It can be done. Whether or not it is practical depends. Here is some code I wrote to run a MAX7219 via a PCF8574. Ignore about 80% of it (related to the MAX7219) and look at the functions with spi in the name.
It can be done. Whether or not it is practical depends. Here is some code I wrote to run a MAX7219 via a PCF8574. Ignore about 80% of it (related to the MAX7219) and look at the functions with spi in the name.