Tag Archives: Led

Temperature Controlled Fan With LED Status

This is a simple fan controller with single LED temperature status light using an ATtiny85 microcontroller and DS18B20 temperature sensor. The fan is turned on/off based on temperature sensed and the controller goes in sleep mode when the temperature drop below a predefined threshold.

Simple ATtiny85 fan controller to turn a fan on/off based on temperature. Includes an LED as a temperature indicator. LED is dim at start of fan on temperature and blinks when above a max temperature. Fan is not PWM controlled since I am using a small 5V fan which is quiet running at 100%. The controller is in sleep state while the temperature is below the minimum threshold and wakes up every ~8 seconds to recheck the temperature. When temperature is above minimum threshold, the controller will stay awake checking every second till the temperature falls below the minimum threshold. The code uses ds18b20 library by Davide Gironi.

Temperature Controlled Fan With LED Status – [Link]

Sound Activated LED Light With Timer

Clap to light switch with timer project is very useful project for power saving applications. The project switches on the LED light for 45 to 60 seconds when receives two clap sound. This project can be used in store room, toilets, dark area where switch is not visible, night lamp, places where light on off switch is not accessible easily.

Single transistor used as microphone preamplifier, diode converts AC signal in to DC , and PIC micro-controller take care of LED On/OFF Time, LED  time depends on two jumpers J1, J2 which provides four options s 45, 50, 55, 60 seconds. MJE3055 transistor used in output to drive LED, one series resistor R10 helps to control the current going through LED, R10 can be alter as per LED Voltage and current. 3V to 12V LED with maximum current 500mA can be used. Use higher current Darlington transistor like TIP147 for higher current Load. Onboard potentiometer trimmer for sound sensitivity adjust. D1 power LED.

Sound Activated LED Light With Timer – [Link]

PICTIL – Remake of the TIL311 hex LED display

Yann Guidon @ hackaday.io rebuild the TIL311 hexadecimal display using a pic microcontroller. He writes:

The TIL311 is a nice but expensive, obsolete, power-hungry hexadecimal display. It would be cool to make a tiny module with similar functionality which solves its shortcomings. A 20-pins PIC is a solution but other decoding chips could work too. The PIC16F527 is one of the cheapest 20-pins PICs (sub-dollar), but it can’t implement the latch pin as fast as the original TIL311.

PICTIL – Remake of the TIL311 hex LED display – [Link]

Programmable LED dimmer

A Programmable LED dimmer from Soldernerd:

Around one and a half years ago I’ve designed and built various LED dimmers for both white and RGB LEDs. Then late last year someone approached me asking if I could make an RGB dimmer for him, too. But my designs were really tailored to their specific applications and built with home-made, i.e. milled PCBs which are time-consuming to make. So I decided to make a more universal version based on a proper, etched board which could be built in a small series and used for all kind of applications, both white and RGB. The result is this versatile, programmable 4-channel dimmer.

Programmable LED dimmer – [Link]

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Multi-brightness LED controller draws zero off-current

T A Babu @ edn.com has a design idea of a led controller with some nice features:

The key features of this Design Idea are:

Soft switch on/off operation

Zero current drain in sleep mode

Two level dimming

Low battery protection

Simple controller based on CMOS 4017 Johnson counter

Multi-brightness LED controller draws zero off-current – [Link]

LED Based Strobe For Entertainment, Events & Warning Signals

Strobe provides regular flashes of light. Usually Strobes are designed using Xenon Tubes. Here is LED based simple solution that can be used as strobe for entertainment and events and also as warning signals. Project is based on PIC16F1825 micro-controller with two digit frequency display.

Project provides TTL output signal, frequency 1Hz-25Hz, Tact switches provided to set the frequency.

This project works along with DC Output Solid State Relay

Features

  • Supply 4.5 to 5V DC
  • Frequency 1Hz To 25Hz
  • Easy Interface with Relay Board
  • Easy Interface with Solid State Relay
  • On Board Power LED
  • On Board Output LED
  • Onboard Switch to set the frequency
  • 2X7 Segment 0.5 Inch Display

LED Based Strobe For Entertainment, Events & Warning Signals – [Link]

Ultra-thin, high thermal conductivity substrate integrates ESD protection

Clemens Valens @ elektormagazine.com discuss about a new IC substrate. He writes:

A new, ultra-thin ceramic substrate with an ESD strength of up to 25 kV – more than three times higher than the standard 8 kV of state-of-the-art Zener diodes – also features a high thermal conductivity of 22 W/mK. This is three times better than that of conventional carriers, even though the substrate is significantly slimmer. The new technology is especially well-suited for LED applications where the number and density of LEDs per unit continues to grow.

Ultra-thin, high thermal conductivity substrate integrates ESD protection – [Link]

AS7221, An IoT Smart Lighting Manager

ams AG, a multinational semiconductor manufacturer and provider of high performance sensors and analog ICs, had announced the AS7221, an integrated white-tunable smart lighting manager that can be controlled through its network connection by means of simple text-based commands.

AS7221 Block Diagram

AS7221 is a networking-enabled IoT Smart Lighting Manager with embedded tri-stimulus color sensing for direct CIE color point mapping and control. IoT luminaire control is through a network connection, or by direct connection to 0-10V dimmers, with control outputs that include direct PWM to LED drivers and analog 0-10V to dimming ballasts. A simple text-based Smart Lighting Command Set and serial UART interface, enable easy integration to standard network clients.

