Teachers having to train themselves for the new English Computer Science syllabus, have a lot to learn in a short time.
Many have no experience of handling and working with electronic components, as I recently discovered.
So this post expands upon my earlier post: How To Drive LEDs From A RaspberryPi, and is taken directly from my class notes produced for young Computer Science students.
Using Breadboard
In electronics, breadboard is used to quickly construct a circuit for experimentation or prototyping.
It is never used as a permanent or
final circuit board in electrical products.
The holes in the breadboard are like
miniature electrical sockets, and are designed so suit most common
electronic components including resistors, capacitors, diodes,
transistors and integrated circuits.
Some of the holes on this breadboard
are joined together, so it is important to know which are, and which
are not connected.
Left-hand side “+”
column holes are all connected to each other, but not to anything
else.
Left-hand side “-”
column holes are all connected to each other, but not to anything
else.
Right-hand side “+”
column holes are all connected to each other, but not to anything
else.
Right-hand side “-”
column holes are all connected to each other, but not to anything
else.
These “+”
and “-” holes are generally used for
external power supply connections.
The left-hand numbered rows are
connected as follows:-
1a, b, c, d, and e are linked
to each other, but not to anything else.
2a, b, c, d, and e are linked
to each other, but not to anything else.
...and so on for each numbered row up
to 30.
The right-hand numbered rows are
connected as follows:-
1f, g, h, i, and j are linked
to each other, but not to anything else.
2f, g, h, i, and j are linked
to each other, but not to anything else.
...and so on for each numbered row up
to 30.
Wiring the Flashing LED Circuit
This is an experimental circuit for use
with the RaspberryPi.
Note:
although the breadboard numbers and letters are not important, we are
going to use them for reference when building this circuit.
Hold the LED so you can clearly
identify which is the longer of the two leads (legs).
Carefully press the LED into the
breadboard so that the longer lead goes into hole j10 and the
shorter one into j11.
The LED leads are the same “pitch”
as the holes, so they do not need to be bent.
Now take the 220 Ohm resistor and hold
it between thumb and fore finger. Carefully bend one lead over your
thumb nail to create a 90degree bend. Turn the resistor around and do
the same with the other lead. You should leave a straight section of
lead close to the resistor body.
The leads on your resistor should now
be parallel, roughly the same length, and look a bit like this.
Insert your resistor into the
breadboard so that one lead is in hole i10 and the other is
further down the board in another “i” hole, like this.
My resistor is in i16 but yours
may be slightly higher or lower, depending upon how you bent the
leads.
You can now plug in the two jumper
leads so that one is connected to row 10 (I've used f10) and
the other connects to the end of the resistor which is NOT connected
to the LED (I've used f16).
Remember
the golden rule in Engineering: “IF IN DOUBT, ASK!”
Now get a friend to check your circuit.
If its OK, you are ready to connect it
to the RaspberryPi as described here
No comments:
Post a Comment