LC meter is a handy device. Probably any hobbyist can find C meter on their multimeter while L meter is rare feature on common devices. If you feel that you need compact and reliable LC meter then check this one. This is actually slight remake of Phil Rice original LC meter that was designed quite some time ago. But this circuit seems to be time proved and can serve as good reference for new one.

Among changes there is a Li-Ion battery that replaces 9V pack. So this needs a 5V voltage booster and charger circuitry to make it work. Mini USB connector were added to make charging easy. Also there were minor changes made to firmware where recalibration were fixed. Board was placed in to nice box and now looks really pro.

There two aspects of this project that made it really cool, first would be that its programmable you can make your own games and load the code into it – I was thinking of making one that is similar to the brick game, some of you might not remember it but it’s a very famous game back at the 90’s and two it freakin comes with multicolor LEDs!

This project is neatly placed on a small board where the RGB LEDs, the microcontroller, the small coin-like speaker (piezo transducer) and the switches are attached. The brain of this tiny light of wonders is a PIC16F628A which drives the RGB LEDs through bipolar junction transistors. The BJTs are used as buffers so that the LEDs would not draw too much current from the PIC16F628A.

As of now there are only 3 available games but who knows brunoip might add more! Another neat thing about this project is that two of the four push button switches are placed in the sides – giving us the feel of a playstation gamepad but in 8 bits!

Heart rate is one of many important parameters in diagnosis or sports. It is easy to calculate heart rate by sensing wrist or neck pulse. This method isn’t handy at all as it occupies your hand and mind of course. Doctors use other ways to monitor heart rate which is actually a side effect of other measurements like blood oxide level or pressure. It is actually easy to measure heart rate by using simple circuit based on IR sensor.

In this case infrared sensor catches signal reflected from fingertip (different from pulsoxymeter), so no need for clip – it is enough to put a finger on top of detector. Circuit itself consists of two stages – one is a conditioning circuit which detect reflected signal changes and amplifies it to acceptable level for digital circuits. And second part is a PIC16F628A microcontroller based counter and display driver. In my opinion using clip would be more practical as pressing fingertip to sensor doesn’t seem very practical.

You don’t usually see microcontroller projects in a breadboard and I’ll give you one reason why – microcontrollers require some external components that eventually consumes the prototyping space in a breadboard. This is one of the reasons why hobbyists prefers to make/test projects in a custom PCB rather than the good old breadboard.

To remedy the dilemma of prototyping a PCB just to test a microcontroller circuit, R-B had this very fancy idea of making a breadboard module for a microcontroller. The module’s main part is a PIC16F628A, all the external components to make the microcontroller functional is also placed in the board – oscillator crystal, pull up resistor for the MCLR and even the reset button are already in the board. The only pins that sticks out of the module are the I/O pins and the power pins. Now people can verify microcontroller circuits without fabricating a specific board.