Debugging stale readings

Trace stale or missing home page values from probe to relay to dashboard mapping.

Stale readings mean the website shows an old temperature while the garage has moved on—or shows nothing while the LCD still updates. Work from the sensor outward: hardware, JSON, cache, SSR fetch, then history.

Checklist

  1. curl the feed URL from outside your LAN—is JSON fresh?
  2. Compare LCD vs JSON—if LCD wins, fix relay or Redis TTL.
  3. Verify probe keys in dashboard match schema—probe mapping.
  4. Inspect Cloudflare / SSR logs for timeout patterns.

Hardware-side causes

Watchdog reboots cause short gaps. DHT22 errors drop keys from JSON. Ethernet: wiring troubleshooting.

History vs live

Charts can lag if inserts stop but home page still looks live—check history inserts separately from home page fetch.