ESP32 Low-Power Audio Device — PCB Desig

Building a Catholic Prayer Chime Device — Electronics Design Phase
We are developing The Angelus Chime, a battery-powered devotional device that plays authentic church bell recordings at 6 AM, 12 PM, and 6 PM. This is Phase 1 focusing exclusively on electronics design.
IMPORTANT: This engagement delivers DIGITAL FILES ONLY — No physical prototypes, no assembly, no enclosure work.
DEVICE OVERVIEW
A sacred object for the home — a device that rings real church bells three times a day, as they have for 700 years across Europe. No app, no WiFi, no Bluetooth. Just bells.
CORE FUNCTIONALITY
Plays 2-3 minute church bell recordings at prayer times
3 toggle switches for each prayer hour
Rotary switch for 8-12 bell recordings on SPI flash
Volume control + large mute button
Time set via small hidden display
Target: 1+ year battery life on 3-4 AA batteries (deep sleep)
TECHNICAL REQUIREMENTS
MCU: ESP32 (WiFi/BT disabled for battery life)
RTC: DS3231 with coin cell backup
Audio: I2S DAC/amp (MAX98357A or better) — audio quality is CRITICAL
Storage: SPI flash W25Q128 (16MB) for WAV/MP3
Controls: Rotary switches, toggles, push buttons, mute button
Display: 4-digit 7-segment or 0.96" OLED (hidden, time setting only)
Power: 3-4 AA batteries, deep sleep architecture
CRITICAL: JLCPCB OPTIMIZATION — Must use components from JLCPCB parts library. Prefer "Basic" parts over "Extended".
DELIVERABLES
Complete schematic files (KiCad preferred)
PCB layout files
JLCPCB manufacturing files (Gerbers, NC Drill, Pick-and-place)
Bill of Materials with verified JLCPCB part numbers
Firmware source code (Arduino or ESP-IDF) — deep sleep + RTC wake + I2S audio
Documentation and setup guide
Cost estimate for 100-unit production run
Design review session (video call)
BUDGET: $800–$1,200 USD fixed price (milestone-based)
TIMELINE: 2–4 weeks
TO APPLY — MUST INCLUDE:
ESP32 project portfolio (show a custom PCB project)
Technical approach to deep sleep + RTC wake + I2S audio
JLCPCB experience confirmation
Milestone breakdown with cost
Verification phrase: Include ANGELUS-ESP32 in your proposal
This is a well-funded, carefully planned product launch. Looking for a technical partner who takes pride in clean, professional work. Questions encouraged.
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