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22 Oct 2010

This project describes how to make a digital voltmeter using a PIC microcontroller. A HD44780 based character LCD is used to display the measured voltage. The PIC microconotroller used in this project is PIC16F688 that has 12 I/O pins out of which 8 can serve as analog input channels for the in-built 10-bit ADC. The voltage to be measured is fed to one of the 8 analog channels. The reference voltage for AD conversion is chosen to be the supply voltage Vdd (+5 V). A resistor divider network is used at the input end to map the range of input voltage to the ADC input voltage range (0-5 V). The technique is demonstrated for input voltage ranging from 0-20 V, but it can be extended further with proper selection of resistors and doing the math described below.

PIC16F688 Digital Voltmeter - [Link]

5 Oct 2010

This is a digital voltmeter project that uses PIC12F683 to measure the input voltage and displays it on LCD. It uses a resistor divider network to measure input voltage ranging from 0-20V. Full 10-bit resolution is used for internal ADC for higher accuracy. The firmware is written in mikroC and available for free.

0-20V Digital Voltmeter using PIC12F683 - [Link]

1 Sep 2010

This is an easy to build, but nevertheless very accurate and useful digital voltmeter. It has been designed as a panel meter and can be used in DC power supplies or anywhere else it is necessary to have an accurate indication of the voltage present. The circuit employs the ADC (Analogue to Digital Converter) I.C. CL7107 made by INTERSIL.

Led display digital Voltmeter – [Link]

28 Aug 2010

This project is a 3 digit – digital voltmeter based on PIC16F676. PIC is reading the analog voltage using internal 10-bits ADC and display the value on 3-digits 7-segment displays. Check project details on the link below.

3 digits Digital volt meter – [Link]

27 Dec 2009

Ever find yourself in need of some extra ADC capabilities? Maybe you have a micro with no ADC built in, maybe you’ve used up all your ADC pins already, or maybe the integrated ADC doesn’t provide a high enough resolution. This is where a custom-built Capacitor ADC can become very useful.

Low-cost ADC using only Digital I/O - [Link]

2 Nov 2009


Sebastian built an experimental record/looper circuit, resulting in some interesting sample contortionism. [via]

This circuit currently has a few ways to manipulate audio. These are:

  • A record button allows the user to sample incoming audio to a RAM buffer
  • A potentiometer sets the input level
  • A potentiometer sets the sample rate / pitch for playback. The changing of sample rate can be recorded if desired, by physically changing the position of the pot during recording.
  • The address lines A0 – A18 can be manipulated ie. moved around, removed, replaced, giving a wide range of effects such as stuttering, repeating and basic granulation.
    Although this does not sound like heaps of manipulation, keep in mind that this circuit can absolutely mangle a sound beyond recognition. The ADC is running at its maximum speed, and as such the sample rate can be varied greatly for example.
  • Audio looping & manipulation in RAM - [Link]

    17 Sep 2008

    One day while doing some research on something or another on the Web, I came across a link explaining how to connect a MicroChip PIC to a Nokia Cell Phone LCD Screen. Sounded cool; I had been playing with PIC’s and PicAxe’s anyway and thought it was knowledge that would be useful someday. Then I found a Nokia 5165 Cell Phone at an Electronics Flea Market (http://www.FrostFest.com) for $1.00, and at that price, I couldn’t pass it up! I knew I could hook the LCD up, but wasn’t exactly sure what I was going to do with it, when one day it struck me… PIC’s have an Analog Input (ADC) – I could make a very simple, little Oscilloscope! A “Minimalist Oscilloscope” – and thus The Minimalist Oscilloscope 08M Project was born.

    The Minimalist Oscilloscope 08M Project - [Link]

    29 May 2008

    Interfacing an Analog-to-Digital Converter (ADC) with Linux via the parallel port is fairly simple. There two major areas that need to be addressed – hardware and software. The hardware consists of the parallel port, an ADC, and an analog signal source. The software programmed in ‘C’ language. [via]

    Interfacing Your Computer to an ADC via the Parallel Port - [Link]

    4 May 2008

    This robot control by PIC16F818 which has a lot of features that work well in this situation. As you can see from the Schematic and Source Listing, position pulses for the 2 servos are generated dirctly from the PIC. Also, the room light level, battery condition, and servo power draw (indicating mechanical loading) can be measured with the internal ADC. [via]

    Beam Robot - [Link]

    28 Apr 2008

    This simple four channel temperature meter can be connected directly to your computer COM port and doesn’t require additional power supply. Check you computer back if there are any com ports before you start.

    Temperature meter is based on ATtiny15L microcontroller which has built in ADC. Power for this circuit is taken from com port ER and RS signal lines. High level of these lines is from 6 to 12V and can supply up to 5mA of current. As L series microcontrollers are low power this is more than enough.

    As temperature sensors there are four 103AT thermisters used. They give pretty good precision at room temperature (~0.3Cº). Author provides firmware for ATtiny15L and VBA project that logs temperature data to excel file. [via]

    COM port powered temperature meter - [Link]





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