OMAP-L138, SPI and serial ADC

Hi,

I am doing the same thing with you. I want to know whether your problem have solved? And how to ?

I am working with OMAP-L138, and I also trying to connect serial ADC to the SPI1 of OMAP-L138. My problem is I cannot get SPI1_CLK although I set spi_config.freq = 500000.

If you have successed in using SPI, can you give me some examples for reference?

Thanks

lex

Yes,

I have successfully connected ADC to the SPI. I did not use any CSL or similar packages but configured the SPI directly through registers and used DMA to read the data from ADC. Actually I had to use two DMA channels, one channel that writes dummy data to the SPI in order to initiate the transaction and the second one which is actually reading data from the SPI (from ADC). One big problem that I have faced with SPI use as interface to ADC is the fact that SPI module does not have FIFO, so high peak load on the OMAP bus caused sample rate changes, I have moved to McBSP bus for this reason.

Alexey.

Hi,

I also configured SPI directly through registers, I referred to evmomapl138_spi.c to configure SPI1. After the configuration of SPI1, I cannot get SPI1_CLK.

How to solve the problem?

Can you share your demo about SPI  for reference?

Thanks!

lex

Dear Alexey

I am working on beam former for vehicle collision avoidance. I need your help in interfacing Serial ADC to SPI channel. I need atleast 8 channels of above 10 bit resolution.

Hemant

Hi,

I have noticed that SPI bus of OMAP-L138 is not good for maintaining constant sample rate for ADC or DAC as it does not have internal FIFO. I would suggest you to use McBSP instead of SPI....

Dear Alexey,

I need 8 audio analog input and I am working for first time with DSPs...tried McBSP for the existing audio input and its working...if its ok with you..can you share your design document for integrating additional ADC through McBSP...it will be great help to me..

hemant

I have olny connected one channel ADC to McBSP, so I am not sure I can help you with 8 channels.

Alexey.

hi,

the channel you connected is in addition to the existing channels...

hemant

Hi!

I'm also trying to connect an ADC using an SPI interface, but I'm having lots of problems. I tried to follow one of the examples using a GIO interface to control the SPI, but when I do the GIO_read, the data that comes in through the SOMI channel is not what it's supposed to be, can anyone help me understand a little more how to make this communication work.

Thanks in advance,

- Aquiles Lacruz