ESP32 38-Pin DevKit (Generic Clone)
by Generic
Universal guide for identifying and using generic 38-pin ESP32 DevKit clones (DevKitC style, same pin order as the NodeMCU-32S).

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ESP32 38-Pin DevKit (Generic Clone) Pinout
38 pins
| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | - | 3V33.3V | power | - | 3.3V regulated output (~600mA max) |
| 2 | - | EN | control | - | Chip enable / reset (active LOW) |
| 3 | 36 | VPGPIO36A0 | strapping | adc | SENSOR_VP, ADC1_CH0, input only, no pull resistors |
| 4 | 39 | VNGPIO39A3 | strapping | adc | SENSOR_VN, ADC1_CH3, input only, no pull resistors |
| 5 | 34 | D34GPIO34A6 | strapping | adc | ADC1_CH6, input only, no pull resistors |
| 6 | 35 | D35GPIO35A7 | strapping | adc | ADC1_CH7, input only, no pull resistors |
| 7 | 32 | D32GPIO32A4 | safe | adc · touch | ADC1_CH4, Touch9 |
| 8 | 33 | D33GPIO33A5 | safe | adc · touch | ADC1_CH5, Touch8 |
| 9 | 25 | D25GPIO25A18 | safe | adc · dac | DAC1, ADC2_CH8 |
| 10 | 26 | D26GPIO26A19 | safe | adc · dac | DAC2, ADC2_CH9 |
| 11 | 27 | D27GPIO27A17 | safe | adc · touch | ADC2_CH7, Touch7 |
| 12 | 14 | D14GPIO14A16 | strapping | adc · touch · spi | ADC2_CH6, Touch6, HSPI_CLK |
| 13 | 12 | D12GPIO12A15 | strapping | adc · touch · spi | ADC2_CH5, Touch5, HSPI_MISO, Strapping pin (flash voltage) |
| 14 | - | GND | ground | - | Ground |
| 15 | 13 | D13GPIO13A14 | strapping | adc · touch · spi | ADC2_CH4, Touch4, HSPI_MOSI |
| 16 | 9 | SD2GPIO9 | strapping | - | Internal SPI flash (SD_DATA2) - not usable |
| 17 | 10 | SD3GPIO10 | strapping | - | Internal SPI flash (SD_DATA3) - not usable |
| 18 | 11 | CMDGPIO11 | strapping | - | Internal SPI flash (SD_CMD) - not usable |
| 19 | - | VIN5V | power | - | 5V input to onboard regulator |
| 20 | - | GND | ground | - | Ground |
| 21 | 23 | D23GPIO23 | safe | spi | VSPI_MOSI |
| 22 | 22 | D22GPIO22 | safe | i2c | I2C_SCL (default) |
| 23 | 1 | TX0GPIO1 | uart | uart | UART0 TX (USB serial) |
| 24 | 3 | RX0GPIO3 | uart | uart | UART0 RX (USB serial) |
| 25 | 21 | D21GPIO21 | safe | i2c | I2C_SDA (default) |
| 26 | - | GND | ground | - | Ground |
| 27 | 19 | D19GPIO19 | safe | spi | VSPI_MISO |
| 28 | 18 | D18GPIO18 | safe | spi | VSPI_CLK |
| 29 | 5 | D5GPIO5 | strapping | spi | VSPI_CS, Strapping pin |
| 30 | 17 | TX2GPIO17 | uart | uart | UART2 TX |
| 31 | 16 | RX2GPIO16 | uart | uart | UART2 RX |
| 32 | 4 | D4GPIO4A10 | safe | adc · touch | ADC2_CH0, Touch0 |
| 33 | 0 | D0GPIO0A11 | strapping | adc · touch | ADC2_CH1, Touch1, Boot button (strapping pin) |
| 34 | 2 | D2GPIO2A12 | strapping | adc · touch | ADC2_CH2, Touch2, on-board LED, Strapping pin |
| 35 | 15 | D15GPIO15A13 | strapping | adc · touch · spi | ADC2_CH3, Touch3, HSPI_CS, Strapping pin |
| 36 | 8 | SD1GPIO8 | strapping | - | Internal SPI flash (SD_DATA1) - not usable |
| 37 | 7 | SD0GPIO7 | strapping | - | Internal SPI flash (SD_DATA0) - not usable |
| 38 | 6 | CLKGPIO6 | strapping | - | Internal SPI flash (SD_CLK) - not usable |
Start with these
13 pins with no boot or system involvementFreely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.
