hc-8+ and ws2801 LED strips question

[sssidney]

Hi,

I'm starting my burningman project for next year. You can never start too soon!

I'm planning on running as many ws2801 led strips as I can though a hc-8+ board (and the microSD adapter). I'm a bit hardware challenged so I have some  questions related to power.  The ws2801 led strips are powered with 5v. Can I power the entire project (hc-8+ and leds) through the boards high-current power input with a 5 Volt Power Supply (60A, 300) like this one http://www.mpja.com/mobile/5-Volt-Power-Supply-60A-300W-Switching-Hengfu/productinfo/16486%20PS/. In the HC-8+ manual it says the hc-8+ board is powered from 9 to 24 volts DC. Does that mean I can't run the entire board with my 5v power supply?

Does it matter if I use the TTL output headers or the high-current, high-side outputs to the led strips?

How many leds can I run per hc-8+ output port?


Thanks,
Dave

[JonnyMac]

You must supply the HC-8+ with more than 5v. I would suggest a small 12, 500mA supply -- that will be enough to run the digital circuitry. Connect ground from your external supply to ground on the HC-8+. That way you can take 5v signals to the strip from the TTL header.

Have a look at this video:
-- http://www.youtube.com/watch?v=YuSMKciw0J8

That prop (for Steve Wang's shop) has an HC-8+ embedded in the "spell globe" which is running a WS2801 light strip (about 95 pixels) on the strip. I've attached the latest version of my WS2801 driver -- it's pretty easy to use.

[sssidney]

Your article about the spell globe project in Nuts and Volts is what motivated me to buy an HC-8+ for my  project.

Sorry I'm still confused – I need 2 power supplies – a small 12v supply to run the board  and a 5v supply for the leds.
The 5v supply will have ground connected to the HC-8+ ground and the positive side connects to what?

How do these connections relate to the diagram of the board on page 2 of the documentation?

Do I need to  follow note 2 on that same page?
"2. Before use, internal 5v supply to TTL header must be severed (see bottom of PCB for cut point)"

[JonnyMac]

For safety and so that you don't have to modify the HC-8+, we suggest you use a small wall-wart to power the board. The only connection between the external supply and the HC-8+ is ground. You will run the signal (white) wires from the header to the strip. Power and ground from the strip will come from the external power supply.

Do not connect the 5v supply and the 5v system of the HC-8+.

[sssidney]

Did part of this sentence from your reply get cut off? "Power and ground from the strip will"

[JonnyMac]

Whoops... fixed that sentence and added a connection diagram.

[sssidney]

Thanks for your help! It's greatly appreciated. I'm sure I'll have more noob questions.