WEMOS LOLIN32 Lite Development Board

Code name: LOLIN32_LITE

WEMOS LOLIN32 Lite development board is based on esp32 microcontroller and uses xtensa architecture. This board has a maximum CPU frequency of 240 MHz and a flash size of 4MB.

⚡ Tech Specs 📌 Pinout 🔗 Useful Links 🗺️ Mappings 🛠️ Tools

About WEMOS LOLIN32 Lite

The WEMOS LOLIN32 Lite squeezes Espressif’s dual-core ESP32-WROOM-32 module into a slim 57 × 25 mm board that still accepts the classic LOLIN/D1-mini shield ecosystem. It ships with 4 MB of flash, runs up to 240 MHz, and offers both Wi-Fi 802.11 b/g/n and Bluetooth 4.2 (BR/EDR + BLE) for rock-solid wireless connectivity. 📡

A low-cost CH340C USB-to-UART bridge handles programming and serial debugging via the Micro-USB port and supports auto-reset/boot so you can flash sketches without pushing buttons. :contentReference

Onboard power management is Li-Po ready: a TP4054 charger (≈ 500 mA) and a PH-2 battery connector (BAT) let you run projects untethered while the board trickle-charges whenever USB is present. ⚡️

Convenience extras include a RESET push-button, a BOOT (IO0) button for manual download-mode entry, and a bright blue on-board LED on GPIO 5 for quick status indication.

With 22 GPIOs (all PWM-capable), 12-bit ADCs, dual 8-bit DACs, 10 capacitive-touch pads, plus I²C, SPI, UART, SD-card, and RTC IO support, the LOLIN32 Lite punches far above its weight for battery-powered IoT nodes, wearables, or compact sensor gateways. ⚙️

Where to Buy

Starting from

$5 per unit

Amazon.com Ships worldwide

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Amazon.de Ships to EU

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AliExpress Best value

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Prices are subject to change. We earn from qualifying purchases as an Amazon Associate.

Technical Specifications

🔌 USB

Type Micro-USB

Serial Chip CH340

🛰️ Connectivity

WiFi 802.11 b/g/n (2.4 GHz)

Bluetooth 4.2

BLE 4.2

🧠 Microcontroller

Model esp32

Clock Speed 240 MHz

Flash Size 4MB

Architecture xtensa

✨ Features

40 digital IO pins
16 external interrupt pins
16 analog input pins
18 PWM pins

View Full Datasheet

WEMOS LOLIN32 Lite Dimensions

Width 25.4 mm

Length 58 mm

Pin Gap 2.54 mm

WEMOS LOLIN32 Lite Pinout

The LOLIN32 Lite pinout fans out 26 ESP32 GPIOs on two rows, mirroring the original D1-mini shield headers for easy stacking.

Power rails: use USB 5V (or VIN) as input, the regulated 3V3 pin for logic-level peripherals, and the dedicated BAT pin for a single-cell Li-Po. Multiple GND pads provide solid returns.

Serial: U0_TX (GPIO1) and U0_RX (GPIO3) connect to the CH340C for programming/logging. Need more ports? U2_TX (GPIO17) and U2_RX (GPIO16) are free for GPS or RS-485 transceivers.

I²C defaults to SDA (GPIO21) and SCL (GPIO22), broken out on the shield D2/D1 lines—but any spare GPIO can be reassigned.

SPI: the primary VSPI bus (best for OLEDs, SD adapters, radios) maps to MOSI (GPIO23), MISO (GPIO19), SCK (GPIO18), and CS (GPIO5). A secondary HSPI bus lives on GPIO12-15 when you need a second device.

Analog & touch: Eight ADC1 channels (GPIO32-GPIO39) work even with Wi-Fi on. Extra ADC2 pads (GPIO0, 2, 4, 12-15, 25-27) share RF hardware. Dual 8-bit DAC outputs are on GPIO25 and GPIO26. Ten pads double as capacitive-touch inputs—great for touch keys or wake-up gestures.