Fine - with a little care
13 pins · 12 things to knowVPGPIO36 Input-only GPIO (no output); ADC1 channel 0, Hall sensor VP. Other
Cannot be used as output; only suitable for input (e.g., analog read).
VNGPIO39D35GPIO35 Input-only GPIOs with ADC1 channels - no output driver Other
Cannot be used as output; only suitable for input.
- VNInput-only GPIO (no output); ADC1 channel 3, Hall sensor VN.
- D35Input-only GPIO (no output driver); ADC1 channel 7.
D34GPIO34 Input-only GPIO (no output driver); ADC1 channel 6. Other
Cannot be used as output (no drive capability); only suitable for analog/digital input.
D14GPIO14 JTAG mode select pin (TMS); also HSPI CLK and PWM-capable GPIO. JTAG
Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.
D12GPIO12 Bootstrapping pin; JTAG TDI; sets flash voltage (VDD_SDIO); also HSPIQ (flash data line). Strapping
Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used.
D13GPIO13 JTAG clock pin (TCK); also ADC2 channel 4 / Touch4 input. JTAG
Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.
TX0GPIO1 Default UART0 TX pin for USB-serial programming and console. UART
Connected to on-board USB-UART for uploading and logs; drives serial output at boot, so using as GPIO can disrupt programming or console.
RX0GPIO3 Default UART0 RX pin for USB-serial programming (console input). UART
Used for receiving data from USB-UART (programming); also pulled HIGH at boot for console communication, so using as GPIO can disrupt uploads.
D5GPIO5 Bootstrapping pin; internal pull-up; VSPI CS0 (default SPI chip-select); acts as FSPIWP (flash write-protect) on internal-flash variants. Strapping
Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot.
D0GPIO0 Bootstrapping pin (enter bootloader when low); internal pull-up. Strapping
Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode.
D2GPIO2 Bootstrapping pin (must be low or floating at reset); internal pull-down. Strapping
If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure.
D15GPIO15 Bootstrapping pin; JTAG TDO; controls UART0 boot log output; also HSPICS0 (secondary SPI CS). Strapping
Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.
Only if you know the tricks
6 pins · 4 things to knowSD2GPIO9SD3GPIO10 SPI flash/PSRAM data lines SD2 and SD3 (flash HOLD and WP) Flash
Used by internal flash/PSRAM; typically not exposed on modules, avoid using as GPIO.
- SD2Connected to SPI flash/PSRAM data 2 (SD2, flash HOLD).
- SD3Connected to SPI flash/PSRAM data 3 (SD3, flash WP).
CMDGPIO11 Connected to SPI flash command/CS (CMD/CS0). Flash
Used by internal flash (chip select/command); not available for general use.
SD1GPIO8SD0GPIO7 SPI flash data lines SD0 and SD1 Flash
Used for internal flash/PSRAM data; not available for general GPIO.
- SD1Connected to SPI flash data 1 (SD1).
- SD0Connected to SPI flash data 0 (SD0).
CLKGPIO6 Connected to SPI flash clock (SCK/CLK). Flash
Used for internal flash/PSRAM communication; not available for general GPIO.
The ESP32 38-Pin DevKit (Generic Clone) breaks out 38 pins in total: 32 GPIO for your project, with 3V3, GND and VIN handling power.
On the analog side there are 16 ADC-capable pins for sensors and battery monitoring, 10 capacitive-touch inputs and 2 true DAC outputs.
If you want zero surprises, D32, D33, D25, D26 and 9 more are free of any such role - the safest first picks. 13 of the exposed pins carry boot-time or system duties on the ESP32 (VP, VN, D34 and 10 more).
