ESP32 WiFi Ping Server for On-Prem Power Monitoring
What A minimal ESP32 web server that responds with “OK” when pinged. Used to detect on-prem power/network status in cloud-failover architectures. Use case: You have an on-prem server with cloud backup. Ping the ESP32 to know if power is up. If ping fails, start cloud backup. Components: ESP32 board WiFi connection (2.4GHz) ESP-IDF framework HTTP server responding on port 80 Why Failover detection: Cloud apps can ping this to know if on-prem is offline. Cheap: ESP32 costs $5-10. No need for UPS monitoring APIs or expensive hardware. Simple: Single endpoint (/) returns OK. No auth, no dependencies. Low power: ESP32 draws minimal current. Runs indefinitely. Reliable: No OS overhead. Boots in seconds after power restoration. Real scenario: On-prem PostgreSQL + cloud RDS standby. ESP32 sits on same network. Cloud Lambda pings every 30 seconds. If 3 consecutive failures, promote RDS and switch DNS. When ESP32 responds again, you know on-prem is back. ...