PICADC – The Marvelous PIC Based A/D Converter

Do you have any plan for this weekend? If you haven’t got any, then would you mind to spend the day building this marvelous PIC based A/D converter?

Frankly, many home hobbyists have been familiar with the A/D converter, as it’s one of the common electronic devices that being used in most projects!

Let’s cut the long story short! This PICADC is a very simple 12-bit, 8-channel analog to digital converter. It built based on PIC16F84 microcontroller and a MAX190 ADC. It equipped with four additional digital inputs, which can be connected to the PC through the serial interface RS-232.


The PC is responsible to programming the entire sequence of sampled channels and sampling frequency. The maximal sampling frequency has been limited by the data transmission rate.

The PICADC’s analog input voltage is ranged between -2.5V to 2.5V, while its digital inputs might probably be used, just for recording additional digital signals.

Since the device is quite small, you can mount it on a small-sided printed board easily.

If you’re intend to eliminate the external ADC and multiplexer, then you should substitute it with the integrated 12-bit ADC (PIC16C774).

High Accuracy Digital LC Meter

You’re get involved with many projects that require to measure the impedance of a component? You couldn’t find the right tool to help you overcome the hassle? Well, in this case, you might want to create a brand new high accuracy digital LC meter.

Digital LC meter, or it also known as the “LCR” meter, is the electronic test equipment, which normally being used to measure the impedance, such as inductance, capacitance and resistance! The digital LC meter started to gain its popularity over the analog type, due to their high accuracy and high input impedance. Some other features like auto zeroing, auto ranging, auto power off and down mode are making the digital LC meter more powerful than the analog LC meter!


This project is based on the PIC16F628 and PIC16F84 base inductance/capacitance, where the measuring range is from 0 to >0.1 uF for capacitance and 0 to >10mH for inductance. The expected accuracy is in between +/- 1% of reading +/- 0.1pF or +/- 10nH.

An LM311 comparator with positive feedback is being used to make a parallel LC oscillator with digital output. By applying the LM311 onto the project, it can oscillate over a wide range of L and C values continuously!

The Smart Mobile-Controlled Home Automation System

You’re tired of switch on/off the switches in your house day after day, and you’re looking for something that can overcome this hassle? Well, you should feel lucky about it, as you’ve found the permanent solution for the above matter!

This mobile-controlled home automation system allows you to control the on/off state inside your house. It can control up to eight 3A appliances via mobile phone or through the web browser. The system is cheap and it’s very effective for every household.


However, it has a few perquisites, which as:

  • You have to ensure that the internet connection and computer is always situated in “On” condition;
  • You’ll need the PHP enabled Web space and WAP/web enabled phone, if you want to use the mobile control features of the system.

This project uses a PIC16F84 as the programmable chip and it needs some soldering work. However, it’s only a small matter and you can handle it very well!

Although the switches are simply 240vac relays, where it’s insulated in a plastic project box, but you still need to be very careful about it and never ever use the relays while the enclosure is open. For your information, the 240vac can kill you instantly!

The Fun to Play Snake Game!

Most of you here were probably very familiar with the mobile phone’s snake game, isn’t it? If you cannot get enough with the snake game, would you want to build your very own Snake game here?

In order to DIY this snake game, you’ll have to use 256 LEDs and set them all in 16×16 arrays. The game is at the heart of PIC16F84 microcontroller, where it manages the transfer of four register to display the image of the screen. The device “iron Party” is being intended for the presentation of the picture and keypresses for brokering.


The main purpose of this design is to get the snake game to fit in pocket size. Since the PIC16F84 is only a 13 I/O pins, therefore the free-defined image drawing 256 LEDs consignment consisting of display needed some other components. When a full-screen is maneuvering, it only needed six of the I/O pins.

There is still a problem that you must pay attention here. Since PIC16F84 act is available for only 68 bytes of RAM, the optimization of the code is made entirely of memory-use conditions. As a result, the frequency wills decreases the length of worm grows and the large length is already distracting of the snake movement!