Microprocessor Circuits
Cornell University ECE 4760 Designing with Microcontrollers Final Projects - Students in ECE 4760 at Cornell University were given the responsibility of choosing, designing and building a project using Atmel Mega644 microcontrollers. Projects this year include video object tracking, acoustic GPS navigator, and an automated rock band guitar player, as well as musical instruments and scientific devices. During the last 5 weeks of the semester in ECE 4760, Microcontroller Design, students have to combine sensors, actuators, microcontrollers, and mathematical techniques to build something.
µC implements Pushbutton Light Dimmers: 06/18/98 EDN-Design Ideas
10 Tricks for Interfacing to the PIC16C508:
101 AT Keyboard to ASCII Decoder: The Host to Keyboard Protocol is initiated by taking the KBD data line low. However to prevent the keyboard from sending data at the same Time that you attempt to send the keyboard data, it is common to take the KBD Clock line low for more than 60us. This is more than one bit length. Then the KBD data line is taken low, while the KBD clock line is released.
12C508 Smart Lock: The base sends a data sequence (the password) which is recognized by the key. The key checks the sequence and -if it recognizes it -sends to the base another data sequence, as an answer to the password. At the Time when the base gets a correct answer (which means that the key has been introduced), the relay is put into action, and it can command a number of consumers.
2 Wire LCD Interface using PIC16CF84:
27c801 EPROM Programmer Project:
40+ MHz 5 Digit Frequency Counter With An AVR 2313:
50 MHz Frequency Counter, Voltage Meter & SWR/PWR indicator:
68HC11 Instruction halts External RC Clock: 04/27/95 EDN-Design Ideas
68HC11 Synthesizes Accurate Sine Wave: 09/02/96 EDN-Design Ideas
8051 Development System Circuit Board:
8051 Development System Circuit Board:
AC Lamp Dimmer for Basic Stamp:
AC Vias Can Improve Decoupling: 04/28/03 Electronic Design - Ideas for Design / Good decoupling is nearly always essential in a world of mixed-signal designs that exhibit increasing speed, performance, and component density. There are cases, though, where proper decoupling is absolutely critical if the circuit is to deliver its..
Acceleration Monitor using ADXL202 and AVR
Analog input circuit serves any microcontroller:
12/20/2001 EDN - Design Ideas / The simple ADC in
Figure 1 is perfect for getting analog signals into
a purely digital microcontroller. Using just five
surface-mount parts, you can assemble it for less
than 50 cents (1000), which is approximately half
the cost of a single-chip-ADC approach in the same
volume. Moreover, this design takes only one pin
from the microcontroller to operate. .
Analog to Digital Conversion Notes for PIC Processor:
AT89C2051 / 4051 Driving Dot LED:
AT89C2051 / 4051 Easy Downloader:
AT89C2051 / 4051connecting Dumb Terminal:
AT89C2051 / 4051scanning 7 Segment Display & Keypad:
AT89C2051 / 4051Stepper Motor Interface:
AT89C2051 Digital Thermometer & Clock:
AT89C2051 Line Follower Robot:
AT89C2051 Real Time Controller:
AT89C2051 Serial Coms to LED Driver:
AT89C51 / 52 / 55 Easy Downloader:
Atmel 8051 Flash Based Microcontroller Programmer:
Atmel 89C Series Flash Microcontroller Programmer:
AVR Based Serial Port IR Receiver:
AVR microcontroller makes improved motor controller:
10/17/2002 EDN - Design Ideas / The circuit in
Figure 1 provides a novel method of reading the
pulse train using an Atmel (www.atmel.com) AVR
processor, from a typical radio-controlled receiver,
and to determine the velocity of a motor. To capture
the pulse train from a typical receiver, you need an
external interrupt that triggers based on a rising
and a falling edge..
Basic Stamp Computer Eases Prototyping hassles:
04/09/98 EDN-Design Ideas
Basic Stamp Interface Circuits:
Basic Stamp Lightning Activity Monitor:
BASIC Stamp Thermoelectric Cooler:
Build a PIC Controlled DDS VFO, 0 to 6 MHz:
Circuit Controls Two LEDs With One Microcontroller
Port Pin : 04/01/02 Electronic Design - Ideas
for Design /Microcontroller port pins can typically
be driven either high or low, or else be put into an
"input" or high-impedance state. This circuit uses
the three states to drive two separate LEDs with one
port pin. This can be very useful when there are
no...
