensor
3	RST	I	CHIP_PU; connected to the reset switch
4	GPIO4	I/O	GPIO4, TOUCH4, ADC1_CH3
5	GPIO5	I/O	GPIO5, TOUCH5, ADC1_CH4
6	GPIO6	I/O	GPIO6, TOUCH6, ADC1_CH5
7	GPIO7	I/O	GPIO7, TOUCH7, ADC1_CH6
8	GPIO15	I/O	GPIO15, U0RTS, ADC2_CH4, XTAL_32K_P
9	GPIO16	I/O	GPIO16, U0CTS, ADC2_CH5, XTAL_32K_N
10	GPIO17	I/O	GPIO17, U1TXD, ADC2_CH6
11	GPIO18	I/O	GPIO18, U1RXD, ADC2_CH7, CLK_OUT3
12	GPIO8	I/O	GPIO8, TOUCH8, ADC1_CH7, SUBSPICS1
13	GPIO3	I/O	GPIO3, TOUCH3, ADC1_CH2
14	GPIO46	I/O	GPIO46
15	GPIO9	I/O	GPIO9, TOUCH9, ADC1_CH8, SUBSPIHD, FSPIHD
16	GPIO10	I/O	GPIO10, TOUCH10, ADC1_CH9, FSPIIO4, SUBSPICS0, FSPICS0
17	GPIO11	I/O	GPIO11, TOUCH11, ADC2_CH0, FSPIIO5, SUBSPID, FSPID
18	GPIO12	I/O	GPIO12, TOUCH12, ADC2_CH1, FSPIIO6, SUBSPICLK, FSPICLK
19	GPIO13	I/O	GPIO13, TOUCH13, ADC2_CH2, FSPIIO7, SUBSPIQ, FSPIQ
20	GPIO14	I/O	GPIO14, TOUCH14, ADC2_CH3, FSPIDQS, SUBSPIWP, FSPIWP
21	5V	P	5 V power supply
22	GND	P	Ground

J2, J4, and J10 Pin Definition

Pin	Name	Type	Function
1	GND	P	Ground
2	TX	I/O	GPIO43, U0TXD, CLK_OUT1
3	RX	I/O	GPIO44, U0RXD, CLK_OUT2
4	GPIO1	I/O	GPIO1, TOUCH1, ADC1_CH0
5	GPIO2	I/O	GPIO2, TOUCH2, ADC1_CH1
6	GPIO42	I/O	GPIO42, MTMS
7	GPIO41	I/O	GPIO41, CLK_OUT1, MTDI
8	GPIO40	I/O	GPIO40, CLK_OUT2, MTDO
9	GPIO39	I/O	GPIO39, CLK_OUT3, SUBSPICS1, MTCK
10	GPIO38	I/O	GPIO38, FSPIWP, SUBSPIWP
11	GPIO37	I/O	GPIO37, FSPIQ, SUBSPIQ, SPIDQS
12	GPIO36	I/O	GPIO36, FSPICLK, SUBSPICLK, SPIIO7
13	GPIO35	I/O	GPIO35, FSPID, SUBSPID, SPIIO6
14	GPIO0	I/O	GPIO0
15	GPIO45	I/O	GPIO45
16	GPIO48	I/O	GPIO48, SPICLK_N
17	GPIO47	I/O	GPIO47, SPICLK_P
18	GPIO21	I/O	GPIO21
19	GPIO20	I/O	GPIO20, U1CTS, ADC2_CH9, CLK_OUT1, USB_D+
20	GPIO19	I/O	GPIO19, U1RTS, ADC2_CH8, CLK_OUT2, USB_D-
21	GND	P	Ground
22	GND	P	Ground

Type legend: P = power, I = input, I/O = input/output.

Dimensions

The extension board measures 87.00 x 80.00 x 12.00 mm. The mounting-hole center spacing is 80.20 x 73.20 mm, and the mounting holes accept 3 mm screws.

Package Contents

Item	Quantity	Notes
N40 ESP32 Extension Board V1	1	Included
12 V/2 A power adapter	1	Included according to the supplied product specification
ESP32-WROOM core board	1	Optional
ESP32-S3-WROOM core board	1	Optional
YD-ESP32-S3 N16R8 core board	1	Optional

Package contents may vary by product option. Check the selected product configuration before ordering.