■ FIGURES 8A-8C. Modifications necessary to enclosure face for pushbutton upgrade.
the control board and add a header for the switch wire to
plug into. This can be done by adding an RA SIP header
to the Super Carrier Board as shown in Figure 9. A 10K
pull-up resistor was added, as was a 220 ohm series resistor.
Like Ringing a Doorbell
The source code was revised for the hardware changes
and the new version (V1.1) can be loaded into the control board.
Now you can set up zones by holding the button down for
approximately two seconds until all three LEDs flash three
times. At this point, the green LED starts flashing. The unit is
waiting for the Zone4 setting. For most applications, this will be
the maximum range of the sensor, so with nothing obstructing it
you can simply press the button to set the maximum range.
The sensor should not be able to see the garage door when
closed. Once you press the button to set the Zone4 range,
the yellow LED starts flashing waiting for you to set the Zone3
distance. Pull your car in to the point where you want to slow
down. Once in position, press the button again. The Zone3
distance is now set and the red LED starts flashing. The unit
is now waiting for Zone2 where you would normally stop. Pull
your vehicle into position taking care to make sure you
have exactly the clearance you want and press the button.
At this point, the Garage Parking Assistant is now
ready to use the new values for parking. Zone1 is set
automatically based on a buffer and minimum allowed
distance of six inches. Pulling ahead of the red zone will
still cause the red LED to flash, warning you to back up.
Time to Build
All the information for this project can be found on
the Nuts & Volts website at www.nutsvolts.com.
Additional information, updates, and forum discussions
can be found by visiting the project website located in the
resources sidebar. Park it and have some fun! NV
■ FIGURE 9. Modifications necessary to Super Carrier
Board for pushbutton upgrade.
Have Laptop Will Travel
While not required, a laptop is a great
help in getting everything where you want
because you can have it in the garage
with you while the code is running and it
is displaying the values so you can note
these positions when setting your Zone
constants. You will definitely want to
know what the maximum value is that your
PING))) sensor reports when no car is in
the garage. You’ll want to make sure that
value is stable and set the Zone4 constant
to this value.
BILL OF MATERIALS
ITEM DESCRIPTION SOURCE PART
U1 BASIC Stamp 2 Module Parallax BS2-IC
PCB Super Carrier Board Parallax 27130
LED1 10 mm Red LED N/A N/A
LED2 10 mm Yellow LED N/A N/A
LED3 10 mm Green LED N/A N/A
R1 470 ohms, 1/4W Parallax 150-04710
R2, R3 220 ohms, 1/4W Parallax 150-02210
PING))) PING))) Sonar Rangefinder Parallax 28015
ENC1 Project Enclosure (3x2x1") RadioShack 270-1801
ENC2 Project Enclosure PAC-TEC OD45
( 5.1x3.1x1.5" Sealed)
January 2010 33