USB Watchdog for Automatic PC Restart - Reset Master

Overview

The TDPC0201 "Reset Master" is a USB watchdog that resets the PC's motherboard if its timer is not cleared within 210 seconds. Sending a clear command resets the timer to zero and starts a new 210-second interval. To keep the PC running, send this command regularly before the interval expires.

If the PC or operating system freezes and the commands stop, the TDPC0201 resets the motherboard. This provides a hardware reset even when a normal software restart is no longer possible.

The warning buzzer sounds 180 seconds after the last timer-clear command, followed by a reset 30 seconds later. Both timing intervals are configurable.

Typical Applications

• Digital signage
• Remote IoT devices
• Mining rigs

Connections

1. Refer to the connection diagram above and connect the TDPC0201 output pins to the motherboard's reset-switch header. Observe the + and - polarity. To retain a manual reset button, connect it to the additional pair of pins shown in the diagram.

2. Connect the TDPC0201 to the PC using the USB cable.

3. Start the PC.

4. Keep clearing the watchdog timer with the control command to prevent the TDPC0201 from resetting the PC.

Control Commands

Use the TD-USB command-line utility to control the device.

Run the following command from a Windows or Linux command line to clear the TDPC0201's internal watchdog timer. Run it repeatedly at intervals shorter than the configured reset timeout.

td-usb tdpc0201 set

You can also change the device settings. The following example sets a 300-second delay before the warning buzzer sounds, followed by a 10-second delay before the motherboard is reset:

td-usb tdpc0201 set WATCHING_TIME=300
td-usb tdpc0201 set WARNING_TIME=10

After changing the settings, save them to the device's nonvolatile memory. Without save, the device returns to its previously saved settings after a power cycle:

td-usb tdpc0201 save

System Requirements

• An AT-compatible PC motherboard with a two-pin reset-switch header
• A USB port
• Windows 7 or later, or Linux