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4 Band Resistor
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PIC Microcontroller Circuits
PIC Microcontroller Circuits
Microcontroller Based Telephone Remote Control Circuit
This device allows you to control remotely any (with suitable add-on expansion boards, up to eight) device, such as lights, water heaters (boiler), air-condition, plant watering, alarms, etc via a relay. By using it you can for example water the garden at your country house from the convenience of your living-room, or you may turn on the water...
Pic-Plot : a GPIB to RS-232 converter
This adaptor will capture plots or prints of your GPIB instrument to your PC through the serial port. It fills the need of anybody who has a test instrument with the GPIB port and likes to get the screen dump on his PC without any GPIB card. Project based on a PIC16F628A microcontroller.
IR Link PIC tranceiver
I just finished a half duplex serial asynchronous link from a simple PIC circuit to the RCX. It is able to receive codes from the RCX (or Lego RCX remote control) store them in RAM & EEPROM and transmit any IR op-code to the RCX in turn. Included in the firmware is a routine that takes any opcode(s) and expand it to the proper IR packet for...
darkroom timer with PIC 16F84A
I tried to design a timer that would do everything it needed to do but with the smallest number of pieces and simplest mode of operation. It only needs the PIC, a four digit LED display, one other IC, a resistor network, one pushbutton switch and a capacitor. It can run on batteries if you use a solid state relay to turn the exposure light on...
Circuit transmits ARINC 429 data
The physical transmission medium for the 429 standard is 78Ω shielded, twisted-pair cable that uses a complementary, differential bipolar RZ (return-to-zero) waveform (Figure 2). The voltages are the net differentials that the biphase drive develops: For example, the differential is 10V when you drive the Data A signal in Figure 1 to 5V and the...
The WWVB signal is broadcast as a 60 kHz carrier that is AM modulated with a time code frame that is updated once per minute. The data rate is one bit per second. Along with time code information, the data frame also contains synchronization bits, calendar data, UT1 correction, leap year, and leap second data. The clock design presented here...
Voltage Ampere and Temperature meter with PIC16F877A
This project was designed and constructed as enhancement to the 0-30V Stabilized Power Supply Project with the DIY electronics hobbyist in mind. The circuit uses a single PIC Microchip to perform the Voltage, Current and Temperature conversions and display functions. The PCB Board uses large tracks and can easily be made using the "press-n-peel"...
testing Board for PIC12F683
This microcontroller fascinated me a lot because I wanted to see what we can do with an 8-pin microcontroller (out of which 2 pins goes to power supply, so actually just 6-pins are left for I/O). So I thought of making my own learning board for this. In this project, I am first going to describe the learning board that I made, and then will...
Servo pulse to PWM converter
The circuit presented on this page attemps to be an interface to convert pulses such as provided by a Basic Stamp or R/C receiver to a dual PWM(Pulse Width Modulation) signal required by an H-bridge. The simplest circuit would use a small microcontroller like a PIC. This circuit takes a more traditional approach. Many experimenters will have all...
CMOS hex inverter generates low-distortion sine waves
This Design Idea provides a simple, inexpensive, portable circuit as an alternative to a microcontroller to provide a wide-range source of low-distortion sine waves for audio-circuit design and debugging. Although sine waves from DDS (direct digital synthesis) offer greater stability and fewer harmonics and other spurious-frequency components,...
PIC debugging routine reads out binary numbers
The "burn and learn" method of firmware development excludes an in-circuit emulator and a serial port. With this method, it is common practice to use spare I/O pins on a µC as a debugging aid. By strategically placing instructions to set and clear these I/O pins in the code and then observing the pins with a scope, you can obtain limited...
PIC Based RS485 Multiplexer
I decided to implement this using a PIC 16F84 for both an encoder and decoder, and use RS-485 drivers (DS26C31 and DS26C32) to drive the 350m cable. I only needed five I/O pins per PIC, so this could have been implemented using the smaller 8pin 12C508 device, but the 16F84 has the advantage of being reprogrammable, and PCB size or cost wasn`t an...
