Tag Archives: Alarm

ATmega Alarm Clock & Thermometer Humidity meter


nitram147 @ instructables.com has build a ATmega based alarm clock with temperature and humidity reading. Sensor used is DHT11.

First, let me introduce you my project. I made an Alarm clock with extended functionality & thermometer and humiditymeter. Everything started when my friend (who used to bring me some old electronic rubbish and I used to check if there’s not something useful) brought me some cashing register display similar like that. When I first see them I knew that I will made from it alarm clock.

ATmega Alarm Clock & Thermometer Humidity meter – [Link]

ESP8266 DIY Wifi Smoke Alarm Notifier


simpleiothings.com has build a Wifi connected smoke alarm using ESP8266 module:

This tutorial will teach you how to build a Wifi Smoke Alarm Notifier for about $10 dollars. You won’t have to code anything, and you won’t have to solder or buy expensive electronics equipment. Any services you are asked to use will be 100% free. Its that easy. Lets get started!


One of the reasons why IoT devices can be built so easily now is because of the ESP8266 development board. IoT enthusiasts have been excited about the ESP8266 because its a full system on a chip (SoC) that has onboard wifi connectivity that can cost as low as 3 dollars.

ESP8266 DIY Wifi Smoke Alarm Notifier – [Link]

Anti-Drowsiness Alarm

This reference design is an anti-drowsiness alarm, which aims to keep the drivers alert by disrupting one’s drowse. According to the study by U. S. National Highway Traffic Safety Administration (NHTSA), drowsy driving is the primary contributor of at least 100,000 auto crashes a year. Statistics shows that most crashes caused by drowsy driving occur from midnight to 8:00 am. During these times, a person often goes to sleep since it is dark outside.

The light dependent resistor (LDR) and the transistors (Q2 and Q3) serve as switch that prevents the oscillation of CD4060 binary counter. When the LDR is exposed to light (i.e., daytime), Q3 conducts while Q2 does not. This makes the RESET pin of CD4060 high to prevent it from oscillating. At night, Q3 does not conduct while Q2 conducts and pulls the RESET pin of CD4060 to ground. This starts the oscillations of CD4060 as indicated by the flashing of LED6. The internal oscillator of binary counter CD4060 oscillates at a frequency based on the values of R8, R9 and C3. The sensitivity of the LDR can be adjusted by the potentiometer R12. When the Q13 (pin 3) output of CD4060 becomes high, the RESET pin (pin 4) of the NE555 becomes high and it starts oscillating. Its pulse rate can be slightly adjusted using the potentiometer R6. The pulsed output of NE555 is then fed to the clock input of CD4017. The CD4017 is a decade counter with ten outputs, but only one of its outputs is high at a time and all the other outputs remain low. The output from NE555 serves as clock for CD4017. As a result, the Q1 output of CD4017 becomes high at the first positive edge from NE555 after 50 seconds. After 6 minutes, the Q6 output goes high and LED4 glows for one minute and the warning buzzer sounds. If the circuit is not reset using push-to-switch 1977737-1 after hearing the warning beep from PZ1, the counting of CD4017 continues and at the end of the 10th minute, the Q9 output becomes high to activate CD4093.

This circuit is designed to keep the drivers awake while driving at night. This is done by sounding intermittent beeps and by emitting flashing light. As long as Q9 output of CD4017 remains high, CD4093 oscillates and the piezobuzzer beeps and the white LEDs flash with a frequency determined by the values of R3 and C1.

Anti-Drowsiness Alarm – [Link]

PIC24 bedside table alarm clock


Markus Gritsch posted pictures and code of his PIC24 bedside table alarm clock:

Another year, another clock, but for the first time for my alarm clocks. I am not using an MSP430 but a PIC24 instead. Standby current is with 5.5 µA only slightly higher than that of my MSP430 based ones. Time keeping is done using the RTCC pheripheral, which I also used for the first time.
It can be seen in action in this YouTube video
Friendly green digits :)
And of course it has a LiFePO4 battery on its back, being charged every few years using my new USB charger.
A photo transistor is also included to dim the display in the dark. Much nices to the eyes when checking what time it is in the middle of the night.

PIC24 bedside table alarm clock – [Link]

GSM based SMS Alert Fire Alarm System using Arduino


by jojo @ circuitstoday.com

Recently we have learned how to interface GSM Module with Arduino and send/receive SMS using GSM module. Interfacing any device with a micro controller is the first step to building a useful system or project with that particular device. In this tutorial, we are going to build a very interesting project – a Fire Alarm System which will send SMS to a set of Mobile Numbers when fire occurs in a particular location. We have seen many typical Fire Alarm projects which will alert with a siren or an automatic shutdown mechanism. This fire alarm project make use of modern communication technologies to deal with emergencies.

GSM based SMS Alert Fire Alarm System using Arduino – [Link]

Arduino Laser Trip Wire


by ronnietucker @ instructables.com:

So, first thing I did was to get the LCD and keypad working together.

For this I pretended that it was some sort of arm/disarm (or entry/exit) thing.

My code for this part is at: http://pastebin.com/YndLneqm.

Getting the LCD wired up was tricky as most wiring diagrams for it don’t show the last two pins wired up and these are required for the back light. Check my snazzy Fritzing wiring diagram to see how I wired up my LCD screen, pot (for adjusting brightness) and keypad. The pins for them all are also mentioned in my code.

Arduino Laser Trip Wire – [Link]

Bag movement alarm for theft prevention


by micahmelnyk @ instructables.com:

In short: I developed a portable, battery powered device that sounds an alarm when your bag or purse is moved. Once armed, can only be turned off by your secret code.

The device is built off an Arduino compatible Trinket Pro, using an off-the-shelf project box with PCB.

Bag movement alarm for theft prevention – [Link]

LED display Over Temperature Alarm


by Joe @ hobbyelectronics.net:

This project was built to monitor the temperature of one of our computer rooms at work that has rather temperamental air-conditioning. The maximum temperature can be set, and if this is exceeded an alarm is activated.The unit gives a continuous display of current temperature and it’s possible for the constructor to change the device program firmware or display board.

LED display Over Temperature Alarm – [Link]

Website Down Alarm using Tessel board


This is a website down alarm using a Tessel module. Check it on projects.tessel.io:

If your website goes down, you want to be the first to know. Make it obvious when there’s a problem by hooking up a big alarm light to a Tessel, which will ping your website every few seconds to check for trouble.

Continuously off: all is well
Continuously on: website being monitored is down
Two-second bursts (on or off): system error; monitoring isn’t working (reset the Tessel)

Website Down Alarm using Tessel board – [Link]

Frozen Pipe Alarm


by DIY Hacks and How Tos @ instructables.com:

Winter is coming. So it is time to make preparations. If you live in a colder climate, you need to be concerned about the possibility of your pipes freezing. There are a lot of preventative measures that you can take such as insulating your pipes and leaving the water dripping. But for a little extra peace of mind, I designed a simple alarm that will notify me if the pipes are getting too cold and are in danger of freezing.

Frozen Pipe Alarm – [Link]