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64d729e Nov 2, 2017
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@focalintent @NicoHood @kriegsman
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#define FASTLED_INTERNAL
#include "FastLED.h"
#include "power_mgt.h"
FASTLED_NAMESPACE_BEGIN
//// POWER MANAGEMENT
// These power usage values are approximate, and your exact readings
// will be slightly (10%?) different from these.
//
// They were arrived at by actually measuing the power draw of a number
// of different LED strips, and a bunch of closed-loop-feedback testing
// to make sure that if we USE these values, we stay at or under
// the target power consumption.
// Actual power consumption is much, much more complicated and has
// to include things like voltage drop, etc., etc.
// However, this is good enough for most cases, and almost certainly better
// than no power management at all.
//
// You're welcome to adjust these values as needed; there may eventually be an API
// for changing these on the fly, but it saves codespace and RAM to have them
// be compile-time constants.
static const uint8_t gRed_mW = 16 * 5; // 16mA @ 5v = 80mW
static const uint8_t gGreen_mW = 11 * 5; // 11mA @ 5v = 55mW
static const uint8_t gBlue_mW = 15 * 5; // 15mA @ 5v = 75mW
static const uint8_t gDark_mW = 1 * 5; // 1mA @ 5v = 5mW
// 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