Infrastructure-Independent Smart Medication Alert System with GSM-Based Caregiver Escalation and Non-Blocking Acknowledgment

Medication non-adherence is a persistent healthcare
challenge, particularly among elderly individuals and patients
receiving long-term therapy, often resulting in reduced treat-
ment effectiveness and serious health complications. This paper
presents a low-cost standalone Smart Medicine Alert System
based on an Arduino Uno microcontroller. The system integrates
a DS3231 RTC, a 16×4 I2C LCD, a 4×4 keypad, LEDs, an
active buzzer, and a SIM900A GSM module. A non-blocking
timing algorithm based on the millis() function provides a
15-second grace period for user acknowledgment, after which
unacknowledged reminders automatically trigger SMS and voice-
call notifications to predefined contacts. Experimental evaluation
over a continuous 72-hour period demonstrated stable system
operation with an average SMS delivery latency of 4.19 s,
remaining below the 5 s target threshold. The proposed system
provides a simple, affordable, and reliable medication reminder
solution for elderly individuals, patients with chronic diseases,
and caregivers.