Author Archives: R-B

PCF8563 based alarm clock

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This project is about a PCF8563 based alarm clock built by Shawon Shahryiar from MicroArena. The PCF8563 is a CMOS Real-Time Clock (RTC) and calendar optimized for low power consumption. It features a programmable clock output, interrupt output, and a standard I2C bus to communicate with a host MCU. The project uses the PIC16F877A microcontroller for reading time and date from the RTC chip and a standard HD44780 character LCD for displaying it. The date, time, and alarm settings are performed through a keypad matrix, and a piezo buzzer is used to create the alarm sound.

piclock

Circuit diagram of the PCF8563 based alarm clock

clock3

Alarm clock

Following video shows the alarm clock in action.


The clock firmware is developed using CCS PIC C compiler and can be downloaded from here.

Advanced Arduino data logger

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educ8s.tv has posted a video tutorial on building an advanced Arduino data logger that records temperature, humidity, barometric pressure, and ambient light intensity on a micro SD storage card. It uses some easily available sensors, like DHT22, BMP180, and BH1750, for sensing the surrounding environment and the DS3231 RTC module for time-stamping the measurements. The tutorial describes in steps how to setup the complete project on a breadboard. The data logger runs for about 2 weeks using simple AA batteries and the data are stored on the SD card in a .csv file for easy transport to PC for further processing.

Arduino data logger

Arduino data logger

 

MSP430 Launchpad cyclic timer switch

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This MSP430 Launchpad cyclic timer project is written by Shawon Shahryiar from MicroArena and describes a cyclic on/off timer switch with a standard character LCD for displaying the on/off time as well as the state of the switch, and which can be programmed through capacitive touch inputs. The On and Off times can be programmed separately and the timer cycles endlessly through the set times. Shawon uses the TTP224 integrated circuit to implement 4 capacitive touch inputs in the project. The firmware for the project was developed using Energia IDE and can be downloaded from the link at the end of the article.

setup

MSP430 Launchpad cyclic timer setup

TimerSchematics

Timer project schematic

Demo vide showing the cyclic timer in action.

Download OnOff_Timer Firmware

Automated environmental alert system

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DJ‘s Instructable describes an automated environmental alert system consists of four gas sensors to meausure the concentration of methane, propane, carbon monoxide, and smoke in the air and are connected to an Intel Edison for wireless detection and alerting. The entire system runs with a 5V 3A power supply and the sensor data are read through 4-analog input channels of the Intel Edison board. He used an Arduino breakout board for Intel Edison for rapid prototyping of his project.

Environmental alert system

Environmental alert system

An Intel Edison runs the show for the Environmental Alert System. The Edison is mounted on an Arduino breakout board, which makes it easy to read the analog signals from the sensors and potentiometers. The Edison is connected to the 5V rail via a micro usb cable. The Edison has a built-in Wi-Fi radio, which allows it to connect to the internet without the need for any additional hardware. 

The system has four sensors that connect the Edison. Each sensor is directly powered from the 5V rail and has its signal pin connected respectively to A0 through A3 on the Edison breakout board. The sensors also each have a sensitivity adjustment resistor; the MQ-7 has a 10K ohm resistor and the rest each have a 20K resistor. The MQ-2 is a combustible gas sensor (liquified petroleum gas, propane, hydrogen, and methane) that outputs an analog voltage proportional to the concentration from 300 to 10,000 parts per million. The MQ-4 is a methane gas sensor and has a equivalent concentration to voltage response. The MQ-6 is an LPG, isobutane, propane sensor. The MQ-7 is a carbon-monoxide sensor.

Electronic Snellen eye tester

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Snellen chart is the most widely used visual chart across the globe for testing visual acuity. It contains multiple rows of letters that are progressively smaller and is used by an eye doctor to judge patient’s eyesight. Joel Llewelyn, Margot Haas, and Yuchen Liu (three Cornell students) attempted to make an electronic version of Snellen chart that is portable and self-capable of performing the full Snellen eye test at home. The project uses PIC32 microcontroller and a TFT display for showing the letters from the Snellen chart in a progressively smaller font size and the user has to speak over a microphone his guess for the letters. The user’s audio captured by the microphone is amplified using an Opamp circuit and is further digitized for speech processing by the PIC32 microcontroller. Their electronic Snellen eye tester utilizes a speech recognition thread to determine if the user’s guess is correct or not.

Electronic Snellen eye tester

Electronic Snellen eye tester

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