Allegro A6280 with PICBASIC

[zebulontan]

Hello,

I don't understand the principle of the shift register of the A6280. I need to control 20 RGB pixels separately. Is this principle work ? :

1) Load RGB data of pixel 1
2) Load RGB data of pixel 2
..) ...
20) Load RGB data of pixel 20
21) Latch
22) Load RGB data of pixel 1
....

Thank tou for your help

[Darrel Taylor]

If pixel 1 is the LAST one in the string, then yes.
Send the data for all pixels then latch it. All pixels update at the same time.

[zebulontan]

ok, thank you for this fast reply,
A6280 is perfect for my application : (low resolution screen).

I'm going to test it soon

[Photovor]

I know I'm coming in on this thread a little late, but I'm trying to control the A6280 as well. I'm using a PIC16F873a which has a SPI port. Supposedly it is very easy to use the SPI port because it handles the serial clocking of the data and such. I was wondering if someone could clarify something though. Does the SCK pin maintain a constant clock pulse. I believe how it's setup is to deliver OSC/4 to that.

[Darrel Taylor]

Does the SCK pin maintain a constant clock pulse.

It Does NOT.

It only puts out a CLK when data is being sent.
The A6280 needs a CLK all the time though, not just when there's data.

[Photovor]

Thanks for the clarification. Is there a way to utilize the oscillator that is supplying the clock for the PIC to also supply the clock pulse for the A6280, and use the SPI functions as well? Or would SPI not work at all in this example? It's a shame that the A26281 just comes in a QFN package, considering it has its own internal PWM counter.

[Darrel Taylor]

... Is there a way to utilize the oscillator that is supplying the clock for the PIC to also supply the clock pulse for the A6280, and use the SPI functions as well? ...

It's possible, with external hardware, extra pins on the chip, and a great deal of thoughtful programming.

But since you can use the CCP module in co-operation with SHIFTOUT commands on 2-3 PINs and no external hardware .... Why?