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  • Author Author: bose
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PSoC4 Smarter Life Challenge - DAS Project: LCD Update

bose

The Nokia LCD in now working with the PSoC4 Pioneer Kit using the UDB based SPI interface.

There was a slight change needed to help interface the SDcard also to this interface.

Here is what it came to finally:

image

The additional 'OR' with the control helps to disable the SS line of the LCD.

By setting the SS_Reg [Control_0] to 1 the OR gate would keep the SS pin of the LCD high permanently, even when the internal UDB SPI pin toggles.

Only when this bit in the SS_Reg is made low the toggles from UDB SPI go to the SS pin of the LCD.

 

Now why to use a 'OR' gate instead of directly controlling the SS line of LCD.

The requirement from the SS pin of the LCD states that for each byte transfer we need to have the SS line toggle.

This can easily be done in the software using a control register.

However if we have this 'OR' gate we need not control the SS pin in software , the same would directly be activated by the UDB SPI when byte transfers occur.

This reduces the code size.

In case of SD card the software control of the SS line is still possible using the same register by disabling the LCD SS.

Here are configuration snapshots:

image

imageimage

Presently the Fonts are working on the LCD, and the updates are very fast.

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