interfacing pmod cls with zybo

[Pujith Krishna]

not able to get the output of pmod cls with the demo code provided while i am interfaing with zybo board via i2c 

[JColvin]

Hi @Pujith Krishna,

What revision of the Pmod CLS do you have? It looks like your jumpers on the Pmod CLS are not set up for SPI communication. If you have a Rev E of the Pmod CLS, please put a shorting block on both pins of MD0 and leave the other pins unconnected. If you have a different revision, please put a shorting block on both pins of MD2 and MD1 and leave MD0 unconnected.

Let me know if this works.

Thank you,
JColvin

[Pujith Krishna]

Hii...i have the pmod cls of rev E

I tried shorting the md0 and left the remaining pins...and leaving the md0 shorting the remaining pins but still it is not working.

And let me know how to increase the backlight .

[JColvin]

Hi @Pujith Krishna,

I looked again at your post and noticed you are looking to use I2C on the Pmod CLS with the Zybo. Unfortunately our IP core for the Pmod CLS, as reflected in your block design, is designed to work with SPI. The I2C mode is currently not implemented in the IP core. If you wanted to use SPI, you would also need to move the Zybo over one port so that header J1 is in the top row of Pmod Host port JC on the Zybo.

In terms of the backlight, the function is not currently built into the demo, but the short answer is that following function would need to be added to the end of DemoInitialize() function in the main.c

uint8_t setupString[] = {CLS_ESC, CLS_BRACKET, '3', DISP_EN_CMD}
CLS_WriteSpi(&myDevice, setupString, 4);

Let me know if you have any questions.

Thanks,
JColvin

[Pujith Krishna]

yah....the spi is working fine but backlight is not switching on

[JColvin]

Hi @Pujith Krishna,

I realized that I had provided you with slightly incorrect code, the first line should instead be

uint8_t setupString[] = {CLS_ESC, CLS_BRACKET, '3', CLS_DISP_EN_CMD};

but when I tested this for myself on the Zybo, I was unable to get the backlight to turn on. I was also unable to get the library for a microcontroller to turn on the backlight as well. I will look into this further, but comparing between the schematic and board itself, I'm not certain if the backlight can be turned on.

I'll let you know what I find out.

Thanks,
JColvin