Multiplexing is a extremely old innovation in which manage signals are intermixed for the benefit of being able to manage much more gadgets than there are manage signals. For [mihai.cuciuc], the issues started when he multiplexed some extremely effective LEDs.
The problem? In two banks of six LEDs each, both LEDs linked to a single Arduino pin would light, even when only one bank was turned on at the ground side. The LED In the bank that was changed on lit brightly, as well as its corresponding LED in the bank that was off would likewise be extremely dimly lit. [mihai] was able to identify that the issue was not because of a leaky transistor, however rather because of a high quality of the LEDs themselves.
What is an LED however a diode, as well as it’s well understood that diodes likewise have capacitance. In fact, this high quality is exploited in varactor diodes, a specialty diode whose capacitance can be altered by diverse the voltage on the cathode. [mihai] deduced that this capacitance was triggering present to flow in the bank that was off. Where was the present going? From the Arduino pin that was on, with its connected LED, as well as then into the rest of the bank of LEDs, charging them like capacitors. [mihai] hasn’t seen this before, however theorizes that for the most recent batch of high effectiveness LEDs, this minute present is sufficient to light the LED with which the present is flowing.
[mihai]’s service is an stylish hack which he’s made offered for your perusal. You may likewise delight in this introduction to diode fundamentals by W2AEW. If you have any type of excellent diode or LED hacks of your own, be sure to decrease us a line!