Transcript Output Actuators and Drive Techniques

Output Actuators and Drive
Techniques
by
Prof. Bitar
System Level Block Diagram
Considering the Processing Block to
Output Actuator Interface
Input
Sensor(s)
Processing
Output
Actuator(s)
What are the Possible Outputs?
•
•
•
•
•
•
LCD Display (7-Segment, Dot-Matrix…)
LED Display (7-Segment…)
Discrete LED’s
Alarms (Speaker, Piezo-Electric…)
Computer Interface (USB, Serial, Parallel…)
Wireless (Blue Tooth, WiFi, ZigBee…)
Possible Displays…
Images from www.digikey.com
.
Audible Devices…
Note: Images from www.digikey.com .
Computer Interfaces…
Note: Images from www.digikey.com .
Cheap Wireless Modules…
• Available at www.sparkfun.com
Note: Images from www.sparkfun.com .
Processor Block to Output Device
Interfacing Concerns
• Voltage Level Concerns
• Load Current Requirements
• Protocols (for Computer Interfacing)
Example 1: LCD Display Specification Sheet
(Often a BAD Choice for ECE2799)
Note: Image from www.digikey.com .
Example 2: LCD Module Specification Sheet
(A Better Choice for ECE2799)
Note: Image from www.digikey.com .
Microcontroller Development Boards?
(Definitely a Time Saver)
Note: Images from www.sparkfun.com .
Basic Drive Techniques
• Consider a typical Red LED
+
IF
VF
IF = 20mA
VF = 2.1V
-
• What are some of the concerns here?
• How many LED’s are you trying to drive?
• Can the Processing Block handle this?
Possible Solution(s)
• Using a Transistor or MOSFET Driver
VCC
VDD
LED1
R1
Processing Block
LED1
R1
RB
Q1
T1
Piezo Alarm Example
External vs. Internal Drive
• External Drive means that a switching
signal in the audible range of frequencies
must be provided .
• Internal Drive means that the oscillating
circuit is self-contained in the device.
Piezo Alarm Example
Note: Image from www.digikey.com .