Every GPIO can generate high-resolution PWM (up to ≈40 kHz). Remember the boot-strap pins—GPIO0, GPIO2, and GPIO15—must sit HIGH (with proper pull-ups) on reset for a normal boot.

With battery charging, robust power rails, and a shield-friendly layout, the LOLIN32 Lite pinout makes it effortless to go from breadboard prototype to compact, battery-powered product.

✅ Safe Pins to Use

For general GPIO usage, these are the safest and most flexible choices:

🔹 IO18

🔹 IO19

🔹 IO22

🔹 IO23

🔹 IO25

🔹 IO26

🔹 IO27

🔹 IO32

🔹 IO33

Why Are These Pins Safe?

Not involved in bootstrapping → No impact on device boot mode or system startup
Not linked to flash memory or PSRAM → Won't interfere with storage or memory access
Not dedicated to USB or JTAG → Free for general use without affecting debugging
No special hardware connections → Freely assignable without internal conflicts

⚠️ Pins to Avoid or Use with Caution

Some pins are reserved for critical functions like bootstrapping, JTAG debugging, USB communication, and flash memory operations. Misusing these pins may lead to boot failures, programming issues, USB conflicts, or disruptions in flash storage.

Critical Pin Categories:

🛠️ Strapping Pins: Control boot behavior and flash voltage selection
🔗 JTAG Debugging Pins: Required for low-level debugging
🔌 USB Communication Pins: Used for USB Serial/JTAG communication
⚡ Flash Memory & SPI Pins: Connected to SPI flash memory and PSRAM
📡 UART Serial Communication Pins: Used for debugging and firmware uploads

PIN	Label	Reason	Function
IO0	GPIO0	Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode.	🛠️ Strapping
IO2	GPIO2	If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure.	🛠️ Strapping
IO4	GPIO4	Sampled at reset for boot config; should not be driven at boot (affects boot mode timing).	🛠️ Strapping
IO5	GPIO5	Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot.	🛠️ Strapping
IO12	MTDI (GPIO12)	Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used.	🛠️ Strapping
IO13	MTCK (GPIO13)	Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.	🪛 Other
IO14	MTMS (GPIO14)	Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.	🪛 Other
IO15	MTDO (GPIO15)	Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.	🛠️ Strapping
IO16	GPIO16	Connected to internal PSRAM on PSRAM-enabled modules; not usable as GPIO on those modules.	⚡ Flash
IO17	GPIO17	Connected to internal PSRAM on PSRAM-enabled modules; not usable as GPIO on those modules.	⚡ Flash
IO34	GPIO34	Cannot be used as output (no drive capability); only suitable for analog/digital input.	🪛 Other
IO35	GPIO35	Cannot be used as output; only suitable for input.	🪛 Other
IO36	GPIO36 (SENSOR_VP)	Cannot be used as output; only suitable for input (e.g., analog read).	🪛 Other
IO39	GPIO39 (SENSOR_VN)	Cannot be used as output; only suitable for input.	🪛 Other

WEMOS LOLIN32 Lite Useful Links

🔗 Datasheet

https://megma.ma/wp-content/uploads/2021/08/Wemos-ESP32-Lolin32-Board-BOOK-ENGLISH.pdf?srsltid=AfmBOopqYIpvyfKiZkeRXz80LhmsueeRBiUmBe9y4W_2USehuxV0eAis

🔗 ESP32 Datasheet

https://www.espressif.com/sites/default/files/documentation/esp32_datasheet_en.pdf

WEMOS LOLIN32 Lite Pin Mappings

This development board provides 40 digital IO pins, out of which 16 can be used as external interrupt pins , 16 as analog input pins and 18 pins have Pulse-Width Modulation (PWM) .