Key features of AS7221:

  • Calibrated XYZ tri-stimulus color sensing for direct translation to CIE 1931/1976 standard observer color maps
  • Autonomous color point and lumen output adjustment resulting in automatic spectral and lumen maintenance
  • Simple UART interface for connection to network hardware clients for protocols such as Bluetooth, ZigBee and WiFi
  • Smart Lighting Command Set (SLCS) uses simple text-based commands to control and configure a wide variety of functions
  • Directly interfaces to 0-10V dimmer controls and standard occupancy sensors
  • Built-in PWM generator to dim LED lamps and luminaires
  • 12-bit resolution for precise dimming down to 1%
  • 0-10V analog output for control of conventional dimming ballasts in a current steering design
  • 20-pin LGA package 4.5mm x 4.7mm x 2.5mm with integrated aperture

“The next generation of lighting will be defined by three key characteristics: controllability, adaptation and connected architectures,” said Tom Griffiths, Senior Marketing Manager at ams. “Our new family of smart lighting managers meet those criteria. With this latest entry, we are addressing the luminaire manufacturers’ critical time-to-market challenge for developing and deploying a spectrally tunable luminaire that is cost-effective, accurate, and which smoothly integrates into the Internet of Things”.

The AS7221 is the first extension to ams’s recently announced Cognitive Lighting™ smart lighting manager family. The compact AS7221 will be available in a 5x5mm LGA package, for flexible integration into both luminaires and larger replacement lamps.

There are main domains of AS7221 applications, some of them are:

  • Smart home and smart building
  • Variable CCT general lighting industrial lighting
  • Retail and hospitality lighting with white-color tuning
  • LED tro ers, panel and downlights
  • LED replacement lamps (LED bulbs)
AS7221 Functional Diagram

Pricing for the AS7221 Spectral Tuning IoT Smart Lighting Manager is set at $3.13 in quantities of 10,000 pieces, and is available in production volumes now.

You can find AS7221 datasheet here.

NVSW319A, A New High Power LED By Nichia

Nichia Corporation, the Japanese chemical engineering and manufacturing company, announced the NVSW319A as a new high-power LED that achieves 164 lm/W at 700mA (5,000K).

The 319A is a 3.5×3.5×2.1 mm size LED which is footprint compatible with the old 3.5mm LEDs. The breakdown is specified at 1,050 mA (~3 W). Nichia planned to start the mass production of this LEDs in the end of December 2016 or in the early January 2017.

“The 319A is a production device, i.e. not one shining brightly deep down in a liquid nitrogen vessel or in the minds of a few theorists at MIT.” Nichia say.

A variant with 3000K color temperature is expected to yield 415 lm with a minimum CRI (color rendering index) of 80. This device won’t give you much deep red though as its R9 CRI specification is zero.

Source: elektor

DIY Breathalyzer Using Arduino UNO

Today I am going to discuss how to make a very simple DIY Breathalyzer using Arduino UNO and few external components. Ana Carolina designed this project as an instructable in instructables.com. This is a low-cost project and a useful one too. If you have no idea about what breathalyzer is, let me explain briefly: A breathalyzer is a device for estimating blood alcohol content (BAC) from a breath sample. Check the link given for more information.

Arduino Based Breathalyzer
Arduino Based Breathalyzer

Requirements:

  • Arduino Uno
  • MQ-3 Alcohol Sensor
  • 128×64 LCD (Liquid Crystal Display)
  • 7 × 330 Ohm Resistor
  • 7 × LEDs (1 Red, 2 Yellow, 3 Green and one other color)
  • Jumpers Wires
  • Breadboard
  • Soldering Iron (optional)
  • Solder Wire (optional)

Details:

This project is very simple. Here we are using an array of six LEDs and a 128×64 LCD to display the alcohol level. The presence of alcohol is sensed by an MQ-3 alcohol sensor and then analyzed by an Arduino board. We are using Arduino UNO in this project, but any model can do the job.

Three Green LEDs represent that alcohol level is OK and within the safe limit. Two Yellow LEDs are used to describe that safe limit is going to be reached, and you know it well why the Red LED is there. In fact, those LEDs are used just to give you a quick idea. If you want to know the exact value, the display is there for you.

You can tweak the program and re-calibrate the breathalyzer. But you must remember that breathalyzer doesn’t precisely measure your blood alcohol content, rather it estimates a value from the amount of alcohol in your breath.

Circuit:

Breathalyzer Circuit On Breadboard
Breathalyzer Circuit On Breadboard

You can make the circuit also on PCB or Veroboard. But for the prototyping purpose, the breadboard is the best choice. You can see how straight forward the connections are.

The Code:

Some part of the original code was in Portuguese. So I have translated it into English. Also, the original code shared by the author in instrucatbles.com is a buggy one. So, I recommend you to use my bug-free code instead of the original one.

Please note that you have to download and add the u8glib library in Arduino IDE beforehand. It is very important. You can either download the u8glib v1.14 library for Arduino directly or go to the site and choose what to download.

Follow the given steps to add a .zip library in your sketch: Open IDE and click on Sketch  Include Library  Add .zip Library. Now select the downloaded .zip library file. You needn’t unzip it.

When everything is done, verify and upload the code to Arduino.

Test It:

I must not recommend you to drink alcohol just for testing the breathalyzer. Rather get a towel and spray alcohol on it. Now hold the towel in front of the sensor. Move it back and forth to observe the change in reading. It may take a while for the breathalyzer to stabilize.

Consider watching the video for a better understanding:

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