■ FIGURE 9. Breadboard double-sided
■ FIGURE 10. Placing the
■ FIGURE 11. Shorting Blocks Installed.
after you get it into place.
The final step is to install the shorting blocks to the
two-pin LED headers. This can be a little tight for big
fingers, so I used needle-nose pliers (see Figure 11). When
you want to disconnect the LEDs, place the shorting
blocks sideways on just one pin so they stay with the
board but don’t complete the connection. The shorting
blocks stay tight enough on one pin to not fall off.
We now have the board shown in Figure 1 completed
and ready for development. There is one problem I found,
though. Once I built a project on the breadboard area to
save it for later, I either had to build another board like
this or disconnect all the wires and start the new project.
More of these boards are available for a very reasonable
www.microchipdirect.com or other suppliers
such as Digi-Key, under part DM164120-1.
As an alternative to creating a whole new board, I
decided to stack them instead. Many years ago, I
developed this concept for a very complicated and
expensive development board with lots of added features.
My solution was to create a stacking board that contained
only a breadboard area, with a header to connect to the
other circuitry. This allowed me to simply plug in a new
board and unplug the project when I was done. I decided
to try that here with one of the blank low pin count
demo boards. Figure 12 shows the
final board being stacked on top of the
board I just built.
To create the stacker board, I used some of the same
parts, but this time started with the blank board shown in
Figure 13. Also, I added 10-pin male headers instead of
two-pin headers to the collection.
The first step is to solder the 10-pin male headers to
the bottom of the board, as shown in Figure 14. The male
headers should be in the same row as the 20-pin female
headers we installed on the completed development
Next, flip the board over and solder the 10-pin female
headers next to the male headers. I used the same
method again of soldering one pin, to allow me to
straighten them. Figure 15 shows the result.
The final step is to install another breadboard (see
Figure 16) to this blank board. You don’t have to worry
about squeezing it in because of the open space. If you
want to add the other components you can, but they will
be connected in parallel with the components underneath
on the main development board.
Figure 17 shows how — when the stacker is installed
— the PIC16F690 is cleared, as are the programming pins
that connect to the PICkit 2 programmer. This is a lower-cost way to build multiple projects and
■ FIGURE 12. Stacking the boards.
■ FIGURE 13. Stacker board
■ FIGURE 14. Headers installed on
bottom of board.