spi.cpp

00001 /******************************************************************************
00002 * EECS 397
00003 *
00004 * Assignment Name: Lab 6: WaG
00005 * 
00006 * Authors: Sam Morrison and Phong Nguyen 
00007 * File name: spi.cpp
00008 * Purpose: Driver for SPI functions
00009 *
00010 * Created: 03/01/2018
00011 * Last Modified: 03/29/2018
00012 *
00013 ******************************************************************************/
00014 
00015 #include "mbed.h"
00016 #include "io_pins.h"
00017 #include "spi.h"
00018 #include <stdlib.h>
00019 #include <stdio.h>
00020 #include <string.h>
00021 
00022 extern SPI wag_spi;
00023 
00024 DigitalOut dsp_ncs(DSP_AS1107_NCS);//This sets up the chip select for the AS1107
00025 
00026 
00027 extern struct spi_cfg as1107;
00028 
00029 
00030 /*
00031  * void spi_send(struct spi_cfg spi_config, int spi_data);
00032  * Description: sends an instruction to an SPI device
00033  *
00034  * Inputs: 
00035  *      Parameters:
00036  *          struct spi_cfg spi_config: structure containing device qualities
00037             int spi_data: command to write to device
00038  *      Globals:
00039  *      
00040  * Outputs:
00041  *      Returns: void
00042 */
00043 void spi_send(struct spi_cfg spi_config, int spi_data) {
00044     static int previous_id = SPI_NO_ID;
00045     spi_config.spi_ncs = 1;
00046     if (previous_id != spi_config.spi_id) {
00047         //send config data to master
00048         previous_id = spi_config.spi_id;
00049         wag_spi.frequency(spi_config.spi_freq);
00050         wag_spi.format(spi_config.spi_no_bits, 0);
00051     }
00052     spi_config.spi_ncs = 0;
00053     wag_spi.write(spi_data);
00054     spi_config.spi_ncs = 1;
00055 }
00056