location D10. Solder and snip the leads.
• Insert the two 10-pin straight female
headers from the top of the board,
and solder the pins in place on the
bottom of the board. In order to make
sure the two headers are correctly
aligned, you can use your completed
LED display board as follows:
• Place the LED display board upside-down on a flat surface.
• Insert the two straight female
headers onto the pins of the LED
board’s male headers.
• Inspect the board carefully for
accidental solder connections or other
We’re just about out of space this
month, but we still have room for a quick
test of the complete stripboard sandwich.
A simple testing program (LED27test
ABC.bas) is available with the downloads.
We can’t discuss how it works this time,
but you can still use it to test your project.
Figure 10 is a photo of my LED-2x7
installed on a breadboard and running
the test program. (The power and ground
connections are not visible because they
are behind the LED-2x7.) As you can see,
I’m using the AxMate-FT programming
adapter to power and program the
board. Of course, you can set up your
breadboard circuit using any adapter you
have on hand. When you download
and run LED27testABC.bas, you should
see a repetitively changing pattern that
has the following characteristics:
• At any given time, only one segment
is lit on each digit.
Next time, we’ll get into the software
details of untangling the “illogical” I/O
connections to the LED display segments.
However, there are quite a few hints
embedded in our little test program, so you
may want to tackle that task on your own.
We’ll also experiment with IR input to
the LED-2x7 board, as well as temperature
measurement. Even if you decide not to
construct the LED-2x7 board, you will
be able to use simple breadboard
circuits for our experiments next time.
In the meantime, have fun! NV