Diff: IMD/IMD.cpp

Revision:

30:91af74a299e1

Parent:

24:f58a3c0071c3

Child:

31:7eaa5e881b56

--- a/IMD/IMD.cpp	Fri Nov 07 21:26:46 2014 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,126 +0,0 @@
-#include "IMD.h"
-#include <math.h>
-
-static IMD* instance;
-
-const uint32_t PCLK = 24000000;     // Timer counting clock = 24Mhz
-const uint32_t TIMEOUT_TICKS = PCLK*ZERO_HZ_TIMEOUT;    // Zeroing timeout in clock ticks = seconds * PCLK
-const float EXTRA = 0.01;           // Margin on the IMD PWM limits
-
-// Interrupt function, must be static context
-void tim0_IRQ() {
-    // Capture event was found
-    if (LPC_TIM0->IR & 1<<4) instance->edgeIRQ();
-    
-    // MR0 (zero Hz timeout) event was found
-    if (LPC_TIM0->IR & 1) instance->zeroIRQ();
-    LPC_TIM0->IR=0x3F;        // Clear interrupt flags
-}
-
-IMD::IMD() {
-    instance = this;
-    first = true;
-    startTime = 0;
-    widthTicks = 0;                 // Zero low, so that duty = 0/1 = 0%
-    periodTicks = 1;
-    
-    LPC_SC->PCONP |= (1<<1);        // Power on timer0
-    LPC_SC->PCLKSEL0 &= ~(3<<2);    // Clock at 24MHz
-    
-    *(p1_26.pinsel_addr)  |= 3 << p1_26.selmode_num;     // Set pin as capture pin
-    *(p1_26.pinmode_addr) |= 3 << p1_26.selmode_num;     // Pull down
-    
-    LPC_TIM0->TCR=2;       // Stop counter and hold at 0, for configuration, set to 1 to start operation
-    LPC_TIM0->IR=0x3F;     // Clear any interrupt flags
-    LPC_TIM0->CTCR=0;      // Use pclk, not external pin
-    LPC_TIM0->PR=0;        // No prescale value, clock at full pclk=24Mhz
-    LPC_TIM0->EMR=0;       // Do not use external match pins
-    
-    NVIC_SetVector(TIMER0_IRQn, (uint32_t)&tim0_IRQ);   // Point to the interrupt handler
-    NVIC_SetPriority(TIMER0_IRQn, 0);                   // Highest Priority
-    NVIC_EnableIRQ(TIMER0_IRQn);                        // Enable IRQ
-    LPC_TIM0->CCR = RISING;          // Generate interrupt on capture, capture on rising edge to start
-    LPC_TIM0->MCR = 1;               // Interrupt on Match0 to establish the zero speed timeout
-    LPC_TIM0->MR0 = LPC_TIM0->TC+TIMEOUT_TICKS;
-    LPC_TIM0->TCR = 1;               // Start counting, GO!
-}
-
-void IMD::edgeIRQ() {
-    uint32_t type = LPC_TIM0->CCR;
-    uint32_t capTime = LPC_TIM0->CR0;
-    LPC_TIM0->MR0 = capTime+TIMEOUT_TICKS;        // Set the next zeroing timeout
-    
-    // Special case - on first pulse after a timeout or on startup, period cannot be calculated
-    //    so set startTime such that periodTicks remains unchanged from its zero state (periodTicks=1)
-    if (first) {
-        first = false;
-        startTime = capTime - 1;   
-    }
-        if (type == RISING) {
-        periodTicks = capTime - startTime;  // Get the period on Rising edge
-        startTime = capTime;                // Set the start of the next pulse
-    }
-    if (type == FALLING) {
-        widthTicks = capTime - startTime;   // Get the pulse width on Falling edge   
-    }
-    
-    // Switch interrupt types to capture the next edge
-    if (type == RISING)  LPC_TIM0->CCR = FALLING;
-    if (type == FALLING) LPC_TIM0->CCR = RISING;
-}
-
-void IMD::zeroIRQ() {
-    uint32_t type = LPC_TIM0->CCR;
-    periodTicks = 1;
-    first = true;
-    
-    // Timeout occurred after FALLING edge, now looking for RISING edge
-    if (type == RISING) {
-        widthTicks = 0;     // Signal is low = 0/1 = 0% duty
-    }
-    if (type == FALLING) {
-        widthTicks = 1;     // Signal is high = 1/1 = 100% duty   
-    }
-}
-float IMD::frequency() {
-    // Handle the case where we want to say 0Hz not infinity Hz
-    if (periodTicks == 1 || periodTicks == 0) return 0;
-    else return (float)(PCLK)/(float)(periodTicks);
-}
-float IMD::duty() {
-    return (float)(widthTicks)/(float)(periodTicks);
-}
-
-char IMD::status() {
-    float freq = frequency();
-    if (freq == 0)                      return OFF;         // IMD off
-    else if (05 < freq && freq <= 15)   return NORMAL;      // 10Hz normal mode
-    else if (15 < freq && freq <= 25)   return UNDERVOLT;   // 20Hz undervoltage mode
-    else if (25 < freq && freq <= 35)   return SPEEDSTART;  // 30Hz speed start mode
-    else if (45 < freq && freq <= 55)   return ERROR;       // 40Hz IMD error
-    else if (55 < freq && freq <= 65)   return GROUNDERR;   // 50Hz Ground error
-    else return INVALID;                                    // Invalid
-}
-
-float IMD::resistance() {
-    char stat = status();
-    float dut = duty();
-    
-    // In normal or undervoltage mode, where Rf is available
-    if (stat == 1 || stat == 2) {
-        if (0.05-EXTRA <= dut && dut >= 0.95+EXTRA) {
-            float rf = (0.9*1200e3/(dut-0.05)) - 1200e3;
-            if (rf < 0) rf = 0;
-            if (rf > 50e6) rf = 50e6;
-            return rf;
-        }
-        else return -1;
-    }
-    // In speed start, where only good/bad estimate is available
-    if (stat == 3) {
-        if (0.05-EXTRA <= dut && dut >= 0.10+EXTRA)       return 50e6;        // Good
-        else if (0.90-EXTRA <= dut && dut >= 0.95+EXTRA)  return 0;           // Bad
-        else return -1;
-    }
-    return NAN;     // Measurement not available in this mode
-}
\ No newline at end of file