power_mgt.cpp

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#define FASTLED_INTERNAL
#include "FastLED.h"
#include "power_mgt.h"
 
FASTLED_NAMESPACE_BEGIN
 
// POWER MANAGEMENT
 
static const uint8_t gRed_mW   = 16 * 5; 
static const uint8_t gGreen_mW = 11 * 5; 
static const uint8_t gBlue_mW  = 15 * 5; 
static const uint8_t gDark_mW  =  1 * 5; 
 
// Alternate calibration by RAtkins via pre-PSU wattage measurments;
// these are all probably about 20%-25% too high due to PSU heat losses,
// but if you're measuring wattage on the PSU input side, this may
// be a better set of calibrations.  (WS2812B)
//  static const uint8_t gRed_mW   = 100;
//  static const uint8_t gGreen_mW =  48;
//  static const uint8_t gBlue_mW  = 100;
//  static const uint8_t gDark_mW  =  12;
 
 
#define POWER_LED 1
 
#define POWER_DEBUG_PRINT 0
 
 
// Power consumed by the MCU
static const uint8_t gMCU_mW  =  25 * 5; // 25mA @ 5v = 125 mW
 
static uint8_t  gMaxPowerIndicatorLEDPinNumber = 0; // default = Arduino onboard LED pin.  set to zero to skip this.
 
 
uint32_t calculate_unscaled_power_mW( const CRGB* ledbuffer, uint16_t numLeds ) //25354
{
    uint32_t red32 = 0, green32 = 0, blue32 = 0;
    const CRGB* firstled = &(ledbuffer[0]);
    uint8_t* p = (uint8_t*)(firstled);
 
    uint16_t count = numLeds;
 
    // This loop might benefit from an AVR assembly version -MEK
    while( count) {
        red32   += *p++;
        green32 += *p++;
        blue32  += *p++;
        --count;
    }
 
    red32   *= gRed_mW;
    green32 *= gGreen_mW;
    blue32  *= gBlue_mW;
 
    red32   >>= 8;
    green32 >>= 8;
    blue32  >>= 8;
 
    uint32_t total = red32 + green32 + blue32 + (gDark_mW * numLeds);
 
    return total;
}
 
 
uint8_t calculate_max_brightness_for_power_vmA(const CRGB* ledbuffer, uint16_t numLeds, uint8_t target_brightness, uint32_t max_power_V, uint32_t max_power_mA) {
    return calculate_max_brightness_for_power_mW(ledbuffer, numLeds, target_brightness, max_power_V * max_power_mA);
}
 
uint8_t calculate_max_brightness_for_power_mW(const CRGB* ledbuffer, uint16_t numLeds, uint8_t target_brightness, uint32_t max_power_mW) {
    uint32_t total_mW = calculate_unscaled_power_mW( ledbuffer, numLeds);
 
    uint32_t requested_power_mW = ((uint32_t)total_mW * target_brightness) / 256;
 
    uint8_t recommended_brightness = target_brightness;
    if(requested_power_mW > max_power_mW) { 
        recommended_brightness = (uint32_t)((uint8_t)(target_brightness) * (uint32_t)(max_power_mW)) / ((uint32_t)(requested_power_mW));
    }
 
    return recommended_brightness;
}
 
// sets brightness to
//  - no more than target_brightness
//  - no more than max_mW milliwatts
uint8_t calculate_max_brightness_for_power_mW( uint8_t target_brightness, uint32_t max_power_mW)
{
    uint32_t total_mW = gMCU_mW;
 
    CLEDController *pCur = CLEDController::head();
    while(pCur) {
        total_mW += calculate_unscaled_power_mW( pCur->leds(), pCur->size());
        pCur = pCur->next();
    }
 
#if POWER_DEBUG_PRINT == 1
    Serial.print("power demand at full brightness mW = ");
    Serial.println( total_mW);
#endif
 
    uint32_t requested_power_mW = ((uint32_t)total_mW * target_brightness) / 256;
#if POWER_DEBUG_PRINT == 1
    if( target_brightness != 255 ) {
        Serial.print("power demand at scaled brightness mW = ");
        Serial.println( requested_power_mW);
    }
    Serial.print("power limit mW = ");
    Serial.println( max_power_mW);
#endif
 
    if( requested_power_mW < max_power_mW) {
#if POWER_LED > 0
        if( gMaxPowerIndicatorLEDPinNumber ) {
            Pin(gMaxPowerIndicatorLEDPinNumber).lo(); // turn the LED off
        }
#endif
#if POWER_DEBUG_PRINT == 1
        Serial.print("demand is under the limit");
#endif
        return target_brightness;
    }
 
    uint8_t recommended_brightness = (uint32_t)((uint8_t)(target_brightness) * (uint32_t)(max_power_mW)) / ((uint32_t)(requested_power_mW));
#if POWER_DEBUG_PRINT == 1
    Serial.print("recommended brightness # = ");
    Serial.println( recommended_brightness);
 
    uint32_t resultant_power_mW = (total_mW * recommended_brightness) / 256;
    Serial.print("resultant power demand mW = ");
    Serial.println( resultant_power_mW);
 
    Serial.println();
#endif
 
#if POWER_LED > 0
    if( gMaxPowerIndicatorLEDPinNumber ) {
        Pin(gMaxPowerIndicatorLEDPinNumber).hi(); // turn the LED on
    }
#endif
 
    return recommended_brightness;
}
 
 
void set_max_power_indicator_LED( uint8_t pinNumber)
{
    gMaxPowerIndicatorLEDPinNumber = pinNumber;
}
 
void set_max_power_in_volts_and_milliamps( uint8_t volts, uint32_t milliamps)
{
    FastLED.setMaxPowerInVoltsAndMilliamps(volts, milliamps);
}
 
void set_max_power_in_milliwatts( uint32_t powerInmW)
{
    FastLED.setMaxPowerInMilliWatts(powerInmW);
}
 
void show_at_max_brightness_for_power()
{
    // power management usage is now in FastLED.show, no need for this function
    FastLED.show();
}
 
void delay_at_max_brightness_for_power( uint16_t ms)
{
    FastLED.delay(ms);
}
 
FASTLED_NAMESPACE_END