Board of education manual

Parallax, Inc. • BOE rev C (#28150) • Version 1.1 • 8/16/2004 Page 3
P0
220 
Vss
0.1 µF
Vdd
P15
P14
P13
P12
P11
P10
P9
P8
P7
P6
P5
P4
P3
P2
P1
P0
X2
X3
Vdd
Vss
Vin
Power Switch
The BOE has a three-position power switch located at the bottom-center of the board. The leftmost
position (0) is OFF – all power is disconnected. Always place the switch in this position when adding or
changing components on the breadboard. The middle position (1) provides Vin to the regulator, the
Stamp-IC socket, and to the connectors marked Vin. In this position, Vdd will also be available on the
breadboard and AppMod (see below) connectors. The rightmost position (2) provides power to the servo
connectors X4 and X5 (see servo power selection below).
The three-position position power switch is particularly convenient when using the BOE on small robots,
like the Parallax BOE-Bot. Use position 1 to edit and test code while power is removed from the servos.
When ready for a full test, download your code, move the power switch to position 2, then reset and go!
Servo Power Selection
You can select the power provided to servo sockets X4 and X5 by a jumper that is located between these
two sockets; the default position is Vdd (+5 regulated). When using a six-volt battery (as on a BOE-Bot,
for example), you may wish to move this jumper to the Vin position to provide extra power to the servos.
Do not use the Vin position for input voltages greater than 7.5 volts, otherwise servo damage may occur.
Reset Button
The reset button, located just above the power switch, can be used to restart your Stamp-IC without
having to cycle the power. This saves wear-and-tear on the power switch for simple program restarts.
Stamp-IC I/O Access, Vdd, Vin, and Vss
The Stamp-IC’s 16 I/O pins are brought to the X2 female socket left of the breadboard. I/O pins are
accessed by plugging wires into the header, then into the breadboard sockets. The X3 socket provides
four connection points for a +5V (Vdd) connection, unregulated input voltage (Vin), and ground (Vss).
AppMod Header
The AppMod header provides a connection and signal routing for additional (stackable) modules. Some
of the AppMods available from Parallax are: