---
title: "P2 RTC Add-on with GPS Module"
description: "[Quick Byte: GPS and Real-Time Clock](https://www.youtube.com/embed/jnSHeGuFUxQ?feature=oembed) ##### Description This Quick Byte shows how to use a GPS module to accurately set the date & time in your RTC (Real Time Clock) module. The example code includes SPIN2 code drivers for…"
url: "https://obex.parallax.com/docs/quick-bytes/propeller-2/p2-rtc-add-on-with-gps-module/"
updated: "2026-09-29"
category: Propeller 2
---

# P2 RTC Add-on with GPS Module

[Quick Byte: GPS and Real-Time Clock](https://www.youtube.com/embed/jnSHeGuFUxQ?feature=oembed)

##### Description

This Quick Byte shows how to use a GPS module to accurately set the date & time in your RTC (Real Time Clock) module. The example code includes SPIN2 code drivers for both the RTC and GPS modules.

Adding a source of accurate time is important for many projects, and combining the GPS module with your RTC can be a really convenient and autonomous way to ensure the time is right.

Examples in real world applications include battery-powered (or low power) systems, where having the GPS running constantly as a time reference would consume more power compared to the very low power requirements of the RTC module. In these cases, having the GPS power up once a week (for example) to update the RTC time could provide a significant power saving. Another example would be for systems that do not always have GPS coverage, and in such applications the RTC would keep time whilst the GPS is out-of-range.

For help please feel free to ask your questions here, or for a wider audience of helpers at our [https://forums.parallax.com](https://forums.parallax.com/).

##### Hardware Connections

Follow the video above or these pictures to wire up the hardware listed under Parts Used (below).

![Collection of hardware needed for this Quick Byte, as listed in Parts Used](/qbi/P2 RTC Add-on With GPS Module - Parallax_files/GPSDemo_Hardware_1.jpg)![Plug in the Prop Plug and power plug to the P2 Edge Mini Breakout Board](/qbi/P2 RTC Add-on With GPS Module - Parallax_files/GPSDemo_Hardware_2.jpg)![Connect the GPS module to the Breakout Board with jumper wires](/qbi/P2 RTC Add-on With GPS Module - Parallax_files/GPSDemo_Hardware_3.jpg)![Assembled GPS P2 Quick Byte project](/qbi/P2 RTC Add-on With GPS Module - Parallax_files/GPSDemo_Hardware_4.jpg)

##### Parts Used

- [P2 RTC Add-on Board](https://www.parallax.com/product/p2-rtc-add-on-board/)
- [SIM33EAU GPS Module](https://www.parallax.com/product/sim33eau-gps-module/)
- [200mm Jumper Wires, FF 40-piece Ribbon](https://www.parallax.com/product/200mm-jumper-wires-ff-40-piece-ribbon/)
- [P2 Edge Module](https://www.parallax.com/product/p2-edge-module/)
- [P2 Edge Mini Breakout Board](https://www.parallax.com/product/p2-edge-mini-breakout-board/)
- [USB Mains Adapter, 18W, 5V, 3A](https://www.parallax.com/product/usb-mains-adapter-18w-5v-3a/)
- [USB A to DC 2.1mm Jack Cable](https://www.parallax.com/product/usb-a-to-dc-2-1mm-jack-cable/)
- [Prop Plug Rev E](https://www.parallax.com/product/prop-plug/)
- [USB A to Micro B Cable](https://www.parallax.com/product/usb-a-to-micro-b-cable/)

##### Source Code

- [P2 RTC Add-on with GPS Module Example Code](/qbi/downloads/64013_RTC_Example_with_GPS-Archive-Date-2022.12.20-Time-14.10.zip)

##### Programming Language

- [Spin 2](https://docs.google.com/document/d/16qVkmA6Co5fUNKJHF6pBfGfDupuRwDtf-wyieh_fbqw/)
- [PASM2](https://docs.google.com/spreadsheets/d/1_vJk-Ad569UMwgXTKTdfJkHYHpc1rZwxB-DcIiAZNdk/)

##### Tools and Operating System

- [Propeller Tool for Windows](https://www.parallax.com/package/propeller-tool-software-for-windows-spin-assembly-2/)
- [FlexProp for Windows, Mac and Linux](https://www.patreon.com/totalspectrum)

##### Additional Resources

- [Propeller 2 Spin Documentation](https://docs.google.com/document/d/16qVkmA6Co5fUNKJHF6pBfGfDupuRwDtf-wyieh_fbqw/edit)

[Propeller 2 Live Forum Video: Simple Analog Input](https://youtu.be/K-pGbQD_biE?si=PqNuDQVDS_doBlvM)

##### Document Author

- Michael Mulholland

##### Source Code Author

- Michael Mulholland