This is a 7 segment clock displaying HH:MM:SS using PIC16F84A and 4017 digital IC. Complete source files are included.
PIC16F84A Digital Clock - [Link]
Having obtained a reasonably reliable 10MHz lab reference (see here) I decided to calibrate my Frequency Counter only to find that the stock oscillator provided in the HP 53151A is absolutely terrible – a joke even! I looked around for an “010 High Stability Timebase Option” but they are rare — and if you can find one not installed in a counter they are very expensive – in the few hundred dollars range at least — and buying one from HP is, well, expensive in the extreme. There are many second-hand 10MHz OCXO modules available, these are mostly stripped from old telecommunications, satellite or cellular equipment so they are plentiful and relatively cheap to buy too. I decided to make a clone 010 option board for my counter using a second-hand OCXO bought from e-bay. I designed a PCB to get a professional finish as well as a reliable upgrade for my counter. The main goal was to make an option board that just like the original could be automatically calibrated using the internal software and front panel controls so I had to use the same DAC chip (which is now obsolete) and basic topology of the original option board to make it work.
DIY HP/Agilent 53131A 010 High Stability Timebase Option - [Link]
This is a collection of Maxim’s newest real-time clock ICs.
This real-time clock IC operates with very low current and is compatible with high-ESR crystals for a space saving, low-cost design. Read the rest of this entry »
The TS3004 is a single-supply, timer IC fully specified to operate over a supply voltage range of 1.55V to 5.25V while consuming 1.9μA supply current. Requiring only a resistor to set the base output frequency (or output period) at 25kHz (or 40µs) with a 50% duty cycle, the TS3004 timer/oscillator is compact, easy-to-use, and versatile. Optimized for ultra-long life, low frequency, battery-powered/portable applications, the TS3004 joins the TS3001, TS3002, TS3003, TS3005, and TS3006 in Touchstone’s CMOS timer family.
TS3004: A 1.55V TO 5.25V, 1.9µA, 0.005Hz TO 300kHz RESISTOR-TUNABLE TIMER IC - [Link]
Kevin Rye posted his Mini 7-segment clock:
I finally got in my OSH Park PCBs for my mini 7-segment clock. It’s using the DP5050 PCB layout. I used the SparkFun 7-seg display, but unfortunately, they screwed up the pinouts on the footprint and pins 10 and 12 are pin-swapped. I had to jumper the pins on the back to get the colon to work.
Mini 7-segment clock project - [Link]
Kevin Rye built this E-Paper clock and wrote a detailed explanation on his blog describing the build:
I still have to put the finishing touches on the code. Instead of having the display constantly update, I’d like to set an alarm on the DS3231 RTC to go off once a minute, and only update the display on alarm. Hopefully I’ll save some battery power that way. As of now, the battery only lasts a couple of days. I built in a USB battery charger to make it easier to charge it. I got my PCBs in from OSHPark and put it all together in an 80mm x 80mm Sick of Beige case. Check it out!
E-Paper clock in a Sick of Beige case - [Link]
The Vetinari Clock comes as an easy to solder kit with everything you need to create your own analog clock that ticks randomly, but still keeps accurate time! The kit comes with a small PCB and all required parts, that you will solder. Also included is a medium-sized wall clock, that you will disassemble and modify, and then connect to the completed PCB board.
Vetinari Clock – A clock that ticks randomly, but still keeps accurate time – [Link]
Here is a programmable timer project by Victor. It’s PIC18F4550 based and uses a DS1307 real time clock chip to keep time. A small 12 volt relay acts as the switch. [via]
This project, like others before, has started out of need: our 30+ year old mechanical timer for the central heater of the house has finally given it up. It would have been faster and cheaper to get a replacement from the local hardware store, but I decided to learn something new and I set out to create a digital version of it.
Programmable timer switch - [Link]
An Arduino-based clock with 180 RGB LEDs. The LEDs are driven via 12 TLC5925 1- channel constant-current addressable drivers – [via]
Its built on doublesided copper clad board using Toner transfer method. The routes aren’t smaller than 0.44mm and all vias are made for 0.8mm drilling (truly DIY). Just around 5 vias are under a component and 7 segment displays have singnals only from bottom side (for easy soldering)
- 180 RGB LEDs driven by TLC5925 constant current LED drivers
- each LED addressed separately (12x TLC5925 with 16 outputs each)
- each colour adressed individually
- 4x 7 segment LED display
- Atmega328P as MCU
- DS1307 real time clock
- Photoresistor (for adjusting brightness)
- And DHT11 for temperature and humidity
- Backup battery for clock
- 5V DC (eg USB)
Clock with 180 RGB LEDs on home-etched circuit board - [Link]
The goal of this project is to construct a simple 0-9999 seconds count down timer with an alarm and a display. The time is set through two tact switches and the count down seconds are displayed on a 4-digit seven segment LED display. The project uses PIC12F683 microcontroller for all I/O and timing operations and MAX7219 IC for driving the seven segment LED module. The time out condition is indicated by an audible alarm from a buzzer.
0-9999 seconds count down timer using PIC12F683 microcontroller - [Link]