Timer category

2 Digit Kitchen Timer 00-99 Seconds or 00-99 Minutes

The projects shown here is a 2 Digit 00-99 Seconds or 00-99 Minutes Countdown kitchen timer based on PIC16F1825 micro-controller. The timer is useful in various applications like Cooking, Sports, Industrial, Sleeping. On board switches provided to set the time and start, a jumper to select the mode 99 Seconds or 99 Minutes. TTL output directly drives the Buzzer.

Features

  • Supply 5V DC
  • Timer 0-99 Seconds Or 0-99 Minutes
  • On Board Power LED
  • On Board Output LED
  • Jumper J1 Mode Selection Open Seconds, Closed Minutes
  • 2 Digit 0.5Inch 7 Segment Display
  • Tact Switch for Time Set & Start
  • Output 5V TTL Direct Drive Buzzer

2 Digit Kitchen Timer 00-99 Seconds or 00-99 Minutes – [Link]

$18 RTC Shield For Both Arduino UNO And Raspberry Pi 3

Time and date information may be essential requirements for developing a hardware project, such as registration systems, alarms, and smart pills box. These information can be obtained locally by RTC (Real Time Clock) and RTCC (Real Time Clock Calendar) circuits like DS1307 from Maxim Integrated.

Microchip, an embedded control solutions company, produced MCP7941X three-member family of low power RTCCs with EEPROM and SRAM. Each of MCP79411 and MCP79412 has a unique MAC address that can be programmed by the end user for the networking applications. MCP79411 uses 48-bit MAC address and MCP79412 uses 64-bit one. MCP79410 is suitable for non-network applications as it has the same features except the unique ID.

These integrated circuits are compatible with I2C™, include a battery switchover circuit for backup power, and use a low-cost 32.768 kHz crystal, providing time tracking in 12 or 24 hour format and two settable alarms to the second, minute, hour, day of the week, date or month. They also have programmable output pin which can be set as an alarm out or a selected frequency clock out.

MCP79410 Integrated Circuit
MCP79410 Integrated Circuit

MCP79410 has the following features:

  • Battery-Backed Real-Time Clock/Calendar (RTCC) with configuration of Hours, Minutes, Seconds, Day of Week, Day, Month, Year in 12/24 hour modes
  • Leap year compensated  to 2399
  • On-Chip Digital Trimming/Calibration with 1 PPM resolution and ±129 PPM range
  • Dual programmable alarms
  • Versatile output pin
    • Clock output with selectable frequency
    • Alarm output
    • General Purpose output
  • Power-Fail Time-Stamp, time logged on switchover to and from Battery Backup
  • 2-Wire serial interface, I2C™ compatible, clock frequency up to 400 kHz
  • 64 bytes battery-backed SRAM and 1Kb EEPROM memory user memory
  • 64-bit protected EEPROM area, robust write unlock sequence
  • Wide voltage range, operating voltage 1.8V to 5.5V and backup voltage 1.3V to 5.5V
  • Low Typical Timekeeping Current
  • Automatic Switchover to Battery Backup
MCP79410 Box Diagram
MCP79410 Box Diagram

Based on MCP79410, Futura Group Srl developed a RTC shield compatible with Arduino UNO and Raspberry Pi 3 Model B and it supports all of the functions needed to manage the MCP79410 circuit.

The shield PCB contains the MCP79410 chip, SMD components, CR2032 battery holder, male and female stripps, and three buttons. The three buttons are connected with the Arduino and Raspberry Pi and they are used for the configuration process.

The RTC Shield
The RTC Shield

There is also a library which allows you to use and program the shield easily. It contains three files, two of them are the functions and theirs declarations, and the third is a text file contains the keywords of public functions and theirs usage.

The shield is available for $18.5 (16.50€). You can order it from open-electronics store and have access to the libraries and example sketches.

Full documentation of the shield with its schematics and diagrams is available here.

Rubidium Disciplined Atomic Clock

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Cameron Meredith build a real-time-clock module controlled by a rubidium frequency standard, and since it also includes a GPS clock he can track local time dilation effects by comparing the two.

An I2C multiplexer board allows for more than one RTC module (Since these have a hard coded I2C address you can normally only use one). I went for three – One tracking GPS time, another tracking the rubidium standard, and the last one as a control or reference clock – without compensation.

An arduino knock-off compares the relative delay between the pulse-per-second outputs from the Rubidium standard, Real Time Clocks, and GPS.

