Three approaches to light an 8×8 LED dot-matrix display

This paper investigates three display approaches, called row-scan, column-scan, and dot-by-dot, to light character patterns on the 8×8 LED dot-matrix display and examines the cause of the different display outcome. Three field programmable gate array (FPGA) based circuit versions were designed to implement the investigation. The current flow through each lit LED of the lower-case character r matrix was measured for luminous intensity comparison. The trend of the brightness inhomogeneity among lit LEDs was identified. The result suggests valuable information for circuit designers to choose an adequate display technique.