One year ago, i worked on bit-banging SPI control for three cascaded serial-shift registers. Practically in this example, that is something from which you can control large number of leds like 10×12 = 120 by using just 3 pins (except power supply). In the circuitary for led, i have used high side as well as low side switching which means for multiplexing in coding can mean “0” a high in case of a PNP transistor. Taking that into consideration, i have made a c progarm for logic implementation and then coded that into embedded coding. Here, i am sharing the ino file and logic designing part.
source code can be found on my github repository -> https://github.com/MrityunjaiKumar/MSP430_3shift_register .