CCS USB Development Kit SPI Communication

SCSU_Student · Joined: 23 May 2012 Posts: 2

Is there a way to use SPI communication with the CCS USB Development Kit 53314-451? The SDO pin does not have a port, it is only connected directly to the RS232 chip.

ezflyr · Joined: 25 Oct 2010 Posts: 1019 Location: Tewksbury, MA

Hi,

Most of us probably don't have that kit, so we don't know which PIC you are talking about, and we don't have access to the schematic for the board.

It sounds like you are saying that the hardware SPI SDO pin is connected directly to an RS232 level translator IC. If the IC is socketed, you could remove it to free up that line, or you could use a software SPI implementation on another pin.

John

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

SCSU_Student · Joined: 23 May 2012 Posts: 2

I am using SPI to control a DDS chip. I have been using the PIC 18F4455 on a breadboard but it takes up to much space.

The RS232 IC is not socketed. What I was thinking about doing is removing the RS232 IC because I do not need RS232 communication, then soldering a lead across from the SDO trace to where it goes into the RS232 connector on the board. I would then just plug in a cable to the RS232 connector. Here is a link to the board layout: http://www.ccsinfo.com/pdfs/product_PDFs/USB_board.pdf

Would that work or would there be a better way to do it.

The pin used as SDO for the 18F4550 is C7.

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Do you need to use hardware SPI ? Do you need the speed ?
If not, you can use software SPI. For that, you can either write
your own "bit bang" code, or you can use the #use spi() library
provided with the CCS compiler.

Post the manufacturer and part number of the DDS chip.