⚠️ The Problem :

In low-voltage embedded systems, microcontrollers may hang or freeze due to glitches, brown-outs, or noisy power lines—especially in battery-operated or IoT devices. Without a watchdog circuit, your system may stop functioning until manually reset, which is impractical in remote or critical applications.

✅ The Solution :

A watchdog timer (WDT) circuit monitors system activity. If the microcontroller doesn’t “check in” regularly, the watchdog resets it—keeping your system reliable. For low-voltage systems (like 3.3V or 1.8V), it’s crucial to use ultra-low power watchdog ICs or build a simple watchdog using a MOSFET and RC timing.

🔍 Practical Example :

Say you’re developing a soil sensor node powered by a 3.7V Li-ion cell. Occasionally, due to low battery, the microcontroller hangs. Adding a watchdog timer ensures automatic resets, avoiding total communication loss.

🧮 Sample Calculation :

To build a basic watchdog delay, use:

T=R×C

For R = 100kΩ and C = 10µF:

T=100,000×0.00001=1 second

If the MCU doesn’t toggle the watchdog within 1 second, it resets the system using a MOSFET.

🛒 Product Suggestion – Made in India :

Build robust watchdog circuits using low Rds(on) MOSFETs and timing capacitors, proudly made in India:

🔧 Buy Power MOSFET

🔧 Get Electrolytic Capacitor

✅ Shop now at SmartXProKits.in
Support our work and India’s innovation—buy from our Make in India site!