TTGO T1

by LilyGo

Classic ESP32 TTGO board with LiPo support and headers - great for basic wireless development and IoT builds.

Micro-USB

Buy on AliExpress · $7.00 More sellers Pinout

ESP32

MCU

240MHz

clock

4MB

flash

520KB

SRAM

31· 16 ADC

GPIO

BLE 4.2+ WiFi

radio

Pinout

36 pins

View:

Pin	GPIO	Labels	Status	Capabilities	Notes
1	-	GND	ground	-	Ground
2	23	GPIO23MOSI	safe	spi	VSPI MOSI
3	22	GPIO22SCL	safe	i2c	Default I2C SCL, onboard LED (LED_BUILTIN)
4	1	GPIO1TX	uart	uart	UART0 TX
5	3	GPIO3RX	uart	uart	UART0 RX
6	21	GPIO21SDA	safe	i2c	Default I2C SDA
7	-	5V	power	-	5V from USB / power input
8	19	GPIO19MISO	safe	spi	VSPI MISO
9	18	GPIO18SCK	safe	spi	VSPI SCK
10	5	GPIO5SS	strapping	spi	VSPI SS
11	17	GPIO17	strapping	-	General-purpose IO
12	16	GPIO16	strapping	-	General-purpose IO
13	4	GPIO4	strapping	adc · touch	ADC2_CH0, Touch0
14	0	GPIO0	strapping	adc · touch	ADC2_CH1, Touch1
15	2	GPIO2SD MISO	strapping	adc · touch · spi	microSD MISO, ADC2_CH2, Touch2
16	15	GPIO15SD MOSI	strapping	adc · touch · spi	microSD MOSI, ADC2_CH3, Touch3
17	8	SD1GPIO8	strapping	-	Flash pin - do not use
18	7	SD0GPIO7	strapping	-	Flash pin - do not use
19	-	3V33.3V	power	-	3.3V regulated output
20	-	RSTEN	control	-	Chip enable / reset (active LOW)
21	36	SVPGPIO36	strapping	adc	ADC1_CH0, input only
22	39	SVNGPIO39	strapping	adc	ADC1_CH3, input only
23	34	GPIO34	strapping	adc	ADC1_CH6, input only
24	35	GPIO35	strapping	adc	ADC1_CH7, input only
25	32	GPIO32	safe	adc · touch	ADC1_CH4, Touch9
26	33	GPIO33	safe	adc · touch	ADC1_CH5, Touch8
27	25	GPIO25	safe	adc · dac	DAC1, ADC2_CH8
28	26	GPIO26	safe	adc · dac	DAC2, ADC2_CH9
29	27	GPIO27	safe	adc · touch	ADC2_CH7, Touch7
30	14	GPIO14SD SCK	strapping	adc · touch · spi	microSD SCK, ADC2_CH6, Touch6
31	12	GPIO12	strapping	adc · touch	ADC2_CH5, Touch5
32	-	GND	ground	-	Ground
33	13	GPIO13SD CS	strapping	adc · touch · spi	microSD CS, ADC2_CH4, Touch4
34	9	SD2GPIO9	strapping	-	Flash pin - do not use
35	10	SD3GPIO10	strapping	-	Flash pin - do not use
36	11	CMDGPIO11	strapping	-	Flash pin - do not use

Start with these

10 pins with no boot or system involvement

GPIO23MOSIGPIO22SCLGPIO21SDAGPIO19MISOGPIO18SCKGPIO32GPIO33GPIO25GPIO26GPIO27

Freely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.

Fine - with a little care

sampled at boot or shared with debug/serial

Pin	Label	What to know	Role
GPIO5	GPIO5	Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot.	Strapping
GPIO4	GPIO4	Sampled at reset for boot config; should not be driven at boot (affects boot mode timing).	Strapping
GPIO0	GPIO0	Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode.	Strapping
GPIO2	GPIO2	If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure.	Strapping
GPIO15	MTDO (GPIO15)	Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.	Strapping
SVP	GPIO36 (SENSOR_VP)	Cannot be used as output; only suitable for input (e.g., analog read).	Other
SVN	GPIO39 (SENSOR_VN)	Cannot be used as output; only suitable for input.	Other
GPIO34	GPIO34	Cannot be used as output (no drive capability); only suitable for analog/digital input.	Other
GPIO35	GPIO35	Cannot be used as output; only suitable for input.	Other
GPIO14	MTMS (GPIO14)	Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.	Other
GPIO12	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
GPIO13	MTCK (GPIO13)	Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.	Other

