Servomotor 3 – Servomotor 4 to Servomotor 5 –
Servomotor 6. Servomotor 5 and 6 are controlled by the
right analog stick as long as the left 1 button is pressed.
Releasing the left 1 button will shift control of the right
analog stick back to Servomotor 3 and 4.
The servomotor has a maximum limit in both directions
and driving it beyond these limits will cause damage to the
servomotor and drain heavy current from the power supply.
To avoid this, servomotors are not allowed to be driven
beyond their Pulse Width (PW) limits, as determined by the
manufacturer’s recommendation for PW signals sent to the
servomotor. When any of the servomotors have reached
their limit and the user continues trying to move it by tilting
the corresponding analog stick, the servomotor will not
move and this condition will be indicated by a Rumble
(force feedback) feature. Rumble will stay on as long as the
user keeps the stick tilted.
The PS2 SMC can be configured in three different
operating modes. These modes can be changed “on-the-fly”
during normal operation. New mode selection is stored in
the non-volatile memory of the PIC. The stored mode will
automatically load the next time the PS2 SMC is turned on.
1.) Mobile Platform Mode – MPM
(Circle and Square Buttons)
In this mode, Servomotor 1 and Servomotor 2 are
configured as differential drive in a moving platform (for
continuous rotation servomotors). To activate the MPM,
press the Circle button.
Pressing the Square button will select the Normal
Independent Mode (NIM) for servomotor control. This
mode is for standard servomotors and not continuous
In MPM mode, the left analog stick will act as a
navigation control with built-in speed control. Tilting the
stick upwards will result in forward motion; downwards is
for reverse motion; left is for left turn; and right is for right
FIGURE 12. Servomotors mapped to PlayStation controller.
FIGURE 13. Mobile test platform.
FIGURE 14. Reduced size PCB for mobile
operations on robots.
(1) Printed Circuit Board
(1) ICS- 18
( 5) 1N5401-!N5402
(1) Sub-min LED
(1) Green LED
( 6) Three-Pin Straight Male Header
(1) Seven-Pin Straight Male Header
(1) 8.0 MHz Crystal
(1) 7805 (Voltage Regulator)
( 2) 1K ohm 1/4 watt Resistor
( 2) 4.7K ohm 1/4 watt Resistor
(1) 10K ohm 1/4 watt Resistor
(1) 2. 5 mm PC Power Jack Connector (PJ-102B)
(1) 12 mm Momentary Switch Tact (SW- 25)
(1) Toggle Switch SPDT On-On PCM (SW-07)
( 2) 10 μF Capacitor, 16V
(1) 0.1 μF Capacitor, 100V
( 2) 22 pF Capacitor, 50V
( 2) 1,000 μF Capacitor, 10V
(1) PIC16F88 Microcontroller
(1) Seven-Position Modular to CS Connector
(1) 9 VDC 300 mA. (or greater) Power Supply
A complete or partial kit to go with this article can be
purchased online from the SERVO Webstore www.servomagazine.com
or call our order desk at 800-783-4624.
SERVO 02.2011 61