LED drivers for cube

Hello, for my school project, I want to do a 5x5x5 led cube. I have chosen the STP16HC05 drivers for the cube because it can handle current much better than the 74HC595. I was wondering if any 3x3x3 cube project using 74HC595s would work with the STPs just by switching the driver chips and assigning the right wires to the right pins without changing the code? I have tried already using this code:
atomicvpp.com/LED_Cube_Final.pde . It did not seem to work and I do not understand why. Does anybody know what should I have to change to make it work?

Thanks!

It all depends on how you have wired up the cube. Can you post a link to the schematic you used?

I based my circuit on this schematic: http://www.flickr.com/photos/timballas/2054978235/sizes/o/ . The two ICs on the picture are 74HC595s but i used an STP16CP05. The circuit is pretty much exactly the same except for the ICs. I don’t see why the circuit isn’t working.

That is not a schematic, it is a practical wiring diagram and as such is almost impossible to read to get information out of.

Do you have a real schematic, without one you are just blind.

Note that the chip you use will not source current only sink it, that could be the reason why you are having troubles.

The way I wired the MC with the shift registers looks pretty much like this : http://picprojects.org.uk/projects/lc/cube555cS.pdf except that each layer has the cathodes in common and the MC is an ATMEGA1280. From what I understand in the program in my original post, the three pins for each layer flash a LOW signal to light the LEDs while the shift registers send out the HIGH signals.

Grumpy_Mike, what do you mean when you say the chips sink the current? In the datasheet, it says that each output can source 5 to 100mA (http://www.alldatasheet.com/datasheet-pdf/pdf/212721/STMICROELECTRONICS/STP08CP05.html).

it says that each output can source 5 to 100mA

I must admit it is well hidden. The clues are when it says:-

The STP08CP05 guarantees a 20V output driving
capability, allowing users to connect more LEDs in
series

Now you can’t get 20V output from a chip you are driving with 5V but you can drive open drain outputs like this.
Then there is the block diagram on page 4 showing open drain outputs. The equivalent output circuits miss out the output pins altogether. Another clue is the timing diagrams on page 12 only show the output pin states as on and off, not high and low.
The test circuit on page 13 has an arrow going into the chip Iol indicating it is sinking current. Also on the same page the AC characteristics show it being connected to a positive supply (battery).
This chip is much the same as the TPIC6B595 which has a better data sheet.

Look at the application note:-

page 13 talks about constant sink current, and the application circuits are all sink designs.

while the shift registers send out the HIGH signals.

So that explains why it will not work.

Wow that makes a lot of sense now thanks alot. I got the LEDs to light up but no pattern. All the LEDs are ON and wont do anything. Another strange thing is that the GND and VCC pins arent connected to anything and when I connect them to the 5V and GND pins on the Arduino, the LEDs turn off. If I connect the VCC pin to GND on the Arduino, the LEDs become brighter…

This is very intresting, i plan on doing something like this in the near future. i have 20 10mm LEDs, i might have to extend the leads on them because the lights are bigger and the leads are shorter. I’ll examine before i start soldering them. Otherwise i have heals of 5mm that would suit well.

Another strange thing is that the GND and VCC pins arent connected to anything

That is an effect where the power for the chip is bleeding through from the signal lines. The chip won’t work properly, if at all like that but you might see some signals on the outputs. It is not recommended you operate chips like that, you could damage them.

when I connect them to the 5V and GND pins on the Arduino, the LEDs turn off

That’s because the chip is now working properly and as I said that chip only sinks (pull down) current not sourcing it.