Sub-Microsecond GPS-Disciplined RTC with ESP32 - Kit
ESP32 GPS-Disciplined Precision RTC with OLED Sync Display
Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.
Sub-microsecond timing is no longer the preserve of expensive laboratory gear. This kit uses the GPS PPS (pulse-per-second) signal to discipline a DS3231 RTC, achieving clock accuracy within tens of nanoseconds of UTC. The ESP32 reads the GPS module, applies a real-time correction algorithm, and drives a crisp OLED display showing synchronization status, holdover duration, and current time deviation.
What You'll Build
You'll assemble a stand-alone system that locks onto GPS satellites, extracts the precise 1PPS edge, and continuously adjusts the DS3231's aging register to maintain sub-microsecond agreement with the satellite constellation. The completed unit sits in a compact enclosure, ready to serve as a stratum-1 time source for an NTP server, a test-instrument calibrator, or a reference clock for long-duration data logging where every microsecond counts.
What You'll Learn
- Implement GPS PPS-based disciplining of a temperature-compensated RTC in embedded C++
- Configure the NEO-6M's timepulse output and parse serial NMEA sentences
- Derive a stable holdover algorithm that predicts drift when GPS is unavailable
- Design an I�C-driven OLED dashboard showing live sync metrics and error histograms
Kit Contents
| Component | Quantity |
|---|---|
| ESP32 Dev Board | 1 |
| NEO-6M GPS | 1 |
| DS3231 RTC | 1 |
| 0.96in OLED | 1 |
| 4.7k? Resistors | 5 |
| 100nF Capacitors | 10 |
| PCB Prototype Board | 2 |
| 5V 2A Power Supply | 1 |
| Enclosure Box | 1 |
| Soldering Iron | 1 |
| Solder Wire | 1 |
Why Buy This Kit Instead of Sourcing Parts Separately
| Factor | Sourcing Separately | Compoden Kit |
|---|---|---|
| Compatibility checks | You verify every part | Pre-tested as a system |
| Build support | Forums and scattered tutorials | AI companion trained on this exact project |
| Time to first working build | Days of debugging | Hours, with step-by-step guidance |
| Shipping coordination | Multiple sellers, multiple delays | One shipment from Bengaluru in 3-5 days |
Who This Kit Is For
This kit is designed for B.Tech ECE/EEE students and researchers who need a reliable time-reference for Smart India Hackathon-type challenges, IoT testbeds, or end-semester projects. It's equally valuable for hobbyists prototyping at IIT/NIT/VIT/BITS labs and for anyone building a stratum-1 NTP server on a tight timeline. If you've worked with Arduino or ESP32 before and are ready to tackle precision timing, the 5-6 hour build delivers a laboratory-grade instrument you'll keep on your bench.
Built and Backed by Compoden
Every Compoden kit ships with an AI build companion trained on this exact project - accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.
What if I get stuck during the build?
Scan the box QR code to open the AI companion specific to this kit. It will step you through firmware and wiring, and you can send screenshots over WhatsApp for a direct engineer response within hours.
How accurate is the clock after GPS sync?
With a clean PPS signal and proper DS3231 aging register tuning, the drift stays under 1 microsecond while GPS lock is maintained. The AI companion includes real-time error logging to help you verify performance.
Can I use this kit to run an NTP server?
Absolutely. Once built, you can pair the ESP32 with an Ethernet shield or Wi-Fi and stream the disciplined time to local servers. The firmware skeleton provided in the AI guide includes NTP-compatible timestamp generation.
What happens if the GPS signal drops?
The firmware implements a holdover algorithm that learns the DS3231's drift rate. On signal loss, the RTC free-runs and the OLED shows holdover duration and estimated error, typically staying within 10 �s for up to an hour.
GPS PPS signal disciplines DS3231 RTC to sub-microsecond accuracy. OLED shows sync status and holdover.
What's in this kit
Choose your assembly option:
- Soldering Kit - 25W soldering iron, 60/40 solder wire, flux, and small perfboard for permanent assembly.
- Breadboard Combo - 800-point full-size breadboard with 65-piece jumper wire pack for solderless prototyping.
Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items