At 1 MHz the timer ISR fired every 240 CPU cycles (ESP32-S3 @ 240 MHz). ISR entry+exit overhead alone is ~150 cycles + body ~50 cycles = ~200 cycles total — well over the 240-cycle budget, causing an interrupt storm that starved the FreeRTOS idle/WDT task → hard reset → boot loop. 500 kHz gives a 2 µs / 480-cycle period, ~60% headroom over ISR time. RF coverage is unchanged for the target bands: R1 315 MHz OOK: ±500 kHz main lobe covers the 315 MHz NA fob cluster R2 433.46 MHz 2-FSK 380 kHz dev: tone pair 433.08–433.84 + sidebands fully spans 433–433.92 MHz Made-with: Cursor
4.8 KiB
4.8 KiB