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@article{206250,
        author = {Vrushabh Manoj Ukhalkar},
        title = {Custom-Driver-Based UART Bluetooth Home Automation System Using LPC2138 ARM7 Microcontroller with LCD Feedback and Response-Latency Evaluation},
        journal = {International Journal of Innovative Research in Technology},
        year = {2026},
        volume = {13},
        number = {2},
        pages = {746-751},
        issn = {2349-6002},
        url = {https://ijirt.org/article?manuscript=206250},
        abstract = {Bluetooth-based home automation provides a simple and low-cost method for short-range wireless control of electrical loads. This paper presents the design and implementation of a custom-driver-based UART Bluetooth home automation system using the LPC2138 ARM7TDMI-S microcontroller, HC-05 Bluetooth module, onboard LED load indicators, manual switches, and a 16×2 LCD display. The proposed system receives ASCII commands from an Android Bluetooth terminal application through the HC-05 Bluetooth module. The received Bluetooth data are converted into UART serial data and processed by the LPC2138 through UART1. Based on the decoded command, the firmware updates GPIO outputs and displays real-time load status on the LCD. Unlike library-dependent platforms, the system is implemented using bare-metal Embedded C with custom UART, GPIO, switch, command-decoder, output-manager, and 4-bit LCD drivers. The firmware also handles invalid commands and filters carriage-return and newline characters transmitted by mobile Bluetooth terminal applications. Prototype-level testing was performed for functional operation, response delay, command reliability, and operating distance. The average command response delay was approximately 56 ms, while command reliability was observed between 95% and 100% during repeated trials. The work demonstrates a compact, low-cost, educational, and reproducible ARM7-based Bluetooth automation prototype with UART protocol justification, LCD feedback, manual override, and response-latency evaluation.},
        keywords = {Bluetooth communication, Embedded C, HC-05, home automation, LCD interfacing, LPC2138, UART.},
        month = {July},
        }