Classic PIC Programmer
This is my own version of the classic PIC 16C84/16F84 programmer. The design is originally by David Tait. I`ve made a few changes, redrawn the schematic and done a board layout. All the files you will need are linked below, including software you`ll need to operate it. The software is not by me, I`m just including it for your convenience, and...
PIC Project #1 - RS232 to I2C Interface
The software sample is written in C for a specific application. A general purpose interface is not available at this time but is planned for the future. The information detailed here should provide the basic framework for designing and implementing your I2C application quickly and efficiently.
Infra/radio remote control transmitter/receiver with PIC
This is a general purpose remote control project with using programmable PIC microcontrollers. Schematics are shown for using infrared (RF) or radio (RF) media. If you are not familiar with microcontroller programming, you can use fixed encoder and decoder integrated circuits instead. Well-known such IC-s are Holtek HT-12D, HT-12E and Motorola...
PIC Tone generator
This program uses an 8 bit DAC along with a 16F84 PIC microcontroller to generate a keyed sine wave. The 16F84 uses an RC clock which can be varied (with a suitable potentiometer) to allow a variable frequency control for the sine wave output. A key or keyer output can be connected to pin 1 of the PIC to control the tone output.
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...
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,...
Programmer PIC16F84,12C50x and EEPROM 24Cxx
Programming is very straight-forward when this programmer is used in conjunction with the easy to use DOS-compatible software. No requied power supply.
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...
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,...
Comparison macro for PIC processors
If you ever get tired of trying to remember the subtleties of the "carry" status bit every time you want to use the subtract instruction to perform a comparison, the macro in Listing 1 can help. The macro contains all of the nuances, once and forever. The macro reads like a sentence: branch to target if ram-register is [comparison condition] a...
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...
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...
Make noise with a PIC
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. A single...
This is a new design of a tutorial board based on the popular PIC16F84A microcontroller. It features eight single leds, a 7-segment display, an LCD display and five push buttons. It is an ideal solution for the beginner to take his/her first programming steps in the world of microcontrollers. Having an in-circuit-programming (ICP) header, it can...
12F675 as a D-type or JK-type flip flop
Since I implemented a D type flip flop using the PIC Logic Elements I thought I might go the other way and implement an entire D type flip flop in a single PIC. This uses the edge triggered and port change status interrupts and was an opportunity to have a play with interrupts on the PIC. As written this code will cause a PIC to function as...
PIC Analogue Synthesizer
A real analog synthesizer to build using easy to get components, capable of a wide range of sounds. The two oscillators can be detuned for that classic synth sound. Dual oscillator mono synth. Really easy to build using just 1 custom programmed PIC chip, 4 ICs and single 12v supply. All circuits built on veroboard - no printed circuit board...
This is the lowest cost dialing alarm on the market and shows what can be done with an 8-pin microcontroller. The complete circuit is shown below. You cannot see all the features of this project by looking at the circuit - most of them are contained in the program. So, read on and see what we have included. Dial Alarm-1 has a single input...
Rainbow LED indicates voltage with color
The circuit in Figure 1 comprises IC1, a Microchip PIC12F675 microcontroller driving IC2, a Kingbright AAF5060PBESEEVG "rainbow" indicator that contains three ultrabright LED chips (red, green, and blue) within one package. Modulating each LED`s duty cycle produces all of the perceivable colors of the visible spectrum, including white light....
Digital DALI Ballast for 32W/T8 110V
This reference design is a high efficiency, high power factor, digital dimming electronic ballast designed to drive rapid start fluorescent lamp types. The design contains an active power factor correction circuit for universal voltage input as well as a ballast control circuit using the IR21592. The design also includes a PIC16F628...
GP display controller
This is a simple display controller. It can be controlled with a small microcontroller, such as MCS51, 68HC11, Z80, AVR and others. Several years ago, I found an article that controlling a TV with only a PIC micorcontroller, and I surprised to it. It is very interesting to attempt to synthesize video signal with a micorcontroller. However,...
Arduino Projects and 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...
Digital Signal Integrity
Interconnection and Timing of Digital Circuits
CMOS Circuits Tutorial