Go Down

Topic: Alarm clock from Atmega328 and 7-segment display (Read 6 times) previous topic - next topic

Nick Gammon

#5
Jun 11, 2011, 12:22 am Last Edit: Jun 11, 2011, 12:58 am by Nick Gammon Reason: 1
Thanks everyone!

Just to cost it all:


  • 7-segment display: $4

  • Atmega328: $6

  • DS1307 breakout board from Adafruit: $18 (however similar one for $7.90 from Futurlec)

  • Switches: $2 each approx

  • LM7805: $5

  • Buzzer: $1.50

  • 16 MHz resonator: $0.80



Plus a few other small parts, the board, wires, etc.

But the fun thing is, you probably have the parts lying around anyway. :)

kalum

Excellent point to point wiring technique. Very nice and clean design.

CrossRoads

Wow, you guys get raped for material costs down under!
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Jack Christensen

Nice job, Nick!  I'm a clock fan myself.  Still in the breadboard phase here but thinking towards something more permanent.  I'm storing time zone offsets and DST adjustment rules in EEPROM, setting the RTC to UTC, and doing UTC-to-local conversion before sending the time to the display.  Might save a couple bucks on the switch  ;)
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

CrossRoads

I made different clocks back in college - transformer to get voltage down to a rectifiable voltage to make DC, dividing down the mains to make 1Hz.  One design had 60 LEDs in an outer circle for minutes, 12 in an inner circle for hours. Learned about switch bounce on that one too.
I still have the board for it, covered in dust in a box, chips pulled out for a later project.
The mix of hardware/software that uCs bring to the table make things a lot easier to bring to completion without a big pile of chips.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Go Up