Pinout notes Universal 38-Pin Layout (DevKitC / NodeMCU-32S Pin Order) This pinout matches most 38-pin ESP32 development boards, including NodeMCU-32S and wider ESP32…
Universal 38-Pin Layout (DevKitC / NodeMCU-32S Pin Order)
This pinout matches most 38-pin ESP32 development boards, including NodeMCU-32S and wider ESP32 DevKit clones.
Critical Boot Pins (Strapping Pins):
- GPIO0 - Boot mode: HIGH = normal boot, LOW = download/flash mode
- GPIO2 - Must be LOW or floating during boot (has onboard LED)
- GPIO12 - Flash voltage: LOW = 3.3V (default), HIGH = 1.8V
- GPIO15 - Debug output: LOW = normal (HIGH can cause boot failure)
Power
- VIN: 5V input (powers regulator)
- USB: 5V Micro-USB
- 3V3 Out: ~600mA max
- GPIO: 40mA/pin max
Serial
- UART0: TX=GPIO1, RX=GPIO3
USB programming - UART1: TX=GPIO10, RX=GPIO9
Flash pins - avoid - UART2: TX=GPIO17, RX=GPIO16
Available for sensors
I2C & SPI
- I2C: SDA=GPIO21, SCL=GPIO22
Software configurable - VSPI: MOSI=23, MISO=19, CLK=18, CS=5
- HSPI: MOSI=13, MISO=12, CLK=14, CS=15
Analog & Touch Capabilities
Use these when WiFi is active
Not reliable with WiFi
8-bit digital-to-analog
No external components needed
Do NOT Use These Pins:
- GPIO6-11: Connected to internal SPI flash - will cause boot failure
- These pins are exposed on 38-pin boards but should never be used in your projects
Pro Tips:
- Always use
ADC1channels (GPIO32-39) if WiFi is active - Never use GPIO6-11 - they're connected to flash memory
- GPIO34-39 are input-only (no internal pull-up/down resistors)
- Use external pull-up resistors on I2C lines (4.7kΩ typical)
- Most 38-pin boards have an onboard LED on GPIO2
- VIN pin allows powering the board from external 5V without USB
Getting started
flash your first firmware in ~2 minutesBoard: ESP32 Dev Module Flash Size: 4MB (32Mb) Flash Mode: DIO Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS) Upload Speed: 921600
// toggle GPIO32 - wire an LED and resistor to it
void setup() {
pinMode(32, OUTPUT);
}
void loop() {
digitalWrite(32, HIGH); delay(500);
digitalWrite(32, LOW); delay(500);
}[env:esp32-38pin-devkit-generic]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600esp32dev - or type it after board =.esp32:
board: esp32dev
variant: esp32
framework:
type: esp-idf
# blink - GPIO32
output:
- platform: gpio
pin: 32
id: led_out
light:
- platform: binary
name: "LED"
output: led_outesp32dev (same ids as PlatformIO).esptool.py --chip esp32 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x1000 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Downloads
Free for non-commercial use, credit espboards.dev · LicenseBoard illustration
The bare ESP32 38-Pin DevKit (Generic Clone) board drawn to scale at 48.26 × 27.94 mm, with no pin labels on it. Made for slide decks, wiring diagrams and project write-ups where a photo is too busy. Take the scalable SVG for print or editing, the high-resolution PNG to drop straight in, or the transparent PNG when you need it with no background behind it.
Pinout diagram
Every pin on both sides of the board with its functions, drawn by ESPboards from the ESP32 Series Datasheet v5.3 - the same sheet shown at the top of this page. The PNG is a high-resolution image for screens, the SVG is vector so it stays sharp at any size, and the PDF is laid out to print on A4 or Letter.
Yours to use, share and adapt for non-commercial work, as long as you credit espboards.dev - the full terms and ready-made credit lines are here.
Specifications
ESP32 · 48.26 × 27.94 mm · vs other ESP32 chips →Dimensions

About this board
At its core is the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.
