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.
Thanks in advance!
EDIT: or should I use a ULN2803 ??
It's just like your 74HC595 but it has eight current controlled inputs.
It does not seem to be in the catalog of my current vendor. Are there any other alternatives?
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.
Who's your current vendor?
It seems the ULN2803 needs 8 pins to be controlled, is that right? It's a bit extreme.
I can't find the other ships on http://www.reichelt.de/
EDIT: I found the TPIC6B595, thank you. (it's TPIC not TCIP)