Multifunctional alarm clock with internet connectivity We continue to go through circuitcellar 2007 16-bit PIC design contest. Next project (second place winner), developed by DJ Delorie, is a cool multifunctional alarm clock that is connected to internet. Along with cool look of this clock it also has several nice features like automatic time setting on power up, can play streaming MP3 music and of course clock can be remotely managed from personal computer that is connected to internet. Alarm clock runs on PIC24FJ64 microcontroller. Internet connectivity is made through ENC28J60 IC. Clock also is equipped with graphical display, volume control and seven buttons for local control. Full project files are here. PIC16F84A Nixie Clock A very compact nixie clock based on PIC16F84A and 74141 driver IC and MPSA92 high voltage transistors. A DCF77 Clock with RS232 Interface The clock is synchronised via the German time signal DCF77. It has a display with automatic brightness control and a RS232 computer interface. The clock is built around a PIC16F84 microcontroller from Microchip. I chose this microcontroller since its FLASH memory is easy to program and assembler and programmer software is freely available for GNU/Linux. It has 13 general input/output pins which is just enough to implement all the feature I wanted. Digital Clock This project is a clock that displays the time and date on seven segment led displays.Designed by Perry Andrews. Two buttons are used to set the time and date. The program takes care of changing the date and keeping track of leap years. He recommend all displays are purchased at the same time otherwise a difference in brightness may occur. This page contain documentation, circuit diagram, ‘C’ program and Hex code. LED Desktop Clock This project uses RGB LEDs to create a clock face. Each hand is assigned a colour and as the hands overlap on the face of the clock it mixes the colours. The clock uses a single AA battery to power the display which is boosted to 5 volts with a switching mode power supply. The power supply should be able to use any AA battery that is at 0.7 volts or higher, which means that it should still work fine with AA batteries that may be “dead” when used in other devices. The heart of the clock is a DS1307 realtime clock with a CR2032 coin cell battery backup. The battery should be sufficient to keep the time for at least a couple of years. GPS-based universal clock generator Almost all commercially available GPS OEM modules provide a 1pps output, synchronized with GPS time. This pulse could be used as a reference to generate accurate high-frequency clocks, but special design has to address the short-term jitter affecting the 1pps signal. As a general guideline, an oven-stabilized crystal oscillator who guarantees the short-term stability is synchronized with the GPS 1pps for the long-term accuracy. Real Time Clock Module This a custom designed module for the DS1307 Real Time Clock. The module comes fully assembled and pre-programmed with the current time (ok, so it’s our current time - MST). The included Lithium coin cell battery (CR1225 41mAh) will run the module for a minimum of 9 years (17 years typical) without external 5V power. The DS1307 is accessed via the I2C protocol. We’ve written a test-bed to program the modules. This test-bed code should give you some insight on how to interface the module to any mircocontroller using our example software I2C and BCD routines. Digital Clock with PIC16F84A This is a small ajustable clock, It’s made based on PIC16F84A microchip.The hardware part is very simple because it only uses 74hct238 demultiplexer, 4×7 segments, and some rezistors. The software part is programmed through a device connected to serial port with icprog and made/debuged with MPlab. GPS-based universal clock generator Almost all commercially available GPS OEM modules provide a 1pps output, synchronized with GPS time. This pulse could be used as a reference to generate accurate high-frequency clocks, but special design has to address the short-term jitter affecting the 1pps signal. As a general guideline, an oven-stabilized crystal oscillator who guarantees the short-term stability is synchronized with the GPS 1pps for the long-term accuracy. Nixie Clock The Nixie Clock uses the Make Controller's Ethernet capabilities to go online and check what the time is, via a protocol called NTP (Network Time Protocol). Once it determines the current time, it uses the digital outs on the Make Controller to communicate with a pair of custom circuit boards that drives the nixies and updates the time. Each custom board drives a pair of nixie tubes - they use a few ICs to allow 3 digital outputs from the Make controller to generate the 8 outputs needed for each pair of tubes. So, 4 nixie tubes (2 for hours, 2 for minutes) use 6 digital outputs from the Make controller. |
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