/* Input is on pin 3. The program reads 8 bits of data sequentially and stores them as an 8 bit value.
The process of storage is shown using the LEDs. Each bit is shifted to the left. This is a program to
understand the bit-bang process and how the Maxim Integrated 11205 ADC works.*/
/* Include Files */
#include "xparameters.h"
#include "xgpio.h"
#include "xstatus.h"
#include "xil_printf.h"
#include "time.h"
/* Definitions */
#define GPIO_DEVICE_ID XPAR_AXI_GPIO_0_DEVICE_ID /* GPIO device that LEDs are connected to */
#define LED 0xFC /* Initial LED value - XX0000XX */
#define PMOD 0xFC /* Initial LED value - XX0000XX */
#define LED_DELAY 100000000 /* Software delay length */
#define LED_CHANNEL 1 /* GPIO port for LEDs */
#define PMOD_CHANNEL 1 /* GPIO port for PMODs */
#define printf xil_printf /* smaller, optimised printf */
#define PMOD_JA1_DEVICE_ID XPAR_AXI_GPIO_1_DEVICE_ID
#define ABOUT_ONE_SECOND 74067512 //!< approx 1 second delay when used as argument with function delay(numberCyclesToDelay)
// Update this if uBlaze/Zynq CPU core frequency is changed, or if the external memory timing changes.
// Although emprirically tested to 1.0000003 seconds, it is not meant to be used for precise timing purposes
/* Definitions */
#define CLOCK_on 0x08 //high for the clock
#define DATAREADY_high 0x04 //high for data ready pin 3
XGpio Gpio, GpioP; /* GPIO Device driver instance */
u32 LEDOutputExample(void)
{
volatile int Delay;
int Status;
int led = LED; /* Hold current LED value. Initialise to LED definition */
int pmod = PMOD;
int WritetoLEDs;
int i;
u32 x;
u8 uchPortWriteData=0;
u8 uchPortReadData=0;
u32 adcValue=0;
int nClockCount;
int uchUseCalibrationMode=0;
/* GPIO driver initialisation */
Status = XGpio_Initialize(&Gpio, GPIO_DEVICE_ID);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
Status = XGpio_Initialize(&GpioP, PMOD_JA1_DEVICE_ID);
if (Status != XST_SUCCESS) {
return XST_FAILURE;
}
/*Set the direction for the LEDs to output. */
XGpio_SetDataDirection(&Gpio, LED_CHANNEL, 0x00);
/*Set the direction for the PMod - pin 3 is an input, rest are outputs. */
XGpio_SetDataDirection(&GpioP, PMOD_CHANNEL, 0x04);
//WritetoLEDs =0x01;
//for(i =1;i<8;i++){
//XGpio_DiscreteWrite(&Gpio, LED_CHANNEL, WritetoLEDs);
// delay(ABOUT_ONE_SECOND/3);
// WritetoLEDs=(int)(1<<i);
// }
// printf("Ready to receive.\n \r");
//delay(10);
//XGpio_DiscreteWrite(&Gpio, LED_CHANNEL, 0xFF);
// XGpio_DiscreteWrite(&Gpio, LED_CHANNEL, 0x00);
// First, set the clock and data lines low, and the SS# line high
// GPIO[3:0] = {SCK, CLR#, MOSI, SS#} // default 'off' is 4'b0101 = 0x05
//delay(10);
uchPortWriteData = 0;
XGpio_DiscreteWrite(&GpioP, 1, uchPortWriteData); // The (1) means write to the only port (#1) on the uBlaze GPIO port
//delay(10);
// Wait until RDY# goes high
//uchPortReadData = XGpio_DiscreteRead(&GpioP,1);
uchPortReadData=0;
while((uchPortReadData & DATAREADY_high)==0x00) // keep looping while low
{
uchPortReadData = XGpio_DiscreteRead(&GpioP,1);
}
// Now, wait until RDY# goes low
uchPortReadData = XGpio_DiscreteRead(&GpioP,1);
while((uchPortReadData & DATAREADY_high)==DATAREADY_high)
{
uchPortReadData = XGpio_DiscreteRead(&GpioP,1);
}
for(i=15;i>=0;i--)
{
// Send clock high
uchPortWriteData |= CLOCK_on;
XGpio_DiscreteWrite(&GpioP, 1, uchPortWriteData);
// delay(10); // small delay, then read
uchPortReadData = XGpio_DiscreteRead(&GpioP,1);
//delay(10);
// Shift the GPIO read data to the lowest bit, mask off all the other bits, then shift i (15:0)
// number of bits to set the appropriate bit in the
if(((uchPortReadData >> 2) & 0x01)==0x01) // the serial bit is a one, set the bit
{
if(i==15)
adcValue = 0x8000; // extend the sign of the 2s complement number to bits 31..16, and set bit 15 = 1
else
adcValue |= (int)(1 << i); // bit shift
}
uchPortWriteData &= ~CLOCK_on;// Clock in data via negative edge
XGpio_DiscreteWrite(&GpioP, 1, uchPortWriteData);
// delay(10);
// XGpio_DiscreteWrite(&Gpio, LED_CHANNEL, adcValue);
//printf("The Value %d \n \r", adcValue);
//storedValues[i]= adcValue;
}
// The 11205 device requires 25 clocks total to complete a read.
// We have already sent (16) clocks, so send 9 more clocks.
// (If self-calibration mode set then we send 10 more clocks.)
if(uchUseCalibrationMode==1)
nClockCount = 9;
else
nClockCount=9;
for(i=nClockCount;i>=0;i--)
{
// Send clock high
uchPortWriteData |= CLOCK_on;
XGpio_DiscreteWrite(&GpioP, 1, uchPortWriteData);
//delay(10); // small delay, then read
uchPortWriteData &= ~CLOCK_on;// Clock in data via negative edge
XGpio_DiscreteWrite(&GpioP, 1, uchPortWriteData);
//delay(10);
}
//printf("The ADC Value %d \n \r", adcValue);
//XGpio_DiscreteWrite(&Gpio, LED_CHANNEL, 0x01);
// sleep(1);
// XGpio_DiscreteWrite(&Gpio, LED_CHANNEL, 0x00);
//sleep(1);
return adcValue; /* Should be unreachable */
}
void delay(int nStopValue)
/**
* \brief Loop for nStopValue iterations to provide a delay.
* \par Details
* It is commonly used with the constant 'ABOUT_ONE_SECOND' defined in maximPMOD.h for
* setting approximate delays
*
* \param[in] nStopValue - number of iterations to loop
*
* \retval None
*/
{
int i=0;
int a=0;
for(i=0;i<nStopValue;i++)
{
a=i;
}
}
/* Main function. */
int main(void){
u32 storedValues[100]={};
int Status;
int j=0;
while(j<100){
/* Execute the LED output. */
storedValues[j] = LEDOutputExample();
//printf("The J Value %d \n \r", j );
// printf("The STORED Values %d \n \r", storedValues[j]);
j++;
}
int k;
printf("The ARRAY Values \n");
for(k=0; k<100; k++)
{
printf("%d \n \r", storedValues[k]);
}
return 0;
}
