Building a Basketball Hoop Alarm Clock

Week 1 — Requirements and feasibility.

We tested the VL53L1X against a real basketball to check detection reliability. Early results were noisy; we tightened the field of view with a 3D printed baffle and got clean readings.

Week 2 — Schematic and first PCB.

Drew the schematic in KiCad, laid out a 4-layer board with a solid ground plane. Sent to JLCPCB for a five-piece run.

Week 3 — Firmware skeleton.

Got Zephyr running on the dev kit, brought up the RTC and I2S audio. Confirmed the alarm tone played at the target volume.

Week 4 — Sensor integration.

Wired the VL53L1X over I2C, wrote the detection state machine, tuned thresholds with real shots. Hit 97% detection accuracy across 200 test shots — misses were mostly soft layups that barely crossed the zone.

Week 5 — PCB assembly and bring-up.

Boards arrived, assembled one by hand. Found a footprint error on the RTC — fixed with a rework and a revised layout.

Week 6 — Enclosure and integration.

Printed the enclosure, mounted the sensor and speaker, ran the full system on battery. Got 23 days of standby on a single charge with the alarm firing once daily.

Week 7 — Field testing and polish.

Gave it to the client for two weeks of real use. He missed two alarms in that time, both on purpose to test the volume ramp.