Friday, December 13, 2013
Telephone Conversation Recorder
This circuit enables automatic switching-on of the tape recorder when
the handset is lifted. The tape recorder gets switched off when the
handset is replaced. The signals are suitably attenuated to a level at
which they can be recorded using the ‘MICIN’ socket of the tape
recorder.
Points X and Y in the circuit are connected to the telephone lines.
Resistors R1 and R2 act as a voltage divider. The voltage appearing
across R2 is fed to the ‘MIC-IN’ socket of the tape recorder. The values
of R1 and R2 may be changed depending on the input impedance of the
tape recorder’s ‘MIC-IN’ terminals. Capacitor C1 is used for blocking
the flow of DC.
The second part of the circuit controls relay RL1, which is used to
switch on/off the tape recorder. A voltage of 48 volts appears across
the telephone lines in on-hook condition. This voltage drops to about 9
volts when the handset is lifted. Diodes D1 through D4 constitute a
bridge rectifier/polarity guard. This ensures that transistor T1 gets
voltage of proper polarity, irrespective of the polarity of the
telephone lines.
Pick Kit2
Q1 BC547
Q3 BC547
Q4 BC547
Q2 BC557
C3 22pF CAPPTH
C4 22pF CAPPTH
C6 100nF CAPPTH
C5 0.47uF CP
C1 10uF CP
C7 100uF CP
D1 DIODE1N4148
L1 680mH L
LED1 LED 5MM BLUE LED
LED2 LED 5MM RED LED
1 PIC18F2550
JP1 PINHD-1X6
R1 1K R
R3 2K2 R
R2 4K7 R
R10 4K7 R
R15 4K7 R
R16 4K7 R
R5 10K R
R6 10K R
R8 10K R
R17 22k R
R4 100K R
R7 100R R
R9 100R R
R13 100R R
R14 100R R
R11 330R R
R12 330R R
X1 USBPTH
XTAL1 20 MHz XTAL
PIC Kit2 Clone
This programmer is built around Microchip’s PICKIT2 programmer, which is basically a surface mount, fully assembled, ready to use product. It’s called a “Kit” but it is not!! This one is a true kit for radio amateurs.
Benefit of making PICKIT based programmer for amateur radio is further supported by freely downloadable PICKIT2 software for windows. Microchip keeps this software updated for new devices that they launch.
In this project, to make it simple, I have removed the voltage level change capability of firmware for VDD 3V. Means, this programmer will only program 5V PIC Micros.
Project uses a PIC16F2550 in 28pin DIP package. All diodes are standard lead type & FETs are either in TO92 or HEXDIP packages, to make assembly smooth & easy.
Kit is supplied with FD-PB1 Programming board. PB1 uses standard IC Sockets for 40, 28, 8,14, 20 & 18PIN DIP PIC Micros.
In view to make a suitable metal case for this programmer, FD-UPP has two headers H1 & H2, which will be used by “piggy back” Programming board I will design later.
For complete intro on PICKIT2, documents & PC software
Pickit 2 Schematic / Circuit Diagram:
DigiKey is shown below.
Friday, November 15, 2013
Module 2: Embedded system design.
Module 2: Embedded system design.
Chapter 1: Circuit
design and simulation
1.
Circuit
design principles.
2.
Circuit
design software.
3.
PCB
Etching.
4.
Component
mounting.
Chapter 2: Computer Organization & Architecture
1.
Function
of a computer.
2.
Computer
System Organization.
3.
CPU
Operation.
4.
Single-core
computer.
5.
Multi-core
architectures.
6.
BIOS.
7.
Block
Diagram of Typical Computer.
8.
Serial
and Parallel Communications.
Chapter 3: Introduction to
Microcontrollers
1.
What
is a Microcontroller?
2.
Why
are Microcontrollers used?.
3.
Internal
architecture.
Chapter 4: Introduction
to computer programming
1.
What
is computer program?
2.
Multi-level
machine.
3.
Multilevel
Architecture.
4.
Components
of Instructions.
5.
Level
1 Machine Language (Assembly Language).
6.
Hi level
Languages.
7.
Compilers.
8.
Interpreter.
9.
MPLAB
Installation.
Chapter 5: Simple
LED Projects
1.
Project
1- Flashing LED
2.
Interfacing
a press-button switch
3.
Flashing
LEDs in knight-rider pattern.
Chapter 6: Seven Segment Display
1.
Mod
10 counter (Single Digit)
2.
Mod
10000 counter (Four Digits)
3.
Flashing
LEDs in knight-rider pattern.
4.
Interfacing
a switch – a button press counter
Chapter 7: Liquid crystal Display.
1.
Type
of LCD’S
2.
LCD
controller
Chapter 8: Interrupts handling.
1.
What
is an interrupt
2.
Software
Interrupts
3.
Keypad
controller.
Chapter 9: RS232 Communication
1.
Introduction
To Serial Communication.
2.
Bi-Directional
Communications.
3.
Communicating
by Bits.
4.
The
Parity Bit.
Chapter10: Stepper Motors.
1.
Motors
Type
2.
DC
Motors.
3.
Servo
Motors.
4.
Full
step phase sequence
Chapter11: DAC
& ADC
1.
What
is an interrupt
2.
Software
Interrupts
3.
Keypad
controller.
Chapter12: Transducers
1.
What
is an interrupt
2.
Software
Interrupts
3.
Keypad
controller.
Chapter13: Pulse
Width Modulation
1.
What
is an interrupt
2.
Software
Interrupts
3.
Keypad
controller.
Chapter14: Memory
Technology
1.
What
is an interrupt
2.
Software
Interrupts
3.
Keypad
controller.
Chapter15: Port
programming
1.
What
is an interrupt
2.
Software
Interrupts
3.
Keypad
controller.
Chapter 16: Mini Project.
1. Submit Project Proposal.
2. Approval of Project.
3. Implementation.
4. Presentation.
Brake Down
Of Duration:
·
Lecture : 80 Hr s
·
Practical
: 80 Hrs
·
Self-Study : 100 Hrs
·
Assignments
: 10Hrs
·
Exam : 3 Hrs
·
Total : 273 Hrs
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