1.7 DMT Timeout

This example application shows how the deadman timer resets by not clearing the deadman timer counter on switch press.

Description

This example application shows how DMT PLIB resets the device by not clearing the deadman timer counter on every user switch press. This application sets up the DMT to reset the device after DMT counter overflows. This application sets up the Core Timer (CoreTimer) to blink an LED and to clear DMT counter before device reset happens. When the user presses the switch, it forces the device to wait an infinite loop to emulate a deadlock condition. As a result, it will triggers the deadman counter overflows the bounded value and device will reset due to this deadman timeout.

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/dmt/dmt_timeout.

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

Project NameDescription
pic32wm_bw1_curiosity.XMPLAB X project for PIC32WM-BW1 Curiosity board

Setting Up the Hardware

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

Project NameBoard
pic32wm_bw1_curiosity.XPIC32WM-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

  1. Open the Terminal application (E.g., Tera term) on the computer.
  2. 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
  3. Build and program the application project using its IDE.
  4. Console displays the following message.
  5. The deadman timer is fed periodically using CoreTimer to prevent the DMT reset and the LED is toggled.
  6. Press the switch to put the system in deadlock (LED should stop blinking).
  7. Below table shows the Switch and LED names:
    BoardSwitch NameLED Name
    PIC32WM-BW1 Curiosity boardSW2Green LED
  8. Console displays the following message.
  9. The DMT will reset the device with in 12 seconds and the demonstration should restart.