LEDs
5 out of the 37 sensors are some sort of LEDS:
First we have the standard LEDs (not part of the sensor kit)
As you can see from the photo LEDs have leads with different length, the longer one being the anode and must therefore be connected to the + pole. The current through the LED must be limited to some tens of mA, which means that we need a resistor (typically 330
Ω if the LED is powered with 3.3 V) as shown in the circuit diagram.
2 colored LEDs
The sensor kit has 5 LED circuits which feature multi-color LEDs. First there are 2 color LEDs with exactly the same functionality but different LED sizes.
We need a 330
Ω resistor from the “-” pin to ground. The “S” pin lights the green diode, whilethe middle pin lights the red diode.
In addition to the 2 colored LED there is a tiny red SMD LED with its associate current limiting resistor. This can be activated
through pin 2 (+) and pin 3 (S, now “-”, note that S is the “+” pin when accessing the 2-colored LED)
rgb LEDs
Again we have 2 circuit boards with essentially the same functionality.
However, the rgb LED with the standard LED shape has 1k
Ω current limiting resistors already installed on the PCB while the surface mount (flat) LED does not.
So … be careful!
The flashing colored LED
This LED automatically cycles through different colors and flashes. It is connected like the simple LED. In addition to the flashing colored LED there is the IR (infra red)
transmitter which is hardly distinguishable from the flashing LED. The plastic bag containing the PCB however is clearly marked.
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Not to be confused with this -> |
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The Laser
In contrast to the LEDs the laser can be directly connected to 3.3V.
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Uli Raich - 2017-01-03
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