unPhone 7

Modular ESP32-based mobile platform - ideal for education, prototyping, and open-source phone development.

Micro-USB
unPhone 7 board
ESP32
MCU
240MHz
clock
4MB
flash
520KB
SRAM
21· 14 ADC
GPIO
BLE 4.2+ WiFi
radio
On this page

unPhone 7 Pinout

21 pins
PinGPIOLabelsStatusCapabilitiesNotes
14A5T0PWMsafeadc · touch
25SCKPWMstrappingspi
312A11T5PWMstrappingadc · touch
413LED_BUILTINA12T4PWMstrappingadc · touch
514A6T6PWMstrappingadc · touch
615A8T3PWMstrappingadc · touch
716RXPWMuartuart
817TXPWMuartuart
918MOSIPWMsafespi
1019MISOPWMsafespi
1122SCLPWMsafei2c
1223SDAPWMsafei2c
1325A1DAC1PWMsafeadc · dac
1426A0DAC2PWMsafeadc · dac
1527A10T7PWMsafeadc · touch
1632A7T9PWMsafeadc · touch
1733SSA9T8PWMsafeadc · touch · spi
1834A2strappingadc
1935BATT_MONITORA13strappingadc
2036A4strappingadc
2139A3strappingadc
21 GPIOs broken out 12 free · 9 need care · 0 to avoid

Start with these

12 pins with no boot or system involvement
A5GPIO4RXGPIO16TXGPIO17MOSIGPIO18MISOGPIO19SCLGPIO22SDAGPIO23A1GPIO25A0GPIO26A10GPIO27A7GPIO32SSGPIO33

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

Fine - with a little care

9 pins · 8 things to know
SCKGPIO5 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.

A11GPIO12 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.

LED_BUILTINGPIO13 JTAG clock pin (TCK); also ADC2 channel 4 / Touch4 input. JTAG

Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.

A6GPIO14 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.

A8GPIO15 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.

A2GPIO34 Input-only GPIO (no output driver); ADC1 channel 6. Other

Cannot be used as output (no drive capability); only suitable for analog/digital input.

BATT_MONITORGPIO35A3GPIO39 Input-only GPIOs with ADC1 channels - no output driver Other

Cannot be used as output; only suitable for input.

  • BATT_MONITORInput-only GPIO (no output driver); ADC1 channel 7.
  • A3Input-only GPIO (no output); ADC1 channel 3, Hall sensor VN.
A4GPIO36 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).

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.

The unPhone 7 pinout brings out 21 GPIO pins - every one of them usable in your project.

For peripherals, I²C is mapped to SDA on GPIO23 and SCL on GPIO22; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO17 and GPIO16 cover serial logging and flashing.

On the analog side there are 14 ADC-capable pins for sensors and battery monitoring, 8 capacitive-touch inputs and 2 true DAC outputs.

If you want zero surprises, A5, RX, TX, MOSI and 8 more are free of any such role - the safest first picks. 9 of the exposed pins carry boot-time or system duties on the ESP32 (SCK, A11, LED_BUILTIN and 6 more).

Getting started

flash your first firmware in ~2 minutes
Tool:
1
Connect over USB
Uses a CP2104 bridge - install the CP210x driver if no port appears. Not detected? Hold BOOT while plugging in.
2
Match & flash
Set the Tools options shown, then click Upload.
3
Verify it runs
GPIO4 toggles - wire an LED and resistor to it, or change the pin to your board's own LED.
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
// toggle GPIO4 - wire an LED and resistor to it
void setup() {
  pinMode(4, OUTPUT);
}
void loop() {
  digitalWrite(4, HIGH); delay(500);
  digitalWrite(4, LOW);  delay(500);
}
board to selectesp32dev⧉ copy
platformio.ini Copy
[env:unphone7]
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: esp32
  framework:
    type: esp-idf

# blink - GPIO4
output:
  - platform: gpio
    pin: 4
    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 0x1000 firmware.bin
--port = your /dev/tty* (macOS/Linux) or COMx (Windows).
Build details: sketch space 1310720 B · data 327680 B · DIO

Specifications

ESP32 · vs other ESP32 chips →
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
21 · 14
UART · I²C · SPI
3 · 2 · 2
PWM
16 channels
Power
USB
Micro-USB
Serial
CP2104
Boot address
0x1000
Electrical
Input
5V USB · 3.7V LiPo
Consumption
-
Regulator
-
Display
Screen
TFT · 3.5" · 320x480
Driver
HX8357
Touch
XPT2046
Flashing
Upload · OTA
esptool_py · esp_ota
Flash · Boot mode
DIO · DIO
Sketch · Data
1.25 MB · 320 KB
The unPhone 7 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.

Onboard you'll find a TFT 3.5" 320x480 display with touch, a microSD slot, LoRa (RFM95W), an LSM9DS1 IMU, an IR transceiver, battery charging via JST-PH 2.0, status LEDs (RGB status LED) and Left/Middle/Right buttons.

  • Based on the Adafruit HUZZAH32 Feather (ESP32)
  • TCA9555 I²C 16-bit GPIO expander
  • Vibration motor for haptic feedback
  • RGB status LED (driven via the IO expander)
  • Hardware power slide switch
  • Integrated ~1200mAh LiPo battery
  • Adafruit Feather form factor

Resources

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