Only if you know the tricks

wired to flash or USB - expect a fight

Pin	Label	What to know	Role
GPIO1	U0TXD (GPIO1)	Connected to on-board USB-UART for uploading and logs; drives serial output at boot, so using as GPIO can disrupt programming or console.	USB
GPIO3	U0RXD (GPIO3)	Used for receiving data from USB-UART (programming); also pulled HIGH at boot for console communication, so using as GPIO can disrupt uploads.	USB
GPIO17	GPIO17	Connected to internal PSRAM on PSRAM-enabled modules; not usable as GPIO on those modules.	Flash
GPIO16	GPIO16	Connected to internal PSRAM on PSRAM-enabled modules; not usable as GPIO on those modules.	Flash
SD1	GPIO8 (Flash SD1)	Used for internal flash/PSRAM data; not available for general GPIO.	Flash
SD0	GPIO7 (Flash SD0)	Used for internal flash/PSRAM data; not available for general GPIO.	Flash
SD2	GPIO9 (Flash SD2)	Used by internal flash/PSRAM; typically not exposed on modules, avoid using as GPIO.	Flash
SD3	GPIO10 (Flash SD3)	Used by internal flash/PSRAM; typically not exposed on modules, avoid using as GPIO.	Flash
CMD	GPIO11 (Flash CMD)	Used by internal flash (chip select/command); not available for general use.	Flash

These are recommendations, not hard rules - with the right pull-ups, timing and boot-state awareness most pins can be made to work. When in doubt, start green.

Pinout notes The TTGO T1 breaks out 36 pins in total: 31 GPIO for your project, with GND , 5V and 3V3 handling power. For peripherals, I²C is mapped to SDA on GPIO21 and…

The TTGO T1 breaks out 36 pins in total: 31 GPIO for your project, with GND, 5V and 3V3 handling power.

For peripherals, I²C is mapped to SDA on GPIO21 and SCL on GPIO22; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO1 and GPIO3 cover serial logging and flashing.

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, GPIO23, GPIO22, GPIO21, GPIO19 and 6 more are free of any such role - the safest first picks. 12 of the exposed pins carry boot-time or system duties on the ESP32 (GPIO5, GPIO4, GPIO0 and 9 more).

Getting started

flash your first firmware in ~2 minutes

Tool:

Connect over USB

Install your USB-serial driver (CH340 / CP210x) if no port appears. Not detected? Hold BOOT while plugging in.

Match & flash

Set the Tools options shown, then click Upload.

Verify it runs

The onboard LED on GPIO23 blinks - swap the pin if your board's LED differs.

Set these in Tools · leave everything else at default

Arduino IDE 2.x — Tools Copy

Board: "ESP32 Dev Module"▸

Flash Size: "4MB (32Mb)"▸

Flash Mode: "DIO"▸

Partition Scheme: "Default 4MB with spiffs (1.2MB APP / 1.5MB SPIFFS)" (default)▸

Upload Speed: "921600"▸

▸ every other Tools option — leave at default

Board: 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

Find it: Tools ▸ Board ▸ ESP32 Arduino ▸ ESP32 Dev Module

blink.ino Copy

// blink the onboard LED
void setup() {
  pinMode(23, OUTPUT);
}
void loop() {
  digitalWrite(23, HIGH); delay(500);
  digitalWrite(23, LOW);  delay(500);
}

board to selectesp32dev⧉ copy

platformio.ini Copy

[env:ttgo-t1]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600

Find it: PlatformIO Home ▸ Boards, search esp32dev — or type it after board =.

board to selectesp32dev⧉ copy

device.yaml Copy

esp32:
  board: esp32dev
  variant: ttgo-t1
  framework:
    type: esp-idf

# blink - GPIO23
output:
  - platform: gpio
    pin: 23
    id: led_out
light:
  - platform: binary
    name: "LED"
    output: led_out

Find it: search ESPHome's board list for esp32dev (same ids as PlatformIO).

esptool doesn't pick board settings — a prebuilt .bin already has them baked in. This is just the raw flash command.

terminal Copy

esptool.py --chip esp32 --port /dev/ttyACM0 \
  --baud 921600 write_flash 0x0 firmware.bin

--port = your /dev/tty* (macOS/Linux) or COMx (Windows).

Build details: sketch space 1310720 B · data 327680 B · DIO

Specifications

ESP32

Compute

MCU

ESP32

Clock

240 MHz

SRAM · Flash

520 KB · 4MB

Radio

Wi-Fi

802.11 b/g/n

Bluetooth

4.2 LE

Antenna

PCB

I/O

GPIO · ADC

31 · 16

UART · I²C · SPI

3 · 2 · 4

PWM

16 channels

Power

USB

Micro-USB

Serial

CH340C

Boot address

0x1000

Flashing

Upload · OTA

esptool_py · esp_ota

Flash · Boot mode

DIO · DIO

Sketch · Data

1.25 MB · 320 KB

The TTGO T1 uses esptool_py for firmware uploads, esp_ota for over-the-air (OTA) updates. Flash mode is DIO with DIO boot mode. The maximum sketch size is 1.25 MB with 320 KB available for data.

About this board

At its core is the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.

Expect to pay about $7.00 - less than the ~$20 most ESP32 boards go for.

31 GPIO are broken out - more than most ESP32 boards, so the pin budget is rarely the constraint.

Onboard you'll find a microSD slot, battery charging via JST 1.25mm and Reset buttons.

Power on/off switch

Where to buy

prices are typical street prices

TTGO T1

$7.00per unit, typical

ALIAliExpress↗

Resources

ESP32 datasheet espressif.com↗ LilyGO ESP32-TTGO-T1 GitHub repository github.com↗LilyGO TTGO T1 V1.3 on LilyGO Official Store (AliExpress) aliexpress.com↗

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