1.11 FREQM Measurement
This example application demonstrates how to use the FREQM peripheral to measure the frequency of the internal RC Oscillator.
Description
The FREQM can be used to accurately measure the frequency of a clock by comparing it to a known reference clock. The FREQM counts the number of periods of the measured clock with respect to the reference clock. This example application shows how to measure the CPU frequency using the 32-kHz crystal oscillator as the reference clock.
Downloading and Building the Application
To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file.
Path of the application within the repository is apps/freqm/freqm_measure_clock_freq.
To build the application, refer to the following table and open the project using its IDE.
| Project Name | Description |
|---|---|
|
pic32wm_bw1_curiosity.X | MPLAB X project for PIC32WM-BW1 Curiosity board |
Setting Up the Hardware
The following table shows the target hardware for the application projects.
| Project Name | Board |
|---|---|
| pic32wm_bw1_curiosity.X | PIC32WM-BW1 Curiosity board |
Setting Up PIC32WM-BW1 Curiosity Board
- Connect the USB port on the board to the computer using a USB Type-C cable
Running the Application
- Open the Terminal application (E.g., Tera term) on the computer.
- Connect to the USB COM port and
configure the serial settings as follows:
- Baud : 115200
- Data : 8 Bits
- Parity : None
- Stop : 1 Bit
- Flow Control : None
- Build and program the application using its IDE.
- Observe output message in console
as follows.
Note: The measured clock frequency is approximate. The actual frequency may vary due to the measurement error.