//#define NU32_STANDALONE // uncomment if program is standalone, not bootloaded

#include "NU32.h" // config bits, constants, funcs for startup and UART

#include "LCD.h"

#include <math.h> // math library: sine, sqrt, PI

#define MAX_MESSAGE_LENGTH 200

// Master (c++ code) will be in charge of this program

// - Number of images to grab and fps

// - Pulsetime for droplet generation

// - Delay time after send ExSync but before create droplet

//

// Will receive these from master by serial communication in one string

// Upon receival, slave will set properties and immediately start process

// Once process has finished, will wait for another READUART command from master

// - Serial message: [NUMIMAGES, FPS, PULSETIME, DELAYTIME]

// Synchronization with PPOD controller

//

// CN17 - RF4 - 5V Tolerant

// Exsync Trigger: LOW trigger tells camera to record one frame

//

// CPU running at 40 MHz

//

// LOW: -0.3 V TO 0.8 V {0.0 V}

// HIGH: 2.0 V to 5.5 V {3.3 V}

// Piezoelectric waveform: -Vcc changes to +Vcc for T microseconds, then back to -Vcc

//

// PWMA = 20 kHz PWM - Timer3 - OC1 (D0)

// L1 = Digital Output RA10

// L2 = Digital Output RA2

// VM = 24V / 600mA

//

// CPU running at 40 MHz

//

// FWD-SPD: L1 LOW, L2 HIGH

// BCK-SPD: L1 HIGH, L2 LOW

//

// LOW: -0.3 V TO 1.5 V {0.0 V}

// HIGH: 2.3 V TO 7.0 V {3.3 V}

// ***********************************************************************************************

// Variables to be accessed from multiple functions

// ***********************************************************************************************

// Hold the port F read

unsigned int oldF = 0, newF = 0;

// Create Record flag and turn off

unsigned char RecordFlag = 0;

// Properties set by master

int NUMIMAGES, FPS, PULSETIME;

float DELAYTIME;

// Determine how many frames to delay in order for droplet to contact bath at fixed phase

int DelayFrames = 0;

// Counter for number of PPOD reference signals received since pressed USER button

int RefCounter = 0;

// ***********************************************************************************************

// ISR using Change Notification for synchronization with PPOD controller

// ***********************************************************************************************

void __ISR(_CHANGE_NOTICE_VECTOR, IPL3SOFT) CNISR(void) { // INT step 1

// Since pins on port F are being monitored by CN, must read it to allow continued functioning

newF = PORTF;

// Save the current values for future use

oldF = newF;

// =============================================================================================

// If RecordFlag is on, start the procedure of recording droplet bouncing

// =============================================================================================

if (RecordFlag == 1) {

// -------------------------------------------------------------------------------------------

// Create ExSync Trigger to record one frame per PPOD reference signal

// -------------------------------------------------------------------------------------------

// Initialization of local variables

int counter1, counter2;

int current_frame = 0;

int T1 = (40000000)/(FPS*1.0); // time between triggers - side camera

// Keep track of number of frames

while( current_frame < NUMIMAGES ) {

// -----------------------------------------------------------------------------------------

// Set ExSync signal LOW for 100 clock cycles

// -----------------------------------------------------------------------------------------

// Set A3 to LOW

LATAbits.LATA3 = 0;

// Remain LOW for 100 clock cycles

int counter1 = 0;

while( counter1 < 100 ) {

counter1++;

}

// Set A3 to HIGH

LATAbits.LATA3 = 1;

// -----------------------------------------------------------------------------------------

// Delay W frames for phase relationship of droplet contacting bath before creating droplet

// -----------------------------------------------------------------------------------------

if( current_frame == DelayFrames) {

//+Vcc: set L1 to LOW, L2 to HIGH, PWMA to >0

OC1RS = 4000;

LATAbits.LATA10 = 0;

LATAbits.LATA2 = 1;

//Remain +Vcc for PULSETIME microseconds

int counter3=0;

while(counter3<(PULSETIME*40)) {

counter3++;

}

//-Vcc: set L1 to HIGH, L2 to LOW, PWMA to >0

OC1RS = 4000;

LATAbits.LATA10 = 1;

