lab3

common/reflectance.c

@@ -5,33 +5,105 @@
 #include "inc/msp432p401r.h"
 
 void ReflectanceInit(void) {
-    // write this as part of Lab 3
+    P5->SEL0 &= ~0x08;
+    P5->SEL1 &= ~0x08; // configure P5.3 as GPIO
+    P5->DIR  |=  0x08; // make P5.3 output
+    P5->OUT  &= ~0x08; // set output low
+
+    P9->SEL0 &= ~0x04;
+    P9->SEL1 &= ~0x04; // configure P9.2 as GPIO
+    P9->DIR  |=  0x04; // make P9.2 output
+    P9->OUT  &= ~0x04; // set output low
+
+    P7->SEL0 &= ~0x255;
+    P7->SEL1 &= ~0x255;  // configure P7.0-7 as GPIO
+    P7->DIR  &= ~0x255;  // make them input
+    // P7->REN  |=  0x255;  //? enable pull resistors
 }
 
+// 0 -> while, 1 -> black
 uint8_t ReflectanceRead(uint32_t time) {
-    // write this as part of Lab 3
-    return 0;
+    uint8_t input;
+
+    // 1) Set P5.3 and P9.2 high (turn on IR LED)
+    P5->OUT  |= 0x08;
+    P9->OUT  |= 0x04;
+
+    // 2) Make P7.7 – P7.0 outputs, and set them high (charging 8 capacitors)
+    P7->DIR  |= 0x255;
+    P7->OUT  |= 0x255;
+
+    // 3) Wait 10 us, Delay1us(10);
+    Delay1us(10);
+
+    // 4) Make P7.7 – P7.0 input
+    P7->DIR  &= ~0x255;
+
+    // 5) Wait time us, Delay1us(time);
+    Delay1us(time);
+
+    // 6) Read P7.7 – P7.0 inputs (converts voltages into binary)
+    input = P7->IN;
+
+    // 7) Set P5.3 and P9.2 low (turn off IR LED, saving power)
+    P5->OUT  &= ~0x08;
+    P9->OUT  &= ~0x04;
+
+    //P7->DIR  &= ~0x255;
+    //P7->OUT  &= ~0x255;
+
+    // 8) Return 8-bit binary measured in step 6
+    return input;
 }
 
 int32_t ReflectancePosition(uint8_t sensor_data) {
-    // write this as part of Lab 3
-    return 0;
+    // Data falls into four categories:
+    // 1) <all 0’s> (off the line or on white surface)
+    // 2) <some 0’s, some 1’s>, e.g., 00000111 (off to the left)
+    // 3) <some 0’s, some 1’s, some 0’s>, e.g., 00110000 (over the line)
+    // 4) < some 1’s, some 0’s>, e.g., 11110000 (off to the right)
+    
+    int32_t W[] = {334, 238, 142, 48, -48, -142, -238, -334};
+    // if (!sensor_data) return 0; // off the line or on white surface
+
+    int32_t i, up, down, b;
+    for (up = down = i = 0; i < 8; ++i) {
+        b = (sensor_data & (1 << i)) != 0;
+        up += b * W[i];
+        down += b;
+    }
+
+    return  up / down;
 }
 
 void ReflectanceStart(void) {
-    // write this as part of Lab 3
     // turn on 4 even IR LEDs
     // turn on 4 odd IR LEDs
+    P5->OUT  |= 0x08;
+    P9->OUT  |= 0x04;
+
     // make P7.7-P7.0 out
+    P7->DIR  |= 0x255;
+
     // prime for measurement
+    P7->OUT  |= 0x255;
+
     // wait 10 us
+    Delay1us(10);
+
     // make P7.7-P7.0 in
+    P7->DIR  &= ~0x255;
 }
 
 uint8_t ReflectanceEnd(void) {
-    // write this as part of Lab 3
+    uint8_t input;
     // convert P7.0 input to digital
+    input = P7->IN;
+
     // turn off 4 even IR LEDs
     // turn off 4 odd IR LEDs
-    return 0; // replace this line
+    P5->OUT  &= ~0x08;
+    P9->OUT  &= ~0x04;
+
+    return input;
 }

lab2/main.c

@@ -2,6 +2,23 @@
 #include <stdint.h>
 
 #include "../common/bump.h"
+/*
+#define BUMP_PINS 0b11101101
+
+void BumpInit(void) {
+    // Port 4 pins 0, 2, 3, 5, 6, 7
+    // and enables internal resistors
+    P4->SEL0 &= ~BUMP_PINS;
+    P4->SEL1 &= ~BUMP_PINS; // 1) configure P4.0 P4.2 P4.3 P4.5 P4.6 P4.7 as gpio
+    P4->DIR  &= ~BUMP_PINS; // 2) configure as input
+    P4->REN  |=  BUMP_PINS; // 3) enable pull resisors
+}
+
+uint8_t BumpRead(void) {
+    // write this as part of Lab 2
+    return P4->IN & BUMP_PINS;
+}
+*/
 #include "../common/delay.h"
 #include "../common/clock.h"
 
@@ -52,7 +69,6 @@ void Port2Init(void) {
 int main(void) {
     ClockInit48MHz();
     BumpInit();
-
     Port2Init();
 
     while (true) {

lab3/main.c

@@ -9,17 +9,18 @@
 
 #include "inc/msp432p401r.h"
 
-#define REDLED (*((volatile uint8_t *)(0x42098040)))
-
 #define DUMP_SIZE 256
 
 uint8_t bump_status;
 uint8_t bump_dump[DUMP_SIZE];
+uint8_t refl_dump[DUMP_SIZE];
 
-void DebugDump(uint8_t bump) {
+void DebugDump(uint8_t bump, uint8_t refl) {
     static int idx = 0;
     idx = (idx + 1) % DUMP_SIZE;
+
     bump_dump[idx] = bump;
+    refl_dump[idx] = refl;
 }
 
 // **************SysTick_Init*********************
@@ -38,12 +39,19 @@ void SysTickInit(uint32_t period, uint32_t priority) {
     SysTick->CTRL = 0x00000007;    // 4) enable SysTick with core clock and interrupts
 }
 
+volatile uint8_t reflectance = 0x255;
+int tick_count = 0;
+
 void SysTick_Handler(void) {  // every 1ms
-    // REDLED = 1;
-    // uint8_t bump = BumpRead();
-    // REDLED = 0;
-    volatile int i = 0;
-    ++i;
+    ++tick_count;
+
+    if (1 == (tick_count % 10)) {
+        ReflectanceStart(); // every 10ms
+    }
+
+    if (2 == (tick_count % 10)) {
+        DebugDump( BumpRead(), ReflectanceEnd() );
+    }
 }
 
 int main(void) {
@@ -53,8 +61,5 @@ int main(void) {
     SysTickInit(480000, 1);  // 1ms SysTickInit
     CPU_cpsie();             // Enable interrupts
 
-    while (true) {
-        REDLED = 1;
-        REDLED = 0;
-    }
+    while (true);
 }