Circuit provides watchdog for microcontrollers:
12/26/2002 EDN - Design Ideas / The watchdog
circuit in Figure 1 uses a single NAND
Schmitt-trigger IC. The circuit is more
cost-effective than dedicated, commercially
available watchdog ICs. The circuit generates an
active-high reset signal upon power-up and remains
in a low state as long as the control input receives
pulses. Whenever the pulsing at the control input
stops, whether the circuit is in a high or a low
state, th....
Closed Caption Decoder: This is a closed-caption
decoder with serial output, based on a PIC16C71, an
Élantec EL4581C sync separator, and an LM393 dual
comparator (for data slicing with automatic
threshold).
Connecting LED to PIC Micro I/O Pins:
Connecting PIC12C508 8 to 93AA46 Serial Eprom:
Controller Provides Multiple Alarm Driver Formats:
01/15/98 EDN-Design Ideas
Digital signal controls sine generator:
05/15/03 EDN-Design Ideas / The circuit of Figure 1
produces an accurate, variable-frequency sine wave
for use as a general-purpose reference signal. It
includes an eighth-order elliptic,
switched-capacitor lowpass filter, IC3, which uses a
100-kHz square-wave clock signal that
microcontroller IC2 generates. (Any other convenient
square-wave source is also acceptable...
DS1820 Arbiter V2.00 Schematic:
DS1820 Temperature Sensor Readout Unit: Dual PIC16C84 Prototype Board:
Electronic Door Codelock With PIC16F84:
Electronic Door Codelock:
Embedded System to Send E Mails (small TCP/IP Stack):
EZ80 Single Board Computer Schematic (Z80):
Freign Vocabulary Recollector:
FSK Modem With PIC16C84:
Galvanic Decoupling of I2C Bus:
Generate Video Signals: in real-time using a
PIC16F84
Giant Money Counter (PIC16F876):
GPS Repeater:
Graphic LCD Interface:
High Efficiency Halogen Bike Light Dimmer: This
circuit uses a PIC16F84 microcontroller with some
software to control20-Watt12V DC halogen lamp
Infra/radio Remote Control Transmitter/receiver With
PIC:
Interfacing DRAM to AT90S8515:
Interfacing Piezo Elements to a Microcontroller:
Interfacing S 7800to PIC16F877:
KD7LMO Micro Beacon (PIC18F252):
Key reading circuit saves I/O pins: 03/06/03
EDN-Design Ideas / Some microcontroller applications
usually use too many I/O pins to read keys or
onboard switches; in many cases, few pins remain
available for other uses. Some alternative ways to
read keys yield more free pins. First, consider some
ways to effect key reading. Table 1 presents a
comparison of four methods with references to
circuit configurations (figures 1, 2, 3, and 4)
Kodak DC 20 Camera Interface (PIC12C509):
Kodak DC 20 Camera Interface (PIC16F84):
Low Cost Digital Thermometer Uses SingleChip
Microcontroller : 02/18/02 Electronic Design -
Ideas for Design / In many applications, the ability
to read and display temperature is either desirable
or an absolute requirement. Some of these
applications include temperature probes,
thermostats, CPU monitors, and process-control
equipment. The ...
Low Voltage Reset operates Below 2.7V: 03/26/98
EDN-Design Ideas
Mains Clock Controller using AT89C2051:
Make a DAC with a microcontroller's PWM timer:
09/05/2002 EDN - Design Ideas / Many
embedded-microcontroller applications require
generation of analog signals. An integrated or
stand-alone DAC fills the role. However, you can
often use PWM signals for generating the required
analog signals. You can use PWM signals to create
both dc and ac analog signals. This Design Idea
shows how to use a PWM timer to simultaneously
create a sinusoid, a ramp, and a dc voltage..
Make noise with a PIC
: 08/07/03 EDN-Design
Ideas / Building a stable noise generator for
audio-frequency purposes requires only a few
components. The circuit in Figure 1 relies on
linear-feedback shift registers and some simple
software. An eight-pin Microchip (www.microchip.com)
PIC12C508 controller (IC2) with a short program
generates pseudorandom noise at its output pin,
GP0....
Microchip PIC ICD (in Circuit Debugger):
Microchip PIC ICSP implementation:
Microcontroller Becomes Multifunctional:
10/25/01 EDN-Design Ideas / PDF contains multiple
circuits - scroll to find this circuit.
Microcontroller directs supply sequencing and
control: 05/29/03 EDN-Design Ideas / With the
proliferation of dual-voltage architectures and
multiprocessor boards, even simple applications can
require several processor voltage rails. With each
processor having its own power-up and down
requirements, power-rail sequencing and control can
become a complex task. The challenge for
power-supply designers is to consider each
processor's timing and voltage requirements and
assimilat....
