I have a 8x8 LED Matrix. I control the output with a 74HC595 chip, this basically controls the line for the display (given a particular column it controls which LED will be displayed). In this configuration 1 of 8 pins get connected to +5V. This works.
Now I need to controller the column and it depends on which pin is connected to the GND. In this configuration 1 of 8 pins get connected to 0V. This need to be done.
What inexpensive chip exist to do that?
Searching on the forum I saw the PCF8574 but it's not clear to me if it's right and the simplest inexpensive solution for me.
ULN2803, one output low at a time. Buffer arduino outputs with it, or outputs of 74CH595.
Even better, use a TCIP6B595 open drain shift register with high current sinking capability.