EM11 · Sem 6 · Embedded systems

LCD stopwatch with millis()

Aim: Show elapsed time on an LCD using millis().

🧪 Live simulation🧊 Real-time 3D bench⚠ Simulated values, not physical measurements

🔬 Virtual lab

Starting the lab…

millis() returns time since start. Dividing into minutes, seconds and tenths and formatting with snprintf gives a stopwatch without blocking.

s = millis()/1000, tenths = (millis()/100) % 10

Observations and result (kept on this device)

Why not use delay() to keep time

Code between delays adds error; millis() is the true elapsed time.

What happens when millis() overflows

It wraps after about 49 days; subtract timestamps to stay correct.

Virtual board. On real hardware, check supply voltages and pin current limits, and power motors and servos from a separate supply.