Booting interface
Hardware + software, designed together
A pocket system, not a single-purpose gadget.
ESP32 DoomsDay is a compact field computer with physical controls, removable storage, modular buses, offline-first software, and a capability-based app runtime.
0MHz dual-core
0px color TFT
0mAh battery
0pin header
Drag to rotate
Full spec sheet below
Every port, bus, and byte.
Full spec sheet
Every number, out in the open.
No marketing rounding — these are the parts on the reference board.
ProcessorESP32-S3FH4R2, dual-core LX7 up to 240 MHz
Memory4 MB QIO flash + 2 MB QSPI PSRAM
Display128 × 128 color TFT with PWM backlight
Wireless2.4 GHz Wi-Fi + Bluetooth Low Energy
StorageRemovable microSD for apps, maps, data, and updates
Expansion7-pin SPI / I²C / UART accessory header
Power500 mAh LiPo, battery sensing, deep-sleep soft power
USBNative USB CDC/JTAG and wired power
Industrial design
Controls you can find without looking down.
DoomsDay OS
A visual system designed for a genuinely small screen.
The interface owns navigation, status, permissions, power, storage, networking, and updates. Apps get a predictable drawing surface while the operating system keeps the device understandable.
Multiple menu and lock-screen layouts
Per-capability app permissions
Explicit radio lifecycle
Transactional SD installs
08/08/26 · 21:4282%
Scan
Map
Apps
Weather
Files
Settings
BLE
Sensors
Power
SPI / I²C / UARTExpansion by design
Choose a module. See the pins. Run a focused test.
The header is not locked to one radio. GPS uses UART. Sensors can use I²C. Radios and displays can use SPI. Shared resources are mediated by the firmware so module sessions do not quietly fight the SD card or wireless stack.
Offline navigation
Take only the maps you need—and every detail that matters.
Build multiple city or trail-area packages on Windows, place them on microSD, and let live GPS coordinates select the package that covers your position. Pan, zoom, record tracks, and use a high-contrast night palette without a data connection.
Go deeper