Tag Archives: LCD

Electricity Frequency Meter


This project is about an accurate mains frequency meter that has a bar-graph displaying the relative deviation from nominal frequency. It can work with 50Hz and 60Hz systems.

An article by Dieter Laues in the February 2012 issue of Elektor inspired me to get my soldering iron out. The article described how by measuring the frequency of the mains electricity supply in any socket, the relative load across the entire electricity network could be determined

Electricity Frequency Meter – [Link]

Using Low Cost Hardware to Enhance the User Experience


Ken Boak discuss how to build a graphic user interface using cheap TFT toughscreen displays. This article is about using their lowcost graphics co-processor IC to provide a neat user interface for any low-end microcontroller.

These days, when you can buy a 7″ tablet for $50, there is all the more reason for makers and hackers to want to become more engaged with up to the minute 7″ touchscreen technology for their latest projects. Fortunately, recent developments in hardware have made this both affordable and easy to do – to the point where no project is too small, not have a neat touchscreen interface – and sound too!

Using Low Cost Hardware to Enhance the User Experience – [Link]

BIG Clock Made From Six 3″ 7-Segment LCDs


Pierre Muth build a nice big clock using 3″ 7-segment LCD displays. The clock is driven by a PIC18F87K90 and a few other components are used. He writes:

We need clocks. Once you have passionate activities which absorbs all your attention, if you want to keep contact with the social society surrounding you, it’s crucial to know when we are.

BIG Clock Made From Six 3″ 7-Segment LCDs – [Link]

MAX038 Function generator


Milen @ instructables.com has designed a Function Generator based on the popular MAX038 and is controlled by ATMega328PU. Signal characteristics are displayed on a LCD screen.

The digital features of the function generator were performed by one Atmega328 chip. Its functions are the following:
controls the frequency range selection
controls the signal type (sine, rectangular, triangular, sawtooth)
measures the amplitude of the signal
measures the DC offset
measures the frequency of the signal
measures the THD of the sine signal in the audio range (this still have to be implemented)
displays all this information on a character 16×2 LCD display.

MAX038 Function generator – [Link]

Smart Battery Charger


gfwilliams @ instructables.com has build a smart battery charger that is able to individually charge each battery , automatically discharge them and give you an idea of their capacity. The charger is controlled by an Espruino Pico and results are displayed on a Nokia 5110 LCD display.

If you’re anything like me you’ll end up with a lot of rechargeable batteries, none of which end up being charged properly, and some of which turn out to be completely unusable. It’d be perfect if you had a low-power battery charger that you could leave on all the time, that would charge your batteries individually, automatically discharge them, and give you an idea of their real capacity. That’s what you’ll make in this tutorial!

Smart Battery Charger – [Link]

Arduino Controlled Modular Bench Power Supply


Denis @ envox.hr has designed a great PSU that is reliable, modular, programmable and of course Open source. The power supply is controlled by an Arduino and a touchscreen TFT screen is used to monitor and control it. It comes with a bunch of features you can check on the link below.

The programmable bench power supply project was an attempt to create reliable, modular, open and programmable power supply that can be used for various tasks starting with powering breadboard, charge (or to some extent discharge) batteries of various types and sizes or use as a tool in school/educational and science experiments.

Arduino Controlled Modular Bench Power Supply – [Link]

How to Set Up and Program an LCD Display on an Arduino


circuitbasics.com has a nice tutorial on how to use a common Hitachi HD44780 LCD display on Arduino. Many of the functions available are discussed and shown in examples.

In this tutorial, I will explain how to set up an LCD display on an Arduino, and show you (with examples) all of the functions available to program it. The display I will be using here is a 16×2 LCD display that I bought for under $10 on Amazon. They can be very useful in projects that output data, and will make your project look a lot more interesting.

How to Set Up and Program an LCD Display on an Arduino – [Link]

LED Tester with LCD Display


David @ robotroom.com build a microcontroller based LED tester with LCD display that shows the LED voltage, the current limit in mA, the desired led voltage and the calculated resistor value. The LED tester is based on ATtiny84 mcu which performs all the measurements and calculations and updates the display. Build details on the link below.

The adjustment trimpots are on the end of the tester. The trimpot with the thumb dial is to indicate the target circuit voltage (usually 5 V or 3.3 V). The other trimpot requires a screwdriver, because it controls current, which I usually want to keep at 20 mA.

LED Tester with LCD Display – [Link]

Battery Powered Frequency Meter (0 to 20kHz)

The circuit is a simple digital frequency meter that is made of a frequency-to-voltage converter and an analog-to-digital display converter that can be operatedfrom a single 9-volt battery. The TC7126 ADC generates the voltage required by the TC9400 FVC with internal regulators. The TC7126 is designed to directly drive a 3-1/2 digit, non-multiplexed LCD display so no digital conversion is required.

The input circuit is made up of a current limiting resistor (33kΩ), a DC blocking capacitor (0.01µF), a clamping diode (1N914), and a biasing resistor (1MΩ). The diode acts as a soft clamp to prevent negative going transitions from latching the comparator input and the 33kΩ resistor limits the current during the positive transitions. The gain (VOUT vs. FREQIN) of the TC9400 is determined by the charge-balance capacitor and the integrator feedback resistor (620kΩ) that has been selected for an output of approximately +2V (referenced to ANALOG COMMON) with frequency input of 20kHz. The bias resistor (12kΩ) determined the input threshold of the comparator and has been selected for an input sensitivity range of 250mV to 10V peak-to-peak of a sine or square wave on the input of the FVC.

The TC7126 will have a maximum positive input of about 2V since the input is referenced to ANALOG COMMON that is only 3V below V+. The internal voltage swing of the integrator does not have the same limitation because a positive input results in a negative swing of the integration. A fully charged battery will give a range of about 6V. The integration components (1MΩ and 0.047µF) at pins VBUFF and VIN are selected, in conjunction with the oscillator frequency to have an integrator ramp amplitude of about –3V with a 2V input from the TC9400. The oscillator is set up to run at 48kHz (150kΩ and 50pF) for maximum rejection of stray power-line pickup. This will result in the TC7126 running at three conversions per second.

Battery Powered Frequency Meter (0 to 20kHz) – [Link]

Arduino Distance Meter


Paoson Woodwork @ instructables.com has build an Arduino Based Distance meter using SR-04 Ultrasonic sensors and an LCD display:

This a project I’ve been working for some time now. It is a device that shows in a little LCD display the distance to the nearest object it can find, usually the floor, the ceilling and two walls or columns. So it can be so helpful to hang a picture, a shell, a light point, calculate the area of the entire wall, etc.
The sr04 has a 3mm resolution, so I am only using it in entire centimeters. You can also change it to inches pressing a button but then the resolution is even worse. I am trying to figure out how to get a better resolution, I know it is possible. Needless to say any help will be appreciated.

Arduino Distance Meter – [Link]