LATAbits.LATA2 = 0;

// Continue rest of delay until next Trigger

counter2 = 0;

while( counter2 < (T1-100-(PULSETIME*40)) ) {

counter2++;

}

}

// -------------------------------------------------------------------------------------------

// Do nothing

// -------------------------------------------------------------------------------------------

else {

counter2 = 0;

while( counter2 < (T1-100) ) {

counter2++;

}

}

// Increment current frame

current_frame++;

}

// -------------------------------------------------------------------------------------------

// Turn RecordFlag OFF

// -------------------------------------------------------------------------------------------

RecordFlag = 0;

}

// Clear the interrupt flag

IFS1CLR = 1;

}

int main(void) {

// Cache on, min flash wait, interrupts on, LED/button init, UART init

NU32_Startup();

LCD_Setup();

char message[MAX_MESSAGE_LENGTH];

// =============================================================================================

// Change Notification Digital Input Interrupt from PPOD

// =============================================================================================

CNPUEbits.CNPUE17 = 0; // CN17/RF4 input has no internal pull-up

oldF = PORTF; // all pins of port F are inputs, by default

__builtin_disable_interrupts(); // step 1: disable interrupts

CNCONbits.ON = 1; // step 2: configure peripheral: turn on CN

CNENbits.CNEN17 = 1; // listen to CN17/RF4

IPC6bits.CNIP = 3; // step 3: set interrupt priority

IPC6bits.CNIS = 2; // step 4: set interrupt subpriority

IFS1bits.CNIF = 0; // step 5: clear the interrupt flag

IEC1bits.CNIE = 1; // step 6: enable the _CN interrupt

__builtin_enable_interrupts(); // step 7: CPU enabled for mvec interrupts

// =============================================================================================

// PWM and digital output for piezoelectric droplet generator

// =============================================================================================

OC1CONbits.OCTSEL = 1; // Select Timer3 for comparison

T3CONbits.TCKPS = 0; // Timer3 prescaler N=1 (1:1)

PR3 = 3999; // period = (PR3+1) * N * 12.5 ns = 20 kHz

TMR3 = 0; // initial TMR3 count is 0

OC1CONbits.OCM = 0b110; // PWM mode with no fault pin; other OC1CON bits are defaults

OC1RS = 0; // duty cycle = OC1RS/(PR3+1) = 75%

OC1R = 0; // initialize before turning OC1 on; afterward it is read-only

T3CONbits.ON = 1; // turn on Timer3

OC1CONbits.ON = 1; // turn on OC1

// Set A10/A2 to digital output pins

TRISAbits.TRISA10 = 0; // RA10 is an output pin

TRISAbits.TRISA2 = 0; // RA2 is an output pin

//-Vcc: set L1 to HIGH, L2 to LOW, PWMA to >0

OC1RS = 4000;

LATAbits.LATA10 = 1;

LATAbits.LATA2 = 0;

// =============================================================================================

// TrackCam ExSync Trigger

// =============================================================================================

// Set A3 to digital output pin

TRISAbits.TRISA3 = 0; // RA3 is an output pin

//Set A3 to HIGH

LATAbits.LATA3 = 1;

// =============================================================================================

// Keep program running to look for command from master to start record procedure

// =============================================================================================

while(1) {

// Get message from computer

NU32_ReadUART1(message, MAX_MESSAGE_LENGTH);

//Serial message: [NUMIMAGES, FPS, PULSETIME, DELAYTIME]

sscanf(message, "%d%*c %d%*c %d%*c %f", &NUMIMAGES, &FPS, &PULSETIME, &DELAYTIME); //%*c reads in comma and ignores it

// Convert DELAYTIME to DelayFrames

DelayFrames = DELAYTIME*FPS;

// Turn RecordFlag ON since we have received from master

RecordFlag = 1;

// Display properties on LCD

LCD_Clear();

LCD_Move(0,0);

sprintf(message, "%d, %d", NUMIMAGES, FPS);

LCD_WriteString(message);

sprintf(message, "%d, %f", PULSETIME, DELAYTIME);

LCD_Move(1,0);

LCD_WriteString(message);

}

return 0;

}