Microcontroller discerns addresses in RS 485 systems:
11/08/2001 EDN - Design Ideas / One of the many
benefits of using the RS-485 data-interface system,
unlike the RS-232 system, is its ability to
implement multidrop networks. Such networks usually
carry 9-bit data words, in which the ninth (parity)
bit identifies each word as address or data. When
using small microcontrollers without a hardware UART,
such as IC1 in Figure 1, designers must decide
whether to add an exte... .
Microcontroller emulates numerically controlled
oscillator: 02/21/2002 EDN - Design Ideas /
Microcontrollers commonly add intelligence or
digital functions to products, but they can also
provide a variety of analog signals. An 18-pin PIC
16C54 microcontroller, combined with an inexpensive,
8-bit DAC and a simple lowpass filter, can generate
sine waves from dc to approximately 50 kHz with a
tuning resolution of 24 bits. .
Microcontroller emulates numerically controlled
oscillator: 02/21/2002 EDN - Design Ideas /
Microcontrollers commonly add intelligence or
digital functions to products, but they can also
provide a variety of analog signals. An 18-pin PIC
16C54 microcontroller, combined with an inexpensive,
8-bit DAC and a simple lowpass filter, can generate
sine waves from dc to approximately 50 kHz with a
tuning resolution of 24 bits. . Microcontroller Interface for 5KWatt Microwave oven:
Microcontroller Makes Effective Frequency Counter:
11/23/00 EDN-Design Ideas / PDF contains multiple
circuits - scroll to find this circuit.
Microcontroller Multi Channel Light Dimmer:
Microcontroller MultiChannel Light Dimmer: The
project is a microprocessor-controlled multiple
channel lighting dimmer, that could be used in
theatrical and other applications. The device will
accept input from a wide range of interfaces: RS232
input, DMX512 (theatrical lighting standard) or
RS485, or a Musical Instrument Digital Interface
(MIDI). The device will control a number of lamps by
using some form of AC power control. The firmware in
the microcontroller will handle all functions, from
decoding the protocol on either of the input
interfaces through to Timing the firing of power
triacs for the output.
Microcontroller provides SRAM battery backup:
06/26/03 EDN-Design Ideas / To maintain content in
the event of power loss, many designs that include
SRAM require a dedicated device that can
automatically switch from a standard power supply to
battery operation. Microcontrollers seldom find use
in power-switching applications. Because
microcontrollers typically operate from the primary
power supply, they stop execution if that supply
drops, thereby making it impossible....
Microcontroller selects minimum/maximum value:
09/20/2001 EDN - Design Ideas /
Microcontroller-based systems for measurement,
sensor-data processing, or control, sometimes
require you to determine a maximum or minimum data
value. For example, in an object-detection system,
such as a radar or sonar system, the microcontrolle.
Microcontroller Sensor and Actuator Interfaces:
Microcontroller Watches, Controls AC Power:
06/22/95 EDN-Design Ideas circuit allows an isolated
microcontroller to both sense and control ac power
to an externally plugged-in device
Mk2 PC Based EPROM Programmer:
MMC to PIC16F876 Circuit Diagram:
Multimedia Electronic Crib: microcontroller
based light controller which generates sequence of
day-night with light fading, optional serial control
interface, based on 87C51
Network Time Protocol AVR Clock:
Night Light Saver (PIC12C508):
No Parts PIC Micro Programmer:
One Microcontroller Serves Multiple External
Interrupts: 02/01/01 EDN-Design Ideas / PDF
contains multiple circuits - scroll to find this
circuit. Optical Sensor using PIC12C508:
PIC 18 Programmer (PIC18F458, PIC18F452, PIC18C252,
PIC16C745, PIC18F6620, PIC18F6720):
PIC Based Keyboard Emulator:
PIC Based Motor Controller:
PIC Based Packet Radio Encoder: PIC Based Web Server:
PIC Controlled DDS VFO, 0 to 6 MHz:
PIC Controlled DDS VFO, 0 to 6 MHz:
PIC Micro Multiple Servo Motor Interface:
PIC Microcontroller Servo Motor Interface:
PIC Programmer for Serial Port:
PIC Programmer: to download programs into PIC
microprocessors.
