C-52 Evb Robot Controller -  Use a C-52 EVB for simple robot experiments.  Build a simple two wheels robot with L293 H-Bridge driver and IR sensor.  Write a C program controls robot tracked with black tape.   __ Designed by Wichit Sirichote

Cable tester is fast & cheap -  09/24/98 EDN-Design Ideas NOTE :  multiple circuits, scoll to this one.  The cable tester in Figure 1 uses a low-end 8-bit µC.  The specific µC to use depends on the number of conductors in the cable you want to test.  For the current application, two types of cables were under test, one with three conductors and another with seven.  So, the Motorola 68HC705P9 µC was suitable.  The program first determines which type of cable is under test by checking the cable-switch position    (Listing 1) .  Then, the program checks each conductor line from A0/C0 to A7/C7 by putting a high-level voltage from output port A on one end of the wire and measuring the response on the other end, which is connected to the input port C.  If all of the checks show conductivity, the green "pass" LED turns on.   Design by Abel Raynus, Armatron International, Melrose, MA

Camera Subs as a Scope Camera -  12/09/99 EDN-Design Ideas A digital camera can be a handy substitute for an oscilloscope camera for older scopes that cannot output hard copy or digital data.  A digital camera provIdeas instant results and allows you to easily enhance the image and then ad Design by Allen Moore, Redmond, WA

Candle Simulator -  This PIC Project  uses a PIC to simulate the flickering of a candle entirely in software.  The brightness of the lamp is controlled by doing PWM  (pulse width modulation) of the power to the lamp.  A random number generator controls the flickering amplitude.   __ Designed by Luhan Monat, Mesa, AZ

Car Network Device -  PIC Project  Our present car controller runs on a single PIC16F870 micro and provides functions for remote door locks, headlight reminder, and car finder.  It is constructed using wire-wrap to allow for future expansion and is mounted using Velcro on the passenger side of the center console __ Designed by Luhan Monat, Mesa, AZ

Casio QV-200 Digital Camera Cable -  Lose your cable? Build it yourself and save $29.  Fits many QV models __ Designed by Bob Blick

Cat Toy with a Small Weighted Motor -  The PIC12F675 is small in size and low in power.  It lends itself to some really off-beat uses __ Designed by Luhan Monat, Mesa, AZ

CD Compressor for Cars or the Home -  Do you have problems listening to CDs in your car? Are the soft bits too soft and the loud bits too loud? Here's the solution.__ SiliconChip

CD ROM Drive as Digital Audio CD Player -  This circuit converts CD ROM drive in computers into a standalone audio CD player by just connecting power supply options to CD ROM and interconnecting it to either a tape deck or an audio amplifier.   __ Designed by M.P.VERMA

CentronICs Port D/A converters & low-pass filter -  JDAC and CENT_DAC are both simple Digital to Analogue converter to use with your IBM PC/AT or compatible.  Those circuit are connected to Centronics parallel port and does not affect the normal port usage in any way.  The circuits are transparent to computer, so it is not possible to program to see if those devices are connected or not. __ Designed by Tomi Engdahl

cheap UV EPROM eraser -  An "anti-bacterial" toothbrush holder, a single capacitor and a simple IC carrier are all you need for a fully-functioning EPROM eraser.__ SiliconChip

Cheap-N-Easy 433MHz Sniffer -  Here's a simpleand cheaplittle 433MHz receiver that has many uses.  It is ideal for checking that a suspect 433MHz "wireless" device  (and there are scads of them) is actually working.  It's great for finding out where interference is coming from.  But most importantly  (we believe!) it makes a great tracker for "fox hunts" and the like.__ SiliconChip

Cheap'n'Simple Circuit 100V Speaker/Line Checker -  This Speaker/Line Checker will be a boon to anyone setting up 100V PA systems, especially for temporary installations at sporting events, when you need to do everything quickly before the event and be sure that it is all working.  With this tester, you can immediately check each PA speaker and line as it is run.__ SiliconChip

