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Topic: TLC5940 - using ATTINY85 to control GSCLK and BLANK (Read 608 times) previous topic - next topic

AllanB

Dec 10, 2013, 01:46 pm Last Edit: Dec 10, 2013, 01:50 pm by AllanB Reason: 1
Hi there

I'm using TLC5940 to control LED's and Servos. I made the GSCLK signal by a 555-circuit to reduce the use of Arduino pins. But it is not precise and I also would like to reduce the number of discrete components. I have a bunch of ATTINY85 lying around.

My idea is to make ATTINY85 control GSCLK and BLANK. Not connected to the Arduino but just contantly providing GSCLK and BLANK signals.
Arduine should then program TLC5940 by using XLAT, SIN and SCLK.
My question is. Are there any dependencies between XLAT on one hand and GSCLK and BLANK on the other? In other words, should the timing of the lathing take into account how far the counter of GSCLK is in its sequence?
Is it a possible solution?

Thanks

fungus

It won't work.

In the "Serial Interface" section of the datasheet it says:
Quote

"the XLAT signal should only latch the grayscale data at the end of the grayscale cycle. Latching in new grayscale data immediately overwrites the existing grayscale data".

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

AllanB

I see Fungus. I missed that part. Thanks.

Well - then I could use the extra free pins on ATTINY85. So the latch goes from Arduino to ATTINY85 and from there to TLC5940 when ATTINY85 is at the end of the grayscale cycle.

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