In this instructable i will explain how to connect 7 segment display, decoder and arduino. It´s pretty easy. At first we have to learn something about decoder. I´m using BCD to 7 segment decoder. My is D147D, this is old chip, but the newer are similar. Documentation about one of them you can find here . Description of D147D you can see on picture two. There are four pins for sending BCD code to the decoder (ABCD). Table of BCD code you can see on third picture. But there is small problem. I thing, that pins are inside of chip connected to VCC source. If you want set logic zero on input, you must connect this input to the ground. Continue reading Arduino and 7 segment LED display decoder→
The 74xx47 chip is used to drive 7 segment display. You must use the 74xx47 with a common anode 7-segment display (e.g. Kingbright part number SA03). The input to the 74xx47 is a binary number DCBA where D is 8s, C is 4s, B is 2s and A is 1s. The inputs DCBA often come from a binary counter.
The display is only sensible if the binary number is between DCBA=0000 (0) and DCBA=1001 (9); this is called Binary Coded Decimal or BCD for short. If the number is larger than 9 you get a strange output on the display. Try this out by moving your mouse over the truth table. Continue reading Using the 74xx47 BCD to Seven-segment display→
Atmel AVR 8-bits microcontrollers provide pins to take in/output information form/to the outside world in the form of logic values. These pins are usually organised in groups of eight (8) and referred to as a port. The AVR use the alphabet to name these port, example PortA, PortB, etc. The figure below shows the pins of an AVR 8-bit microcontroller which has four (4) digital I/O ports: PortA, PortB, PortC and PortD. The pins of PortA are: PA0 – PA7.
The MQ series of gas sensors use a small heater inside with an electro-chemical sensor. They are sensitive for a range of gasses and are used indoors at room temperature. The output is an analog signal and can be read with an analog input of the Arduino.
The MQ-2 Gas Sensor module is useful for gas leakage detecting in home and industry. It can detect LPG, i-butane, propane, methane ,alcohol, hydrogen and smoke.
This instructable is an origami flower that is lit up using LED’s. In this instructable I show only a flower but you could do many more things. Continue reading LED Origami→
A DC power supply can be hard to find and expensive. With features that are more or less hit or miss for what you need.
In this Instructable, I will show you how to convert a computer power supply into a regular DC power supply with 12, 5 and 3.3 volt outputs. For about $10!
Why use a computer (ATX) power supply? Well, they’re available everywhere, and they can output tremendous amounts of power in a small form factor. They have overload protection built right in, and even a 500W model can be reasonably priced with high efficiency. The voltage rails are incredibly stable. Giving nice, clean DC current even at high loads.
This is a project of mine for my Electronics subject. Well this schematic was a copy from the MAKE Magazine but I found out that there is an error on there schematic so I reconfigure it and this time I use LED Strips which pretty cool. Continue reading Music LED/Color Organ LED Strips without micro-controllers→
We’ve been working with LCD displays, for a long time so we thought we’d show you how to hook up a CFA533 I2C LCD with a Keypad to an Arduino. Giving you the ability to output and control your arduino via I2C. Continue reading Connect Arduino to Crystalfontz CFA533 with I2C→