PIC Programmers for Parallel Port:
PIC Project #1 RS232 to I2C Interface:
PIC X1 Schematic (PIC16F877):
PIC12C508 Phase Controller for 2kW heater:
PIC12C509 Logic gate Replacement for Nitrogen Filler:
PIC16C505 IR / Wireless Remote Control:
PIC16C63 MIDI Controlled Light Dimmer:
PIC16C84 VT 52 Emulator for Linux:
PIC16C84 VT 52 Emulator for Linux:
PIC16F84 Based Morse Code Reader:
PIC16F84 Countdown timer:
PIC16F84 Line Following Robot:
PIC16F84 Line Following Robot:
PIC16F84 Miniature Real Time Controller:
PIC16F84 Pulse Monitor With Date/time Output (ZIP):
PIC16F84 Serial I / O Expander With PicBasic:
PIC16F84 Sound Controlled Christmas Lights:
PIC16F84 Stepper Motor Controller:
PIC16F84 tone Generator (6 Bit):
PIC16F84 tone Generator With Source Code:
PIC16F84 TrIAC / IGBT Brightness Phase Controller:
PIC16F84 Ultrasonic Range Finder Project:
PIC16F84 Web Server:
PIC16F873 Digital Clock:
PIC16F873 Remote Display:
PIC16F873 ultrasonic Range Meter:
PIC16F877 Programmer and Development System:
PIC18 Schematic:
PIC18F252 Bootloader Schematics:
PICADC a Free, PIC Based "intelligent" a / D
Converter:
PicCon Hidden Radio Transmitter Controller:
PICDIM Application Note: This is a lamp dimmer
design based on PIC12C508 microcontroller.
PicoWeb V5.1 (AT90S8515) tiny Web Server:
Picxie 2 8x8 Animated LED Signboard:
Programmable Clock Oscillator: PIC-Tock video
clock using a PIC16C61
Programmer for the 68HC705C8 MicroController:
Programmer PIC16F84,12C50x and EEPROM 24Cxx: Propellor Clock (PIC16F84):
Record and Play Fast 1 Bit Sound on a PIC Micro:
Remote Control Encoder/decoder With PIC16C620 &
PIC12C508:
Remote Control for Raymarine ST4000 Autopilot:
Rotating Sprocket Wheel Generator (PIC16F84):
RS 485 RPT Schematic:
RS485 Like Multi Drop Bus With half Duplex Serial
Protocol:
RS485 Version of the SAB80C535 Microcontrollerboard: ScanMate Audio Activated Recorded:
Ser Key 10 Key Serial Keypad Encoder:
Serial Port Break Reset Circuit:
Serial to Parallel Converter using the AT89C2051:
Speaking Clock using PIC & ISD Device: SpeClo
was designed and built to be used by the blind. Its
purpose is to provide a relatively easy way for
ascertaining the Time of day by whistling, and can
be configured to speak English or German!
Speaking Doorbell: SpeDoB was designed and built
to gain experience with the PIC microcontroller.
This doorbell uses a speech recorder integrated
circuit (ISD series) to play back3 pre-recorded "theres
someone knocking on the door" messages. Its a very
easy and simple project to build, ideal for
beginners!
Speech Recognition using HM2007:
ST6 Microcontroller & TrIACs on Mains: includes
dimmer circuit example
ST6 Microcontroller & TrIACs on Mains: includes
dimmer circuit example
Talking PIC Based on SP0256:
Talking YODProject (PIC16C84):
Temperature Controlled Based on AT89CX051:
Temperature Monitor/controller: AVR 2313 / DS1621: Temperature Sensitive Oscillator: Temperature
controlled based on AT89CX051
Ten Tricks for Interfacing to thePIC16C508:
Thermistors and a Microcontroller Simplify
Anemometer Design : 10/14/02 Electronic Design -
Ideas for Design / Typically, air flow is measured
with a hot-wire anemometer. Here's an alternative
version of that concept using two thin-film platinum
resistance temperature detectors. A high-performance
mixed-signal microcontroller can make the
measurement and drive...
Thermistors and a Microcontroller Simplify
Anemometer Design : 10/14/02 Electronic Design -
Ideas for Design / Typically, air flow is measured
with a hot-wire anemometer. Here's an alternative
version of that concept using two thin-film platinum
resistance temperature detectors. A high-performance
mixed-signal microcontroller can make the
measurement and drive... Thermoelectric Controller (scriptable Thermometer): Tony Nixons Pocket Programmer (PIC):
Two Wire LCD Interface using PIC16CF84:
Use Four External Interrupts Through One 8051 Input
: 05/13/02 Electronic Design - Ideas for Design
/ The 8051-compatible microcontrollers are equipped
with up to two inputs that may be used as
general-purpose interrupts. A simple way to increase
the number of interrupt inputs is shown in the
figure. The...
Using An I2C Serial EEPROM With a Basic Stamp 2:
Victoria TaFE Programmer (based on AT89C2051):
Voice Recording and Message Retrieval System:
Wisp628 ISP Microchip PIC Programmer:
World's Smallest PIC Programmer:
WWWpic2 a Web Server in a PIC:
Zilog Z80 thermostat Embedded Web Server: