MobileMash - ESP32 Phone Button Presser

A 3D-printable, ESP32-controlled servo harness for programmatically pressing phone buttons. Primary use case: booting phones into fastboot mode unattended.

Supported Phones

Phone	Status
Pixel 10 Pro	v1

How It Works

Two SG90 micro servos are mounted in a 3D-printed cradle that clips around the phone. Each servo has a small arm that presses a button (power, volume-down). An ESP32 dev board drives the servos and accepts commands over USB serial.

Fastboot Sequence

1. Force shutdown - Press and hold power for up to 30 seconds (or until told to release).
2. Enter fastboot - Hold volume-down, then briefly press power. Release when told or after a safety timeout.

Hardware BOM

Part	Qty	Notes
ESP32 DevKit v1 (or similar)	1	Any ESP32 board with USB
SG90 micro servo	2	9g, 180-degree
M2x8 self-tapping screws	4	Mount servos to cradle
Rubber/silicone bumper pads	2	Glue to servo arms for grip
USB-A to micro-USB cable	1	Power + data to ESP32
470uF electrolytic capacitor	1	Optional, across servo 5V/GND

Wiring

ESP32 GPIO 13 --> Power servo signal (orange)
ESP32 GPIO 14 --> Volume-down servo signal (orange)
ESP32 5V      --> Both servo VCC (red)
ESP32 GND     --> Both servo GND (brown)

Firmware

Built with PlatformIO (Arduino framework).

cd firmware
pio run -t upload

Serial Protocol (115200 baud)

Commands are newline-terminated ASCII:

Command	Description
PRESS_POWER <ms>	Press power button for <ms> milliseconds
PRESS_VOLDN <ms>	Press volume-down for <ms> milliseconds
FASTBOOT [shutdown_ms] [combo_ms]	Run full fastboot entry sequence
RELEASE_ALL	Immediately release all buttons
STATUS	Report current state
PING	Returns PONG

Responses are newline-terminated:

Response	Meaning
OK <detail>	Command accepted / completed
ERR <detail>	Error
STATE <json>	Status response
PONG	Ping reply

3D Printing

OpenSCAD source in cad/. Export STL and print with:

• Material: PLA or PETG
• Layer height: 0.2mm
• Infill: 20%+
• Supports: not required

Host Tool

pip install pyserial
python host/mobilemash_cli.py --port /dev/ttyUSB0 fastboot

License

Apache 2.0