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This is my electronic combination lock to use with an outdoor gate. The functionality is implemented in software. It turns on a relay (usually to open a door) for a few seconds if someone enters the valid code. This relay can operate a power-to-open type electric strike with a shorting contact or a power-to-hold type electromagnetic lock with a breaking contact (we need the relay because these locks usually work with AC, not DC). The code can be changed any time after entering the current code.

Back in 1995 I designed a Mk2 EPROM Programmer, but EA didn't want to publish it. I'm making all of the details available here for those that wish to make it themselves. The schematics, PCB, control program, and PLD files are available here for general interest only, they are still copyrighted to me. This design is NOT in the public domain.

Few years ago we control the lights in the garden with a automatic-timer-switch, very nice but when the evening gets longer or shorter we had to adapt the timer each week. In that time I came in contact with programming microprocessors so my first project was born. The first garden timer was a simple 1 output. The timing was controlled by the PIC and every month I had to change the minutes. So back to the table and design the second garden timer able to control 3 relays - left, mid and right side of the garden. It provided also 4 modes: – always off – always on – from dusk to dawn – from dusk to timer and the timing was dedicated to a RTC DS1307.

Circuit is very simple. The generator uses a PIC12F629 microcontroller with clock frequency set by an external RC. Output frequency can be set trimmer P1 in the range of about 2 to 170 Hz. Oscillator frequency can be adjusted if you change C1 capacitance. Pulses are generated with a period of 200 Tcy. All pulses are of equal length. Output frequency is 800 times lower than the frequency of the oscillator.

All remote controlled projects from this site can be controlled with remote controls which use the RC5 protocol, like the TV-remotes from Philips. When all buttons from such a remote are in use then you could make a remote control by yourself. Your own build remote control with only one button or maybe you want to build a remote with more then hundred buttons. It is possible, however, you need the PIC Basic compiler from Crownhill seeing that everyone has his own wishes and you have to fill in which button sends which RC5 code.

Allows to program PIC16F84, PIC16F628, PIC16F877, etc..

The JDM (or Ludipipo) seems to be among the most popular PIC programmers used - and rightly so: it is simple, cheap and easy to build, can be run with the free and excellent IC Prog software by Bonny Gijzen, and will program pretty much any PIC microcontroller on the market. However, an issue has arisen lately with some of the new PIC's, eg PIC12F675, 12F629, and some others with an internal oscillator. When these chips are programmed the first time, everything goes fine. However, if you later try to read or re-write to them, they read as blank and cannot be written to. The problem only occurs when the PIC has been programmed for INTOSC and MCLR_OFF, but even in this situation sometimes it will re-program OK - there seems to be some other dependence on the program which has been loaded as well.

This is a simple serial based JDM2 PIC Programmer for programming PIC18F chips. The Programmer is powered by the RS-232 port and it works with RS-232 levels at only < ±8.6V. It programs PIC12C5XX, 12C67X, 24CXX, 16C55X, 16C61, 16C62X, 16C71, 16C71X, 16C8X, 16F8X and ISO-CARD's with ASF. The high Vpp is obtained by using negative voltage to drive the chip. The voltage is stabilized with zener diodes. They do not need voltage drop as if a voltage regulator, or has much offset current. This makes it possible to use extra low input voltage. Transistor driver guarantee output level > ±3V. The programmer is supported by PICPgm and WinPic programming software.

Calculates and displays L and C from oscillation frequency using reference components. This instrument requires two precision components: A precision capacitor and a precision inductor. You only need to start with one precision component, either the reference capacitor or the reference inductor, and using this meter, you can select or adjust the other precision component. In my case, I used a pretty high accuracy BK Precision inductance/capacitance meter and sorted through piles of inductors and capacitors to find those that had the lowest error. I then used those parts, a 1 millihenry inductor and a 0.01 microfarad capacitor, in this meter. The basis of this project is several similar projects on the world wide web and some magazine articles before the world wide web was a common means of information interchange. Unfortunately, I am not able to determine the originator(s) of the concept, but I suspect that it is as old as radio. Another project on my web site, LC Determination by Resonant Frequency Measurement, measures the resonant frequency of an L/C circuit, but the hardware stops at the frequency measurement. It does not proceed to calculate the unknown inductance or capacitance.

The LCD Terminal just like a normal terminal, it can connect to any host via RS-232 serial cable. A PC keyboard must connect to it as the input device and what ever you type will send to host via RS-232 and display on a 40x4 LCD. Data receive from host can also display on the LCD unit. You can use this device as any Unix/Linux machine's console.