After some defined time divergence, the RTC aging compensation register is updated to refine or maintain overall agreement. Essentially herding the RTCs so that their output stays within bounded agreement with the Rubidium standard and GPS.

Rubidium Disciplined Atomic Clock – [Link]

Chip-scale atomic clocks bring accuracy and stability to portable applications

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Microsemi released a chip scale atomic clock reference bringing stability and accuracy to portable devices.

The Microsemi Quantum™ SA.45s CSAC is the world’s first commercially available chip scale atomic clock, providing the accuracy and stability of atomic clock technology while achieving true breakthroughs in reduced size, weight and power consumption.

The Quantum SA.45s CSAC produces two outputs, a 10MHz square wave and 1PPS, both in a CMOS 0V to 3.3V format. It also accepts a 1PPS input for synchronization and provides an RS-232 interface for monitoring and control.

Chip-scale atomic clocks bring accuracy and stability to portable applications – [Link]

Count down timer for UV lamps using PIC16F887

Piccounter

Here is a countdown timer for UV exposure lamps @ cuteminds.com

Here follows a simple count down timer useful for the production of pcbs using photoresist and UV lamps. We have used a pic 16F887 Microchip microcontroller; there are no particular reasons, we have simply used the picmicros available at the moment.

Count down timer for UV lamps using PIC16F887 – [Link]

ESP8266 Desktop Clock – WiFi Synchronised

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This project is a wifi synchronised desktop clock using 7-segment displays. The heart of the project is a ESP8266 board.

The ESP8266 is a awesome chip; with integrated WiFi, 80MHz clock speed, total 160kb RAM, 512kb of flash memory, and a ton of other features, it makes a regular Arduino look like a joke. The project shown in this Instructable is based solely on the ESP8266-01 module, unlike several other projects on the web where it is used in tandem with another microcontroller. This makes it great demonstration of the capabilities of the ESP chip.

ESP8266 Desktop Clock – WiFi Synchronised – [Link]

Ultra Low-Power (35nA!) Programmable Timer using TI TPL5111

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Ultra Low-Power (35nA!) Programmable Timer using TI TPL5111.

Imagine a system for example that has to work from a small coin cell for 5-10 years.

TPL5111 solves a typical problem in low power wireless systems- things need to be off most of the time, and wake up periodically to transmit.

Ultra Low-Power (35nA!) Programmable Timer using TI TPL5111 – [Link]

T-baneklokke – A Coundown clock

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Joakim made a coundown clock for his wife and documented the whole process on his blog:

The clock is built using an Arduino, and has a battery powered real time clock to remember the time while powered off.
To make it truly stand alone I added the possibility to set the time and time-to-leave using buttons.
The clock was built into a custom made plexiglass box, and the outside covered with a design printed onto photo paper with a sticky back side. I used my wife’s Cameo vinyl cutter printer to cut the paper – I just love that machine!

T-baneklokke – A Coundown clock – [Link]

Fluke/Philips PM66xx Frequency Counter OCXO Upgrade

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In this post Dan Watson documents an OCXO upgrade board he designed for the Fluke/Philips PM66xx line of frequency counters.

A few months ago I purchased a Philips PM6674 frequency counter on eBay. It’s an older 9 digit counter with two channels that has a maximum input frequency of 550MHz. The design feels dated compared to more modern counters, such as my Agilent 53131A.

Fluke/Philips PM66xx Frequency Counter OCXO Upgrade – [Link]

DS1307 RTC Module

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The module based on DS1307, The DS1307 serial real-time clock (RTC) is a low-power, full binary-coded decimal (BCD) clock/calendar plus 56 bytes of NV SRAM. Address and data are transferred serially through an I²C, bidirectional bus. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with AM/PM indicator. The DS1307 has a built-in power-sense circuit that detects power failures and automatically switches to the backup supply. Timekeeping operation continues while the part operates from the backup supply.

Specifications

  • Supply 5V DC
  • Completely Manages All Timekeeping Functions
  • Real-Time Clock Counts Seconds, Minutes, Hours, Date of the Month, Month, Day of the Week, and Year with Leap-Year Compensation Valid Up to 2100
  • 56-Byte, Battery-Backed, General-Purpose RAM with Unlimited Writes
  • Programmable Square-Wave Output Signal
  • Simple Serial Port Interfaces to Most Microcontrollers

DS1307 RTC Module – [Link]