Pin	Function	ESP Pin	Input/Output	Description
1	5V	5V	POWER INPUT	5V power input for the board
2	GND	GND	POWER GROUNT	Ground connection
3	3V3	3.3V	POWER OUTPUT	3.3V power output
5	IO0	GPIO0	BIDIRECTIONAL	GPIO, ADC
6	IO2	GPIO2	BIDIRECTIONAL	GPIO, ADC
7	IO4	GPIO4	BIDIRECTIONAL	GPIO, ADC
8	IO5	GPIO5	BIDIRECTIONAL	GPIO
9	IO12	GPIO12	BIDIRECTIONAL	GPIO, ADC
10	IO13	GPIO13	BIDIRECTIONAL	GPIO, ADC
11	IO14	GPIO14	BIDIRECTIONAL	GPIO, ADC
12	IO15	GPIO15	BIDIRECTIONAL	GPIO
13	IO16	GPIO16	BIDIRECTIONAL	GPIO
14	IO17	GPIO17	BIDIRECTIONAL	GPIO
15	IO18	GPIO18	BIDIRECTIONAL	GPIO
16	IO19	GPIO19	BIDIRECTIONAL	GPIO
17	IO22	GPIO22	BIDIRECTIONAL	GPIO
18	IO23	GPIO23	BIDIRECTIONAL	GPIO
19	IO25	GPIO25	BIDIRECTIONAL	GPIO, ADC
20	IO26	GPIO26	BIDIRECTIONAL	GPIO, ADC
21	IO27	GPIO27	BIDIRECTIONAL	GPIO, ADC
22	IO32	GPIO32	BIDIRECTIONAL	GPIO, ADC
23	IO33	GPIO33	BIDIRECTIONAL	GPIO, ADC
24	IO34	GPIO34	BIDIRECTIONAL	GPIO, ADC
25	IO35	GPIO35	BIDIRECTIONAL	GPIO, ADC
26	IO36	GPIO36	BIDIRECTIONAL	GPIO, ADC
27	IO39	GPIO39	BIDIRECTIONAL	GPIO, ADC

Function Pin Function

ESP Pin Pin on ESP32

I/O Input/Output Pin

Description Pin Description

WEMOS LOLIN32 Lite Pins Mapping Arduino IDE

Below you can find the WEMOS LOLIN32 Lite pinout. This development board provides 40 digital IO pins, out of which 16 can be used as external interrupt pins, 16 as analog input pins and 18 pins have Pulse-Width Modulation (PWM).

Pin	Analog	Touch	PWM	Other
0	A11	T1
1			PWM	TX
2	A12	T2	PWM
3			PWM	RX
4	A10	T0	PWM
5			PWM	SS
12	A15	T5	PWM
13	A14	T4	PWM
14	A16	T6	PWM
15	A13	T3	PWM
18			PWM	SCK
19			PWM	SDA MISO
22			PWM	LED_BUILTIN
23			PWM	SCL MOSI
25	A18		PWM	DAC1
26	A19		PWM	DAC2
27	A17	T7	PWM
32	A4	T9	PWM
33	A5	T8	PWM
34	A6
35	A7
36	A0
39	A3

Analog Analog input pins

Touch Touch pins

Function Function pins

RX / TX Receive/Transmit

LED_BUILTIN Built-in LED

PWM Pulse-Width Modulation

Default Tools

Bootloader tool	esptool_py
Uploader tool	esptool_py
Network uploader tool	esp_ota
Bootloader address	0x1000
Flash mode	dio
Boot mode	dio
Maximum upload size	1280 Kb (1310720 B)
Maximum data size	320 Kb (327680 B)

The WEMOS LOLIN32 Lite development board by default uses esptool_py uploader tool, esp_ota network uploader tool for Over-the-air (OTA) uploads and esptool_py bootloader tool. The bootloader starts at address "0x1000". Flash mode and boot mode for WEMOS LOLIN32 Lite development board by default is dio and dio respectively.