Efficient LuxMeter Design Using TM4C123 Microcontroller with Motion Detection Application

LuxMeter is widely used to measure light intensity that is required in many medical and agriculture applications. LuxMeter prototypes in the literature have been developed using popular Arduino microcontroller with support from abundant library and programming resources. In this paper, a new prototype of luxmeter system has been designed using ARM Cortex M4 processor based TM4C123 microcontroller, which consumes less power and provides more I/O features compared to Arduino microcontrollers. The details of the hardware and software system design, including I/O interfacing, have been provided to support a wide range of embedded system designs using the TM4C123 microcontroller. The proposed system uses a photoresistor sensor to convert light intensity into a proportional electrical signal and an LCD module to display the final measurement of light intensity via UART interfacing. The microcontroller is programmed in C language to utilize its internal 12-bit analog-to-digital convertor (ADC) module at a sampling rate of 125 KSamples per second. The 12-bit ADC resolution (0–4095) has been normalized to adapt the analog electrical signal level, and the digital output is calibrated as the percent of maximum light illuminance. The system’s functionality in measuring light intensity has been successfully tested and further validated in an experiment of motion detection application.