NFC-Based Children's Audio Player Development - 14/02/2026 07:36 EST
Budget: €30 – €250 EUR
Project Description
I am developing an educational NFC-based audio player for children (ages 2–7).
The concept is simple: a child places an NFC figurine on the box, and an associated audio story is played.
The project already has a custom PCB prototype (ESP32-based) and early firmware work, but I am looking for a new freelancer to take over, audit the existing work, and complete a fully functional prototype.
This is a serious product project, not an experiment.
What Already Exists:
I will provide a structured project folder including:
Custom PCB files (Gerber, BOM, Pick & Place, STEP file)
PCB size: 80 × 80 mm
ESP32-based design
NFC reader integrated
MicroSD slot
Battery charging circuit (Li-ion)
USB-C
Speaker output + headphone jack
NFC detection already demonstrated via serial console (video available)
Partial firmware work (NFC UID detection)
Your Mission
Phase 1 – Audit & Validation
Review existing PCB design files
Review firmware status
Identify what works and what needs fixing
Confirm if PCB can be used as-is or needs revision
Phase 2 – Firmware Completion
Complete ESP32 firmware:
NFC tag reading
Mapping NFC UID → audio file
MP3 playback from microSD
Speaker + headphone output
Basic button handling (play/pause, volume)
Ensure stable and testable behavior
Phase 3 – Functional Prototype
Guide or validate final wiring (speaker, battery, SD)
Provide clear testing instructions
Deliver:
Working firmware
Demo video of the prototype in action
Clear documentation
Important:
No upfront hardware purchases at your own expense.
All costs must be approved before any spending.
Deliverables
Firmware source code
Clear setup & testing documentation
Demo video showing:
NFC tag detection
Audio playback
Confirmation of prototype readiness for enclosure integration
Budget
$50–150 USD, depending on experience and scope after audit
(Milestones only – escrow-based)
Ideal Freelancer Profile
Strong experience with ESP32
NFC (RC522 / PN532 or similar)
Audio playback (I2S / DAC / SD card)
Comfortable reading existing PCB designs
Clear communicator
Professional and transparent with costs
Portfolio or examples of similar electronics projects required
Nice to Have (Not Mandatory)
Experience with children’s electronic products
Understanding of low-power / battery devices
How to Apply
Please include:
Brief introduction
Relevant experience (ESP32 / NFC / audio)
Examples or portfolio
Your approach for taking over an existing project
Physical Prototype & Shipping (Mandatory)
The final deliverable of this project includes at least one fully assembled and tested physical PCB prototype.
This means:
The freelancer must either already have the assembled PCB or
Receive it, assemble missing components if needed, test it, and
Ship at least one fully working prototype to me at the end of the project.
Shipping of the physical prototype is mandatory and must include:
1 fully functional PCB
Any remaining PCBs from the initial batch (if applicable)
Proper packaging
Shipping costs will be paid by me, but must be discussed and approved in advance.
No milestone will be released without:
Video proof of the working physical prototype
Confirmation of shipment (tracking number)
If you cannot handle physical assembly and shipping, please do not apply.
Required skills:
ESP32 embedded development
NFC / RFID (RC522, PN532, UID reading)
Embedded audio (MP3 playback, I2S/DAC, amplifier, speaker)
Firmware development & debugging
Hardware testing on real PCBs
Nice to have:
PCB review & BOM validation
Battery management (Li-ion)
Experience with physical product prototyping
Note
This project already went through one iteration with another freelancer.
I am looking for someone reliable, structured, and professional to move forward cleanly.
I am developing an educational NFC-based audio player for children (ages 2–7).
The concept is simple: a child places an NFC figurine on the box, and an associated audio story is played.
The project already has a custom PCB prototype (ESP32-based) and early firmware work, but I am looking for a new freelancer to take over, audit the existing work, and complete a fully functional prototype.
This is a serious product project, not an experiment.
What Already Exists:
I will provide a structured project folder including:
Custom PCB files (Gerber, BOM, Pick & Place, STEP file)
PCB size: 80 × 80 mm
ESP32-based design
NFC reader integrated
MicroSD slot
Battery charging circuit (Li-ion)
USB-C
Speaker output + headphone jack
NFC detection already demonstrated via serial console (video available)
Partial firmware work (NFC UID detection)
Your Mission
Phase 1 – Audit & Validation
Review existing PCB design files
Review firmware status
Identify what works and what needs fixing
Confirm if PCB can be used as-is or needs revision
Phase 2 – Firmware Completion
Complete ESP32 firmware:
NFC tag reading
Mapping NFC UID → audio file
MP3 playback from microSD
Speaker + headphone output
Basic button handling (play/pause, volume)
Ensure stable and testable behavior
Phase 3 – Functional Prototype
Guide or validate final wiring (speaker, battery, SD)
Provide clear testing instructions
Deliver:
Working firmware
Demo video of the prototype in action
Clear documentation
Important:
No upfront hardware purchases at your own expense.
All costs must be approved before any spending.
Deliverables
Firmware source code
Clear setup & testing documentation
Demo video showing:
NFC tag detection
Audio playback
Confirmation of prototype readiness for enclosure integration
Budget
$50–150 USD, depending on experience and scope after audit
(Milestones only – escrow-based)
Ideal Freelancer Profile
Strong experience with ESP32
NFC (RC522 / PN532 or similar)
Audio playback (I2S / DAC / SD card)
Comfortable reading existing PCB designs
Clear communicator
Professional and transparent with costs
Portfolio or examples of similar electronics projects required
Nice to Have (Not Mandatory)
Experience with children’s electronic products
Understanding of low-power / battery devices
How to Apply
Please include:
Brief introduction
Relevant experience (ESP32 / NFC / audio)
Examples or portfolio
Your approach for taking over an existing project
Physical Prototype & Shipping (Mandatory)
The final deliverable of this project includes at least one fully assembled and tested physical PCB prototype.
This means:
The freelancer must either already have the assembled PCB or
Receive it, assemble missing components if needed, test it, and
Ship at least one fully working prototype to me at the end of the project.
Shipping of the physical prototype is mandatory and must include:
1 fully functional PCB
Any remaining PCBs from the initial batch (if applicable)
Proper packaging
Shipping costs will be paid by me, but must be discussed and approved in advance.
No milestone will be released without:
Video proof of the working physical prototype
Confirmation of shipment (tracking number)
If you cannot handle physical assembly and shipping, please do not apply.
Required skills:
ESP32 embedded development
NFC / RFID (RC522, PN532, UID reading)
Embedded audio (MP3 playback, I2S/DAC, amplifier, speaker)
Firmware development & debugging
Hardware testing on real PCBs
Nice to have:
PCB review & BOM validation
Battery management (Li-ion)
Experience with physical product prototyping
Note
This project already went through one iteration with another freelancer.
I am looking for someone reliable, structured, and professional to move forward cleanly.