Expect to pay about $4.00 - less than the ~$20 most ESP32 boards go for.
32 GPIO are broken out - more than most ESP32 boards, so the pin budget is rarely the constraint.
Onboard you'll find EN/Boot buttons.
The ESP32 38-Pin DevKit is a wider variant of the ESP32 development board commonly found on AliExpress, eBay, and Amazon. These boards copy Espressif's ESP32-DevKitC, with the two header rows 1.0 in (25.4 mm) apart, often print "ESP32_DevKitC_V4" or "ESP32-WROOM-32" on the silkscreen, and offer more exposed GPIO pins than the 30-pin variant. The narrower 0.9 in board sold as the NodeMCU-32S has the same 38-pin order.
How to Identify Which Board You Have
1. Check the USB-to-Serial ChipLook near the USB port for a square or rectangle IC with one of these labels:
- CH340C / CH340G → Most common on cheap clones. Rectangle chip. {% image "images/ch340c.png", "CH340C on ESP32 30pin Development Board", [500], "auto", "rounded-lg my-4", "max-width: 500px; width: 100%; height: auto;", true, true %}
- CP2102 → Common on mid-range boards. Square chip. {% image "images/cp2102-nodemcu-32s.png", "CP2102 on ESP32 30pin Development Board", [500], "auto", "rounded-lg my-4", "max-width: 500px; width: 100%; height: auto;", true, true %}
- CH9102F → Newer chip, similar to CP2102. Square chip. {% image "images/cp2102-vs-ch9102.png", "CP2102 vs CH9102 on ESP32 30pin Development Board", [500], "auto", "rounded-lg my-4", "max-width: 500px; width: 100%; height: auto;", true, true %}
- FT232RL → Less common but still found. Rectangle chip.
If you want to know more about USB-to-Serial chips, check out this detailed guide.
2. Count the Pins38-pin boards are wider DevKitC-style boards with 19 pins per side.
If you have 30 pins, check out the 30-pin variant guide instead.
- AMS1117 → Older clones (gets hot under load)
- Usually comes in a larger SOT-223 package with a flat metal tab (heatsinkable)
- Often has "AMS1117" or "1117/3.3" printed directly on the chip
- If you see a chunky 3-lead component with a metal tab near the USB port, it's likely AMS1117
- ME6211 / HT7333 → Newer low-dropout regulators (better efficiency)
- Typically comes in small SOT-89 or SOT-23 packages (much smaller than SOT-223)
- If it's a tiny 3-pin SMD component next to the input capacitors, it's likely HT7333
- May have short marking codes that are harder to read
Tip: Some boards print the regulator type on the silkscreen (check the board's underside or near the regulator for labels like "AMS1117" or "HT7333").
4. Look for Common LabelsMany 38-pin boards are labeled as:
- NodeMCU-32S → Very common CP2102-based board, but narrower (rows 0.9 in apart) - see the NodeMCU-32S page
- ESP32 DevKit V1 → Generic label, various USB chips
- ESP-WROOM-32 → Refers to the WiFi module, not the board itself
Key Advantages Over 30-Pin Boards
- More GPIOs exposed: 38 pins vs 30 pins means access to GPIO6-11 (though still not recommended for general use)
- VIN pin exposed: Can power from external 5V source without USB
- DevKitC pin order: Same header order and 1.0 in (25.4 mm) row spacing as Espressif's ESP32-DevKitC
- More ground pins: Better for power distribution in complex projects
Important Notes
- 38 pins total → More GPIOs than 30-pin variant, but still avoid GPIO6-11 (flash pins)
- Some boards label ADC pins as
VP,VN,SVP,SVNinstead of GPIO numbers - Driver installation required for CH340 chips (automatic on most modern systems)
- Strapping pins (GPIO0, GPIO2, GPIO12, GPIO15) must be in correct state during boot
- Wider board requires more breadboard space (may not fit standard 400-point breadboards)
Where to buy
prices are typical street prices
Resources
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