This week we were supposed to measure the power consumption of an output device.
We worked with Kati's NeoPixels (WS2812B), which has 60 LEDs per one meter, to measure the power consumption of an output device. We used a power supply to measure the power consumption. It was basically really easy, because the power supply provides the power on the screen.
For testing the NeoPixels we used the test program found from Adafruit NeoPixel Library.
By navigating into a Sketch > Include Library > Manage Libraries we searched and downloaded the Adafruit Neopixel by Adafruit Version 1.1.6 -library which is an Arduino library for controlling single-wire-based LED pixels and strip.
Then, by navigating into a File > Examples > Adafruit NeoPixel > simple we opened this example code by Adafruit.
This first test was an example with all LEDs on and set to light up one by one as green.
We set the limiting voltage to 5.00 V and the current to 3.5 A, which results to 17.5 W (P = UI), but since the actual current output was 0.48 A, the real power was 2.4 W.
Second, we tested an example program called RGBWstrandtest from the same Adafruit NeoPixel Library, which was blinking LEDs in a predefined order. In the second run, the power consumption was naturally lower, because the amount of leds on at each moment were less than in the first test (current 0.162 A). The power consumption in the second test was 0.8 W.