NXP Application Code Hub

This demo provides APIs to configure, read and write PCF2131 RTC.

This example provides CMSIS Compliant APIs to configure different operating modes of PCF2131 RTC. It also provides APIs to perform below mentioned operations:

RTC Start
RTC Stop
Get Time
Set Time
Get Recorded Timestamps on Switches
Software Reset
Interrupt Functionality

PCF2131-ARD RTC: Brief Introduction

The PCF2131 is a CMOS real time clock (RTC) and calendar with an integrated temperature compensated crystal (Xtal) oscillator (TCXO) and a 32.768 kHz quartz crystal optimized for very high accuracy and ultra-low power consumption.

PCF2131-ARD RTC: Key Features

Selectable I2C-bus or SPI-bus interfaces for full flexibility when selecting the associated MCU/MPU.
Backup battery input and switch-over circuit, allowing the RTC to keep track of the time, even when the main power supply is removed.
Calendar capabilities to keep tracking of the time from years down to 1/100 seconds.
Up to 4 timestamp registers, which can be associated to timestamp input in order to register tampering events.
Up to 2 interrupt outputs to enable/disable systems to reduce the overall current consumption.
Real Time Clock Block Diagram:

Boards: FRDM-MCXN947 FRDM-MCXA153

Categories: RTC

Peripherals: SPI, I2C

1. Software

IoT Sensing SDK (ISSDK) v1.8 offered as middleware in MCUXpresso SDK for supported platforms
MCUXpresso IDE v11.9.0

2. Hardware

FRDM-MCXN947 MCU board
PCF2131-ARD RTC Device
Personal Computer
Mini/micro C USB cable

3. Setup

3.1 Step 1: Download and Install required Software(s)

Install MCUXpresso IDE 11.9.0 ((https://www.nxp.com/mcuxpresso/ide))
Download and Install MCUXpresso SDK v2.14.0 for FRDM-MCXN947. Make sure to select ISSDK middleware while building SDK.
Install Git v2.39.0 (for cloning and running west commands)

3.2 Step 2: Clone the APP-CODE-HUB/dm-pcf2131-real-time-clock-driver-with-demo-app

Clone this repository to get the example projects:
Change directory to cloned project folder:
cd dm-pcf2131-real-time-clock-driver-with-demo-app

Note: If you are using Windows to clone the project, then please configure filename length limit using below command.

git config --system core.longpaths true

3.3 Step 3: Build example projects

Open MCUXpresso IDE and select a directory to create your workspace.
Install MCXUpresso SDK 2.14.0 for FRDM-MCX947 (drag and drop SDK zip into "Installed SDK" view) into MCUXpresso IDE.
Go to "Quickstart Panel" and click on "Import Project(s) from file system",
Select "Project directory (unpacked)" and browse to the cloned project folder.
Select example projects that you want to open and run.
Right click on project and select build to start building the project.

4. Run Example Projects

Connect the chosen example project HW: FRDM-MCXN947 with PCF2131-ARD.
Right click on project and select "Debug As". Select MCUXpresso IDE LinkServer (inc. CMSIS DAP) probes.
Connect a USB cable between the host PC and the MCU-Link USB port on the target board.
Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.

Note 1: For selecting communication interface, Change:

I2C_ENABLE to 1 under rtc/pcf2131.h for I2C
I2C_ENABLE to 0 under rtc/pcf2131.h for SPI

Note 2: By default SPI/I2C Controller operates in interrupt mode, to switch into EDMA mode Change:

RTE_I2C2_DMA_EN to 1 under board/RTE_Device.h for I2C
RTE_SPI1_DMA_EN to 1 under board/RTE_Device.h for SPI

5. Run PCF2131 Demo Example

User need to check COM port after connecting USB cable between Host PC and Target Board via device manager.

Open PUTTY/Teraterm application installed on your Windows PC with Baudrate 115200 and assigned COM port as mentioned in above step.

After right click on project and select "Debug As", Demo application will run in interactive mode. When the demo runs successfully, you can see the logs printed on the terminal.

LOGS:

Main Menu will look like this

Enter #1 to Start RTC

Enter #4 to Set Time and choose respective sub-options

Enter #5 to Get Time

Enter #5 to Record Timestamps on Switches:

a) Enter sub-option #1 to Enable Timestamp on SW2: 

NOTE: Press SW2 on PCF2131-ARD to enable Timestamp.

b) Enter sub-option #2 Disable Timestamp on SW2:

c) Enter sub-option #3 to Get Timestamp:

Use any option (7,8,9,12) to Enable Interrupts:

a) Steps to Enable Timestamp Interrupt: 

   Timestramp interrrupt is generated on pressing SW1-SW4.

   Below are the steps to Enable timestamp interrupt for SW2:

    Step1: Enter #7 to Enable Timestamp Interrupt

    Step2: Enter #2 to select SW2

    Step3: Choose any one Interrupt Pin and Press Enter

Step4: Press Switch number on which interrupt is enabled to
           get the interrupt

Enter #13 to Clear Interrupt:

6. FAQs

No FAQs have been identified for this project.

7. Support

Provide URLs for help here.

Project Metadata

Questions regarding the content/correctness of this example can be entered as Issues within this GitHub repository.

Warning: For more general technical questions regarding NXP Microcontrollers and the difference in expected funcionality, enter your questions on the NXP Community Forum

8. Release Notes

Version	Description / Update	Date
1.0	Initial release on Application Code Hub	March 28^th 2024
2.0	Additional features for PCF2131 on FRDM-MCXN947 and Complete features for PCF2131 on FRDM-MCXA153	April 30^th 2024
3.0	Fixed Bugs related to EDMA for FRDM-MCXN947 & FRDM-MCXA153	May 30^th 2024

nxp-appcodehub/dm-pcf2131-real-time-clock-driver-with-demo-app