Vacuum Tubes Valves
Musical & effects
Yagi Uda Antennas
Metal Detector Circuits
Liquid Sensing Circuits
Light Sensing Circuits
Voltage Detector Circuits
Air-Gas Detection Circuits
Human Sensing Circuits
RF & Radiation
Optical Sensing Circuits
Free Energy Circuits
AC to DC & DC to DC
Solar Cell Circuits
Micro Power Circuits
Switching Power Supplies
Light Laser LED
Digital to Analog
Analog to Digital
Data Bus Circuits
Voltage to Pulse
Current to Voltage
Frequency to Voltage
RF Converter Circuits
Sine to Square Wave
Voltage to Current
voltage to frequency
Period to Voltage
Video Wall circuits
TV Video Circuits
Motor Control Circuits
8051 / 8052
PCB CAD Software
Car bike Circuits
555 Timer Circuits
Remote Control Toy
H Bridge Circuit
DIY HV Variable Cap
DIY PMA alternator
Interconnection & Timing
Digital Signal Integrity
Digital & Bipolars
Sensors & Detectors
Regulated Power Supply
4 Band Resistor
5 Band resistor
6 Band resistor
The microprocessor circuit using a power linear regulator
The microprocessor uses a linear regulator power circuit constructed as shown below, use two MAX666 simply. CPU and A / D converter power supply using A2, RAM and real-time clock power supply with A1. MAX666 output voltage Vo by the VSET (6 feet)
MCU power supply wiring portion
High-precision voltage regulator, isolation transformer with the correct wiring and low-pass filter, to further improve the electrical noise immunity source portion. The wiring in Figure 20-48 and 20-49 as shown in FIG. Figure, chokes (Li, Lz) choose an inner
High Quality Valve Amplifier
In recent years more and more, have a tendency ket demanded higher reimbursement structures with lights and music lovers in general and manufacturers of tube amplifiers. The reason, in their view is that the sound of tubes is more sweet, how rich and incomparably cleaner, On the other hand, however, the entire structure is much more massive than...
Trimming the Internal Clock Generator on the 68HC908KX8 Microcontroller
One of the nicest features of the 8-bit KX8 microcontroller (manufactured by Freescale Semiconductor) is that it includes an internal clock generator (ICG). This allows the chip to run without the trouble and expense of an external crystal or canned oscillator.
Bugdozer is an autonomous mini-Sumo robot. Her main board consists of a MC68HC908GP32 microcontroller along with input/output support chips, a voltage regulator, a crystal oscillator, and the usual assortment of resistors, capacitors, and switches. All chips are socket mounted. I`m not experienced at soldering, so soldering the sockets avoided...
The microcontroller is able to make about 7000 complete line-following decisions per second, which is almost 7 decisions per millimeter when the robot is going full speed. By upping the clock, unrolling loops, and removing my wireless debugging and extraneous code, I could increase the number of decisions per second.
The project consists of 35 LEDs arranged as a 5x7 matrix. This may not seem very impressive but you can display all sorts of effects and treat it like a "window on a large video screen." The project comes with a series of test programs to test the operation of the screen and also the surrounding components. Then we come to the experiments. They...
This was my first sucessful project with a PIC chip. I used a 16F84 with a 10MHz resonator with built in caps. Click here to view the source code to this project. The code is written in Hi-Tech C. Click here to download the source code to this project. File has a ".c" extension.
The JavaBot1 is a small line following robot designed to follow a black line drawn on a dry erase board. It is designed to follow very tight curves. The software still has lot`s of room for improvement but works well as is. The JavaBot1 uses 2 Cirrus CS-70 servos that have been modified for full rotation and have had their controller boards...
Hidden Radio Transmitter Controller
PicCon is a PIC microcontroller based radio controller designed for hidden transmitter hunting. When combined with a radio transmitter, it will produce tone sequences and Morse code messages at user-programmed times. It is completely field programmable via DTMF tones, utilizes EEPROM for all programmed options so they are remembered when power...
PIXpand (beta 0.1)
This is a beta release of the PIXpand project. The PIXpand which is a device that connects to a TI calculator and enable it to store and retreive data to and from Playstation Memory cards. I am making this beta release as I do not have the time to continue with the project right now. Thus I would be grateful if people can build this device and...
Power up a microcontroller with pre-power-down data
It is sometimes necessary to retrieve data at power-up in the same way that they were at the last power-down, so that the product wakes up in the state it had before shutdown or to retrieve some measurement. One approach is to save critical variables into EEPROM or flash memory as soon as they change. This approach is generally not a good idea,...
Program turns PC sound card into a function generator
You can use a low-cost PC sound card as an analog-function generator by controlling the PC with the program "SoundArb." [To obtain SoundArb, download di2409setup.exe, a 1.06-Mbyte self-extracting installation program.] The program generates standard waveforms, noise, and arbitrary waveforms. The program reads arbitrary waveforms from simple...
Rolling-code generator uses flash microcontroller
Many security-alarm systems require the use of a random number. A computer program uses this random number to create a sequence of random numbers to prevent unwanted visitors from gaining entry into a protected facility. You can use a "rolling-code generator" to produce random numbers. To implement such a generator, you would typically need a...
Routine automates pattern/sequence detection
Sequence detection is a common operation in many communication and security systems. Some good examples are HDLC-flag identification and signature analysis. As the complexity of the system increases, designing circuitry for sequence detection becomes tedious and laborious. Using the software tool in this Design Idea, you can generate HDL code in...
A serial to parallel converter using the AT89C2051
The example program included with the PG2051 evaluation kit is a basic serial to parallel converter written in 8051 assembler. This is probably a good example of the uses to which an AT89C2051 can be put - it would be hard to get a serial to parallel converter much simpler than the single 20 pin IC in this circuit. The program is meant to serve...
