Yeah that makes sense and looking at the datasheet thats what it implied but wanted to check i understood correctly.

Thanks again. I'm starting my first real project, so will almost certainly be asking more questions 

Cheers, thanks guys

A Quick question. Is the voltage of the output pins on a shift register the same and you put in on the Vcc?

Thanks

Thanks for all the help guys. That seems pretty clear now. Going to get this little project out the way then move on to something a little more ambitious.... Rgb led matrix look out!

Thank again.

Hi all. I'm fairly new to the arduino and electronics. I have gone through all the projects that came with the kit and understand it all. However I am now wanting to drive a 7 segment led using a shift register.

One of the projects that came with the kit was driving 8 LEDs with a shift register which I understood as you drove the positive lead of the led high when you want it on. However with the 7 segment led I have, it has the positive as the common to the device (ie all LEDs) and you need connect the LED segments you want to light up to the negative. how can I do this with the shift register? You don't simply drive the pin low do you?

Or can I not use a shift regIster for this?

Many thanks