Circuit "feeds" CMOS Devices -  10/09/97 EDN-Design Ideas To retain the data of CMOS devices, such as real-time clocks or setup RAM, you need to provide power to these devices while the rest of the circuit is off.  The conventional solution uses a CMOS switch, such as the CD4066.    Design by Luis H Loss, Iochpe-Maxion, Porto Alegre, RS, Brazil

Circuit & Software Provide Accurate Recalibration for Baseline PIC Microcontroller’s Internal Oscillator -  05/01/08  EDN-Design Ideas A simple circuit and an assembly-language program allow you to recalibrate the internal oscillator of a PIC microcontroller Design by Noureddine Benabadji, University of Sciences and Technology, Oran, Algeria

Circuit controls ratiometric or simultaneous power-up of multiple rails -  13-May-04 EDN-Design Ideas Many applications use FPGAs, ASICs, or DSP chips, which usually require multiple voltage rails, typically two  the core voltage and the I/O voltage.  The core voltage is usually lower than the I/O voltage.  Guidelines for determining how to power up two orvoltage rails depend on the part and the manufacturer you use Design by Dirk Gehrke, Texas Instruments, Freising, Germany

Circuit Converts Between TTL & Shifted ECL -  08/15/96 EDN-Design Ideas The bidirectional circuit in Figure 1 translates TTL to shifted ECL (SECL].  There are currently no IC's available that perform this type of level translation.  SECL levels correspond to either ECL or PECL referenced to a VCC of 2V and a VEE of -2.5V.  You frequently encounter these levels in situations where the outputs of the ECL logic terminate Design by Sylvia Planer and Paul Sofianos, Motorola LICD, Chandler, AZ

Circuit for Measuring Motor Speed Uses Low-Cost Components -  11/08/07  EDN-Design Ideas A microcontroller-based circuit provIdeas both an LCD readout and an analog motor-speed output Design by R García-Gil, J Castelló, and JM Espí, Escola Tècnica Superior d’Enginyeria, University of Valencia, Spain

Circuit forms industrial-grade digital potentiometer -  09/20/01 EDN-Design Ideas Both ac and dc motors in modern industrial systems often receive their control from PLCs (programmable-logic controllers] in a control room safely away from the process.  If an operator must manually set the motor speed while observing the process, the component of choice is usually an industrial-grade potentiometer Design by Phill Leyva, Maxim Integrated Products, Sunnyvale, CA

Circuit forms random-bit-sequence generator -  05/10/01  EDN-Design Ideas A random-bit-sequence generator is basic equipment for prototyping and testing any data-transmission system.  You use such a generator when measuring BER  (bit-error rate) and pattern-dependent effects in a transmission system.  Such effects can include base Design by Przemyslaw Krehlik

Circuit gang-programs EEPROMs over I2C bus -  09/13/01 EDN-Design Ideas You use the fully controlled circuit in Figure 1 to parallel-program two-wire serial EEPROMs via the I2C bus.  Gang programmers must address all memory devices during a write operation.  To verify the memory contents, however, the system must address only one memory at a time during read operations Design by Denisa Stefan, Catalyst Semiconductor, Sunnyvale, CA

Circuit Monitor 2 -  PIC Project  This is a circuit monitoring device.  It runs for over 10 days and can log up to 32k events both digital and analog.  Samples are logged either on a timing basis  (.01 to 2.5 seconds) , or on a triggered basis.  Four inputs are provided, up to three of which can be analog __ Designed by Luhan Monat, Mesa, AZ

Circuit programs Atmel AVR microcontrollers -  30-Mar-00 EDN-Design Ideas Atmel AVR mCs feature an enhanced RISC architecture that purportedly offer the highest MIPS-per-milliwatt capability in the 8-bit mC market.  Figure 1 shows an easy-to-build AVR mC-programming circuit that can program the 40-pin AT90S4414/8515, the 20-pin AT 90S1200/2313,PDF has many circuits, scroll to this one Design by Guo-Yin Xu, XuMicro, Houston, TX

