Show HN: Show HN: I built a fail-closed watchdog for ESP32/Arduino in C++
Summary
Qrystal Uplink SDKs provide official ESP32/Arduino support for IoT device monitoring via heartbeat signals. The repository offers three SDKs (Arduino/C++, Native ESP-IDF, MicroPython) with features like TLS encryption, connection pooling, and NTP time synchronization, plus a simple heartbeat API and an API reference with status codes. It is MIT-licensed and includes setup guidance and documentation for practical, cross-platform deployment.