Simple logic analyzer pushes microcontroller to its limit
A simple logic-analyzer design is compatible with all versions of Windows and pushes the PIC 18C252 chip to its speed limit to achieve a 1-MHz sampling rate (Figure 1). The circuit can examine three channels of relatively low-speed logic signals that have infrequent, or sparse, transitions. The analyzer can record only 510 transitions per run,...
Single processor pin controls on/off function
A recent Design Idea prompted me to offer the simpler solution that I used in a recent project (Reference 1). We needed a momentary power switch with processor supervision. This supervision would allow the processor to delay a power-down request from a press of the power switch until all routines exited properly. In addition, in periods of...
Speed C functions for C16x microcontrollers
The Infineon C16x Series of µCs use an internal 16-bit-register architecture. The architecture can also process byte-wide functions. The µC uses byte moves to implement library functions such as memset() or memcopy(). This process makes the library code independent of count values and address values; both may be odd or even. The disadvantage is...
Squeeze extra outputs from a pin-limited microcontroller
Many of today`s designs use low-cost microcontrollers from Freescale and Microchip, but during the last decade, device packages have resorted to ever-smaller footprints featuring as few as eight or even six pins. Although these packages minimize pc-board area, they also reduce the number of available I/O pins and pose problems for designers who...
10 Tricks for the `508A
Most of the ideas in this chapter can be found on the pages of this website, but just in case you want to go over the capabilities of the `508A, we have brought them together. Quite often when you are programming, the first thing you will run out of is output lines. Many projects need lots of drive lines and if you need more than about 8, you...
The Pocket Programmer is a stand alone serial programmer that can program most of the PICmicro®MCU range of microprocessors. (12C6xx, 16Cxxx, 16Fxxx, 18Cxxx) It works from a single 18VDC supply or with 2 X 9 volt batteries. Combine this with 64K of on board EEPROM which can store upto 32 HEX files and you have a truely portable programmer /...
Two gates and a microprocessor form digital PLL
You can use Microchip`s low-cost PIC16F818 microprocessor and a pair of gates to construct a digital PLL that can clean noisy digital signals over a range of 4 to 40 kHz. Featuring programmable lock range, phase differential, and loop gain, the digital-PLL engine and lock detector can extract clock and data information from noisy, short-range...
Use 8051`s power-down mode to the fullest
The 8051 series µCs offer idle and power-down modes, both of which you invoke by setting appropriate control bits from the code. For instance, a 5V, 12-MHz Atmel AT89C2051 consumes approximately 9 mA in active mode, 1.8 mA in idle mode, and only 12 µA in power-down mode. Although power-down savings outperform those of the idle mode by two orders...
Circuit provides 4- to 20-mA loop for microcontrollers
The 4- to 20-mA current loop is ubiquitous in the world of controls in manufacturing plants. Discrete logic, microprocessors, and microcontrollers easily cover the digital portions of control schemes, such as limit switches, pushbuttons, and signal lights. Interfacing a 4- to 20-mA output to a rudimentary microcontroller can be problematic.
Circuit provides watchdog for microcontrollers
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,...
Wisp628 is designed to be used as an in-circuit programmer only, hence no socket is provided for the target chip. `Why use such a limited design`, you might ask, `an ex-circuit programmer with a ZIF socket can do the same things and more!` You are partially right, but consider the way you would use and ex-circuit programmer for development: take...
WLoader - a 16f877 application loader
If the piclist is an any indication the 16f877 seems to be the new favorite hobby microcontroller, a position that used to be occupied by the 16f84/16c84. Compared to is older brethren the 16f877 has much more to offer at around twice the price. As for all Microchip controllers the datasheet (pdf) and the MPLAB assembler IDE are available for...
An 89C2051 CPU 8 driver outputs
This document describes the HSETI PCB. This PCB is a small simple application for the Atmel AT89C2051 microprocessor - a 20 pin 8051 variant, with FLASH (reprogrammable) program memory. The board has just two chips on it, the CPU and a driver/buffer.
Microcontroller or DSP circuit controls on/off function
In many applications, a single on/off button switches the power supply on or off. Usually, the system switches off regardless of the processing function or workload the microcontroller or DSP circuit is currently handling. The small circuit in Figure 1 is intended to make the microcontroller or DSP circuit the master over this on/off function....
Microcontroller provides SRAM battery backup
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...
Microcontroller takes control of comparator
In many µC applications, a signal conditioner modifies an analog input signal from a sensor and passes it to the µC for processing. The last stage of the signal conditioner is always a device that transforms the signal level to a value acceptable for the µC`s input. Usually, it is a comparator. Often, this signal channel is open or closed for...
Arduino Projects and Circuits
PIC Microcontroller Circuits
AVR Microcontroller Circuits
Microcontroller Programmer Circuits
68HC11 Microcontroller Circuits
8051 / 8052 Microcontroller Circuits
Ultrasonic distance finder circuit
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is measured. There are three main categories of distance measurement methods in use: a) By...
Simple Metal detector circuit with CD4030
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to find something potentially valuable, hidden a few centimeters below the soil. So many...
Fully automatic watering circuit for flower pots
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This circuit comes as a solution to this problem. Depending on humidity of the pot at...
Simple deep searching metal detector circuit
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
Sub-Harmonic Bass Converter for Electric Guitars
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound, such as filtering or distortion. Instead, a frequency division system produces outputs...
Echo Depth Sounding Sonar for Boats
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the calibration of the rope. This arrangement still exists in some yachts. The big...
100W HiFi Audio Amplifier Circuit
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
Plant-Pot Water Level Indicator Circuit
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
DIY HV Variable Capacitor
DIY PMA Alternator Plans
Digital Signal Integrity