Circuit provides digital hysteresis -  12/03/98 EDN-Design Ideas It is sometimes useful to have hysteresis in a digital circuit—for example, in a power circuit under the control of a manual pulse generator, in which mechanical vibrations can produce position errors.  The circuit in Figure 1, which consists of a 4585 comparator (IC2) , a.   File has several circuits, scroll to this one Design by W Dijkstra, Waalre, The Netherlands

Circuit provides watchdog for microcontrollers -  12/26/02 EDN-Design Ideas The watchdog circuit in Figure 1 uses a single NAND Schmitt-trigger IC.  The circuit iscost-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 Design by VM Holla, Bangalore, India

Circuit transmits ARINC 429 data -  07/11/02 EDN-Design Ideas The ARINC  (Aeronautical Radio Inc] 429 specification defines the air transport industry's hardware and protocol standards for the transfer of digital data between avionics systems.  Circuitry that can implement elements of the 429 sp Design by Steve Woodward, University of North Carolina, Chapel Hill, NC

Clock Controller using AT89C2051 -  The Clock Controller V1.1was designed to be an exemplary of using 'C' language to control timer0interrupt, 7-segment LED and keypad scanning.  It provides 1-bit sink currentdriving output, for driving a relay, opto-TRIAC, say.  Many projects requiring7-segment display and keypad interfacing may get the idea from the Clockcircuit and software.   __ Designed by Wichit Sirichote

Clock with Timer & Solar Panel Regulator -  This is a combination digital clock timer and solar panel charge controller used to maintain a deep cycle battery from a solar panel.  The timer output is used to control a 12 volt load for a 32 minute time interval each day.  Start time is set using 9 dip switches and ends 32 minutes later. __ Designed by Bill Bowden

Closed-Caption Decoder -  This is a closed-caption decoder with serial output based on a Microchip PIC16F628A.  The internal comparators of the PIC16F628A are used to implement a peak detector and data slicer __ Designed by The hardware was Richard Ottosen, and the firmware was Eric Smith

CMOS IC Makes Low-Cost Digital Potentiometer -  01/18/96 EDN-Design Ideas A growing trend in the design of electronic equipment is to replace analog knobs used to increase or reduce a continuous signal  (such as volume or brightness]with "up" and "down" keys.  However, replacing a low-cost analog potentio Design by Jose Carlos Cossio, Santander, Spain

Cockroach Zapper -  Using a PIC for this device provides a lot of useful functionality.  The timing for the power pulse to the inductor is critical to getting the best Zap from your nine volt battery.  The longer the current is on, the higher the voltage.  Once the inductor reaches saturation, however, you are just waisting power.   __ Designed by Luhan Monat-Mesa Arizona

Colour (Sound) Organ -  This is a simple, one lamp colour organ.  It is far less complicated then the Three Channel Colour Organ.  It is simply a lamp controlled by an SCR.  It can be built in a few minutes, and combined with other circuits to make some pretty neat effects.   __ Designed by Aaron Cake

Colour Bar Generator -  I started this project 3 weeks ago, because I was wondering " is that possible, some AVR MCU to create simple colour bars? " At the beginning, I  believed that it's easy.  So, I asked some people who knew more about PAL composite video signal.  The first idea was to work with 8.867238 MHz crystal    (2 times the color carrier) .  When I read about PAL video composite signal creation, I saw that if you want to product colors entire-in-software you must create the color-carrier    (4.43 MHz) , changing 4 times the phase of color-carrier    (one time for each color) , to show 4 colours.  Except that, you have to change the color-burst from 135 deg to 135+90= 225 deg. __ Designed by Vassilis Serasidis; Improved Zdenek Zechovsky

Colour Maximite Microcomputer, Pt.1 -  The original Maximite microcomputer  (March-May 2011) has been a huge hit with readers and thousands are now in use all over the world, from Australia to Russia.  So how do you improve on such a big hit? How about by adding eight vibrant colours and a stereo music synthesiser for a start? The result is stunning and it takes the Maximite to a whole new level.__ SiliconChip

Colour Maximite Microcomputer, Pt.2 -  Building the unit and using its new sound & colour features__ SiliconChip