Controlling large number of 24VDC lights / switches with Arduino

[wvmarle]

@db44022

I like the concept of the TPIC595, but have a few questions:

1. It looks like they can be used to drive the lights, but they are not able to read switch values?

No, you need a parallel to serial shift register for that, such as the 74hc165. Note that this one can not handle 24V and you need external pull-up or pull-down resistors for your switches.

2 - Should I add any other components between the TPIC595 and the lamps?

It's TPIC6595 (you lost a 6 there). They should be able to control your lamps without extra components.

3 - There is a TPICB595 that seems like a good fit too. Any reason not to use it, as it seems to be more available.

Indeed the TPIC6B595 (again you lost a 6 in the part number) seems to be the most popular one. The key difference is the current they can switch. If your lamps draw less than 150 mA this one will do fine.