L293D - NEX ROBOTICS LPC2148 Pro Manual

LPC2148 DEVELOPMENT BOARD
3.12 L293D 600mA Dual DC MOTOR DRIVER
Fig.3.5 Supply and motor connections
The LPC2148 development board has one L293D motor driver IC. L293D is designed to
provide bidirectional drive currents of up to 600mA at voltages from 5V to 36V. For more
information on L293D motor driver IC refer device data sheet included in the CD.
Each motor driver channel requires two I/O pins for direction control and 1 I/O pin for
velocity control of a DC motor. The motor power supply is separated from the logic supply.
The logic supply is provided from the on board power supply. The motor supply should be
provided externally as shown in fig.3.5.
Fig. 3.6
The L293D direction control port and LED port uses same pins on LPC2148 microcontroller.
So in order to use L293D driver all the jumpers on the LED header should be inserted as
shown in the fig.3.6.
The velocity of the DC motor can be varied using the PWM port on the LPC2148
microcontroller or it can be fixed to maximum velocity by connecting velocity pins to 5V.
For this purpose, LPC2148 development board has a header for selecting the source of
velocity signal.
Fig. 3.7a Fig. 3.7b
If jumper positions are as shown in fig. 3.7a, PWM channels 4 & 6 are selected as source of
velocity signal. If jumper position are as shown in fig. 3.7b, +5V is selected.
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