Hi everyone I have a problem in choosing what kind of IC that is possible to expand the pins in Arduino to control multiple relays and my possible option to expand the pins in arduino for the relay that I am thinking is:
Hard to give advice without knowing more about your relays.
Have a look at the TPIC6B595 (ebay).
Shift register, exactly like the 74HC595, but with eight 150mA open drain outputs.
Leo..
EXIA_00:
Because I still don't have any experience in using 595...
Then ask if you don't understand.
Starting a new thread for the same problem isn't going to help.
This page might get you started.
Don't use the 1uF capacitor from the latch pin to ground.
That is a long standing error on this page that nobody seems to be able to correct.
Us a 100n decoupling cap from VCC of the chip to ground if you have one.
Once you understand how to control the LEDs, you can move on to controlling relays.
The only difference is that a TPIC chip is sink only, so the load (LED or relay) goes between output and VCC, not between output and ground.
Relay supply for a TPIC can be a higher voltage, e.g. 12volt for 12volt relays.
Add a diode across the relay coil to kill back-emf.
Leo..