1.4 ADC Window Sleepwalking

This application shows how to configure ADC in a sleepwalking operation, where input voltage is measured at a fixed interval, but device is not woken from sleep until the measured value is below a given threshold.

Description

This example application shows how to use the ADC Peripheral library to perform sleepwalking. The ADC peripheral is configured to operate in window mode. The ADC conversion is triggered by RTC compare 0 event. On every trigger, window detection operation is performed in standby sleep. The window interrupt is generated when the input voltage falls below the window upper threshold and the CPU is woken up by this interrupt. ADC window upper threshold is configured as 1/4 th of the reference voltage.
BoardADC Window Upper Threshold
PIC32CM LE00 Curiosity Pro0.825V

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. This content can also be downloaded using content manager by following these instructions.

Path of the application within the repository is apps/adc/adc_window_sleepwalking/firmware.

To build the application, refer to the following table and open the project using its IDE.

Project NameDescription
pic32cm_le00_curiosity_pro.XMPLABX project for PIC32CM LE00 Curiosity Pro Evaluation Kit

Setting Up the Hardware

The following table shows the target hardware for the application projects.

Project NameBoard
pic32cm_le00_curiosity_pro.XPIC32CM LE00 Curiosity Pro Evaluation Kit

Setting Up PIC32CM LE00 Curiosity Pro Evaluation Kit

  • Connect the Debug USB port on the board to the computer using a micro USB cable

Running the Application

  1. Open the Terminal application (Ex.:Tera term) on the computer
  2. Connect to the EDBG Virtual COM port and configure the serial settings as follows:
    • Baud : 115200
    • Data : 8 Bits
    • Parity : None
    • Stop : 1 Bit
    • Flow Control : None
  3. Build and Program the application using its IDE
  4. Vary the on-board potentiometer to change the ADC input voltage
  5. Console displays ADC Window Detected when ADC input is lower than 1/4 th of the reference voltage (i.e below 0.825V):