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Hemolock

An emergency kit for a medical-device team. Flip one switch, and it sends your GPS location and places a phone call.

RoleRebuilt the electronics & firmware
When2026
StackESP32 · NEO-6M GPS · Twilio
StatusWorking prototype
1switch to trigger
5scancellable countdown
2languages in every alert
3.7→5Vstable power from a LiPo
01 / The problem

A lost prototype
and a deadline.

A medical-device team lost their emergency-kit prototype and needed it working again. The idea was simple: in an emergency, one action should tell the right people where you are.

The hard parts were all physical: unstable power, firmware crashes and the real-world rules for placing automated calls in Jordan.

02 / How it works

One switch,
three things happen.

Switchflip to arm
Countdown5 seconds, cancellable
LocateGPS fix
AlertTelegram, Arabic and English
Callautomated via Twilio
03 / Decisions worth explaining

Why it’s
built this way.

01

A countdown you can cancel

An LED and buzzer start a 5-second countdown, so an accidental flip never sends a false alarm.

02

Bilingual by default

Every alert goes out in Arabic and English, with a Google Maps link to the exact location.

03

Stable power first

A 3.7V LiPo boosted to a stable 5V, because GPS and WiFi fail in strange ways on a sagging supply.

04

No blocking code

Watchdog crashes came from blocking buzzer tones. Rewriting them as non-blocking fixed the resets.

04 / What made it work

Hardware is
honest.

  • A working kit: switch, countdown, GPS fix, bilingual Telegram alert and automated calls.
  • Power and watchdog issues found and fixed at the root, not worked around.
  • Jordan’s high-risk call permissions handled, so automated calls actually connect.
  • Proof that I can take a system from firmware to the phone in someone’s pocket.

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