The 16 columns of the LED matrix are driven individually by two shift registers (74HC595), whereas the eight combined rows are driven by the decoded outputs from a decade counter (CD4017). In Lab 12, columns were scanned, but here we will be scanning across the rows and feed the column lines with appropriate logic levels. An analog input from a potentiometer is read by the microcontroller to determine the speed of the scrolling message.
- 8x shift registers 74HC595 + 220-pack-8 <---- x le colonne
- 1x decade counter CD4017 + transistor array ULN2803/oppure 8 transistor <---- x le righe
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