Shift registers for switch matrix and LED matrix
I reverse engineered the PCB of a cheap full-size mechanical keyboard so that I can interface it with an ESP32-S3 but I don't have enough GPIOs for both matrices.
The matrices share the column pins.
The switch matrix is wired in 21 columns and 6 rows.
The LED matrix is wired in 22 columns and 6 rows (there is an extra column for the status LEDs) (rows = anode, columns = cathode).
The transistors on the LED matrix are all 2TY for the columns and for the rows (1 = Base, 2 = Emitter, 3 = Collector).
Which type of shift registers do I need for the switch matrix, and which type for the LED matrix? According to this website it seems that I should use the HC164 for the switches and the HC595 for the LEDs, is this correct?
The matrices share the column pins.
The switch matrix is wired in 21 columns and 6 rows.
The LED matrix is wired in 22 columns and 6 rows (there is an extra column for the status LEDs) (rows = anode, columns = cathode).
The transistors on the LED matrix are all 2TY for the columns and for the rows (1 = Base, 2 = Emitter, 3 = Collector).
Which type of shift registers do I need for the switch matrix, and which type for the LED matrix? According to this website it seems that I should use the HC164 for the switches and the HC595 for the LEDs, is this correct?
detailed description of how to use a parallel out shift register to multiplex buttons and switches
