Heltec WiFi Kit 32(V3)

Development Board

Code name: heltec_wifi_kit_32_V3

ESP32S3

Heltec WiFi Kit 32(V3) is a development board based on the ESP32S3 microcontroller using XTENSA architecture.

This board features a maximum CPU frequency of 240 MHz and 8MB flash memory.

About Heltec WiFi Kit 32(V3)

An ESP32-S3 board with integrated OLED display and LoRa capabilities, designed for wireless communication projects.

Technical Specifications

Complete technical specification details for Heltec WiFi Kit 32(V3)

Display

Type OLED

Size 0.96"

Connectivity

WiFi 802.11 b/g/n (2.4 GHz)

Bluetooth 5.0

BLE 5.0

Microcontroller

Model esp32s3

Clock Speed 240 MHz

Flash Size 8MB

SRAM 512KB

Architecture xtensa

✨ Features & Pins

Digital IO 40

Analog Input 16

PWM 22

Interrupts 16

Download Full Datasheet

Quick Setup

Copy-paste configs for Heltec WiFi Kit 32(V3) - auto‑generated from this board's exact hardware specs.

ESP32S3 240 MHz 8MB DIO Xtensa

In Arduino IDE 2 select Heltec Wifi Kit 32 V3 from the esp32 by Espressif package. In PlatformIO use board = esp32-s3-devkitm-1. ESP32S3 · 240 MHz · 8MB · DIO.

Tools menu settings

Board (select in Arduino IDE) Heltec Wifi Kit 32 V3

CPU Frequency 240 MHz

Flash Size 8MB

Flash Mode DIO

Upload Speed 921600

Architecture Xtensa

In Arduino IDE 2, open Boards Manager, search "esp32" by Espressif and install it. Then go to Tools → Board and select "Heltec Wifi Kit 32 V3" for the Heltec WiFi Kit 32(V3).

platformio.ini


[env:heltec_wifi_kit_32_V3]
platform  = espressif32
board     = esp32-s3-devkitm-1
framework = arduino

; Exact hardware config for Heltec WiFi Kit 32(V3)
board_build.mcu        = esp32s3
board_build.f_cpu      = 240000000L
board_build.flash_size = 8MB
board_build.flash_mode = dio
board_upload.flash_size = 8MB

The board value is a close generic match - check PlatformIO board registry for an exact fit.

esp32: block (YAML)


esp32:
  board: esp32-s3-devkitc-1
  framework:
    type: arduino   # or "esp-idf"

# Heltec WiFi Kit 32(V3) - 240 MHz ESP32S3
# Flash: 8MB | USB: N/A

Paste into your device's .yaml. See ESPHome ESP32 docs for full options.

esptool.py - flash command


esptool.py \
  --chip esp32s3 \
  --baud 921600 \
  write_flash \
    --flash_mode dio \
    --flash_size 8MB \
    0x0 bootloader.bin \
    0x8000    partitions.bin \
    0xe000    boot_app0.bin \
    0x10000   firmware.bin

Install: pip install esptool - replace firmware.bin with your binary - bootloader at 0x0

Heltec WiFi Kit 32(V3) Pinout Diagram

Complete pin reference for Heltec WiFi Kit 32(V3)

Useful Links

Datasheets and resources for Heltec WiFi Kit 32(V3)

Board Datasheet

Technical specifications

ESP32S3 Datasheet

Microcontroller reference

Pin Mappings

Complete pinout and GPIO mapping for Heltec WiFi Kit 32(V3)

Digital I/O Pins

Interrupt Pins

Analog Inputs

PWM Pins

Pin	Analog	Touch	PWM	Other
0				KEY_BUILTIN
1	A0	T1	PWM
2	A1	T2	PWM
3	A2	T3	PWM
4	A3	T4	PWM
5	A4	T5	PWM
6	A5	T6	PWM
7	A6	T7	PWM
8	A7	T8	PWM	SS
9	A8	T9	PWM	SCK
10	A9	T10	PWM	MOSI
11	A10	T11	PWM	MISO
12	A11	T12	PWM
13	A12	T13	PWM
14	A13	T14	PWM
15	A14		PWM
16	A15		PWM
17	A16		PWM	SDA_OLED
18	A17		PWM	SCL_OLED
19	A18		PWM
20	A19		PWM
21			PWM	SDA RST_OLED
22			PWM	SCL
35				LED_BUILTIN LED
36				Vext
43				TX
44				RX

Legend

A0 Analog input

T0 Touch sensor

PWM PWM capable

RX/TX Serial pins

LED Built-in LED

# Pin number

Default Tools & Configuration

Build and upload settings for Heltec WiFi Kit 32(V3)

Setting	Value
Bootloader tool	esptool_py
Uploader tool	esptool_py
Network uploader tool	esp_ota
Bootloader address	`0x0`
Flash mode	dio
Boot mode	qio
PSRAM type	qspi
Maximum upload size	3264 KB (3342336 bytes)
Maximum data size	320 KB (327680 bytes)