ESP32 Battery-Powered Audio Device — Full Design Package (PCB + Firmware + 3D Enclosure)
Budget: $750 – $1,500 USD
=======================================
OVERVIEW
=======================================
We need a complete design package for a standalone, battery-powered
audio device.
The device plays pre-recorded church bell audio files from a microSD
card at three scheduled times per day (6 AM, 12 PM, 6 PM). Purely
hardware-controlled — no app, no WiFi, no Bluetooth required for
operation.
We handle fabrication separately through JLCPCB. Your deliverables are
design files only.
=======================================
WHAT THE DEVICE DOES
=======================================
* Plays a 2-3 minute audio recording at user-selected times (6 AM,
12 PM, and/or 6 PM)
* 3 toggle switches to enable/disable each time independently
* Rotary switch to select from 8-12 audio files stored on microSD
* Volume rotary knob (off / low / med / high)
* Large mute button on top — stops playback immediately
* Soft LED glow activates during playback (visible through enclosure window)
* Time set via small LCD hidden under the base — set once, forget it
* Runs 1-2 years on 2-3 AA batteries using deep sleep between playback events
=======================================
TECHNICAL REQUIREMENTS
=======================================
* Microcontroller ........... ESP32 (WiFi/BT disabled for battery life)
* Real-Time Clock ........... DS3231 with coin cell backup
* Audio Output .............. I2S DAC/amp (MAX98357A or equiv.) + 3W speaker
* Storage ................... MicroSD slot for WAV/MP3 files
* Display ................... 4-digit 7-segment or 0.96" OLED (time
setting only)
* LED ....................... Warm white or amber LED, soft glow
during playback
* Power ..................... 2-3 AA batteries, deep sleep architecture
*** IMPORTANT — DESIGN FOR JLCPCB FABRICATION ***
Use components from JLCPCB's parts library whenever possible:
--> https://jlcpcb.com/parts
Prefer "Basic" parts over "Extended" to minimize assembly fees.
This is a hard requirement — it directly affects our manufacturing cost.
=======================================
ENCLOSURE
=======================================
3D-printed gothic cathedral miniature, approximately 4-8 inches tall.
Dark bronze/gold finish aesthetic (we handle post-processing).
Must integrate:
* Speaker grille disguised as gothic tracery or rose window
* LED glow visible through window/tracery openings
* Mute button access through top of enclosure
* Flat base for shelf/mantel display
* Keyhole slots on back for wall mounting
* Hinged or removable base panel for time-setting controls
We have concept renders to share with the selected freelancer.
=======================================
DELIVERABLES
=======================================
1. Complete schematic (KiCad preferred)
2. PCB layout — Gerbers, BOM, pick-and-place files formatted for JLCPCB
3. Firmware (Arduino or ESP-IDF) — clean, commented, deep sleep +
scheduled playback + LED control
4. 3D enclosure model (STL files) — gothic cathedral design,
printable on FDM/SLA
5. Bill of Materials with JLCPCB part numbers
6. Brief setup/user instructions
=======================================
BUDGET & TIMELINE
=======================================
Budget ............. $500 - $800 USD (fixed price)
Timeline ........... 3-4 weeks (propose your estimate with milestones)
=======================================
TO APPLY — INCLUDE THE FOLLOWING
=======================================
[x] A relevant ESP32 or embedded audio project you've completed
[x] Your approach to the deep sleep + RTC wake + audio playback cycle
[x] Confirmation you can design for JLCPCB's parts library
[x] A milestone breakdown with timeline
* SUGGESTED FREELANCER SETTINGS *
Category ........... Electronics & Microcontrollers
Skills ............. ESP32, Arduino, PCB Design, KiCad, Embedded
C/C++, 3D Modeling, Firmware
Budget ............. $500-$800 Fixed Price
Duration ........... 3-4 weeks
Experience ......... Intermediate to Expert
OVERVIEW
=======================================
We need a complete design package for a standalone, battery-powered
audio device.
The device plays pre-recorded church bell audio files from a microSD
card at three scheduled times per day (6 AM, 12 PM, 6 PM). Purely
hardware-controlled — no app, no WiFi, no Bluetooth required for
operation.
We handle fabrication separately through JLCPCB. Your deliverables are
design files only.
=======================================
WHAT THE DEVICE DOES
=======================================
* Plays a 2-3 minute audio recording at user-selected times (6 AM,
12 PM, and/or 6 PM)
* 3 toggle switches to enable/disable each time independently
* Rotary switch to select from 8-12 audio files stored on microSD
* Volume rotary knob (off / low / med / high)
* Large mute button on top — stops playback immediately
* Soft LED glow activates during playback (visible through enclosure window)
* Time set via small LCD hidden under the base — set once, forget it
* Runs 1-2 years on 2-3 AA batteries using deep sleep between playback events
=======================================
TECHNICAL REQUIREMENTS
=======================================
* Microcontroller ........... ESP32 (WiFi/BT disabled for battery life)
* Real-Time Clock ........... DS3231 with coin cell backup
* Audio Output .............. I2S DAC/amp (MAX98357A or equiv.) + 3W speaker
* Storage ................... MicroSD slot for WAV/MP3 files
* Display ................... 4-digit 7-segment or 0.96" OLED (time
setting only)
* LED ....................... Warm white or amber LED, soft glow
during playback
* Power ..................... 2-3 AA batteries, deep sleep architecture
*** IMPORTANT — DESIGN FOR JLCPCB FABRICATION ***
Use components from JLCPCB's parts library whenever possible:
--> https://jlcpcb.com/parts
Prefer "Basic" parts over "Extended" to minimize assembly fees.
This is a hard requirement — it directly affects our manufacturing cost.
=======================================
ENCLOSURE
=======================================
3D-printed gothic cathedral miniature, approximately 4-8 inches tall.
Dark bronze/gold finish aesthetic (we handle post-processing).
Must integrate:
* Speaker grille disguised as gothic tracery or rose window
* LED glow visible through window/tracery openings
* Mute button access through top of enclosure
* Flat base for shelf/mantel display
* Keyhole slots on back for wall mounting
* Hinged or removable base panel for time-setting controls
We have concept renders to share with the selected freelancer.
=======================================
DELIVERABLES
=======================================
1. Complete schematic (KiCad preferred)
2. PCB layout — Gerbers, BOM, pick-and-place files formatted for JLCPCB
3. Firmware (Arduino or ESP-IDF) — clean, commented, deep sleep +
scheduled playback + LED control
4. 3D enclosure model (STL files) — gothic cathedral design,
printable on FDM/SLA
5. Bill of Materials with JLCPCB part numbers
6. Brief setup/user instructions
=======================================
BUDGET & TIMELINE
=======================================
Budget ............. $500 - $800 USD (fixed price)
Timeline ........... 3-4 weeks (propose your estimate with milestones)
=======================================
TO APPLY — INCLUDE THE FOLLOWING
=======================================
[x] A relevant ESP32 or embedded audio project you've completed
[x] Your approach to the deep sleep + RTC wake + audio playback cycle
[x] Confirmation you can design for JLCPCB's parts library
[x] A milestone breakdown with timeline
* SUGGESTED FREELANCER SETTINGS *
Category ........... Electronics & Microcontrollers
Skills ............. ESP32, Arduino, PCB Design, KiCad, Embedded
C/C++, 3D Modeling, Firmware
Budget ............. $500-$800 Fixed Price
Duration ........... 3-4 weeks
Experience ......... Intermediate to Expert