Using the DIYPNP Proto Areas

The DIYPNP has two proto areas on the main
board, and some versions have additional proto space on the
adapter board. The holes in these proto areas are interconnected
to make building circuits easier; connected holes are indicated
by white dots in between the holes. These proto areas give
you room to build model specific circuits your application may
need, or just to get creative and try out new circuits. Here,
we'll show you a couple examples of circuits you may find useful
on certain cars. It's also possible to make circuits in the
proto area for applications such as nitrous control, EGT
logging, speed sensor inputs - the possibilities are only
limited by the code and your imagination.

This picture shows the connections on
the proto area on the main board in blue-green lines. The
N42 board has similar, extra proto areas on it for even more
circuitry if you should happen to need it. Here are two
examples of circuits that some users might find handy. Click
on the images for a larger view.

First circuit is a 3 wire IAC driver
circuit. This one uses a pair of TIP120s to drive the opening
and closing coils of a 3 wire idle air control valve. While the
B55 board has this built in, some cars that use the N76 board
(particularly Toyota and Subaru products) also use versions of
the 3 wire IAC valve. This circuit takes the IAC signal and
splits it into two opposite signals. The IAC_Open output is
grounded when the input is grounded, and the IAC_Close output is
grounded when the input is not grounded.

The above circuit is one we designed for
controlling a VTEC solenoid. While normal relay control circuits
work by switching the ground to a relay, Honda used their ECU to
supply 12 volt power to the VTEC solenoid. This circuit uses a
TIP125 PNP Darlington transistor to power a solenoid with a
current limit of up to 5 amps. The part marked "To MS CPU" can
be connected to any of the logic level on/off outputs: PT6, PT7,
or PA0.

This alternate VTEC control circuit uses
WLED or ALED as an input. Which one to use depends on what
outputs you have available. It could also use the IAC output as
an input, but normally you would be using that for idle control.

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