LM8560 Digital Clock IC Library

Other Hardware Hardware Development
1

I'm writing a library for the LM8560 Digital Clock IC. It not only is an alarm enabled clock, it has a built in LED display controller. It's also found in most cheap alarm clocks. I might later take part in developing a shield. The LM8560 is usually implemented in circuits that do not have a crystal or any other form of oscillator, instead it uses the AC waveform. This may pose a problem, since it appears the whole thing runs on AC. I might try it with DC and use the arduino's PWM to replicate a 60Hz waveform and see if it still works.

Though this probably wouldn't be acceptable for a library. It would change the timers of the AVR, therefore causing things like delay(), millis(), and others not to work correctly. I'm thinking either use a crystal or a 555 timer, though that might have stability issues.

Some practical uses for this are:

  • To provide a steady 1 second interrupt. (Could be useful for timing and such)
  • To provide a RTC. (This would basically just probe the display pins and determine what the time is based on their state.)
  • To provide a timer system. (Basically just set the alarm time to something and use the alarm output as an interrupt.)

A backup supply can also be used with this IC. I'm thinking for a way to set the clock is to provide a basic sketch which will take input from the serial port and then use that to set the time.

Any ideas or questions?

2

I might try it with DC and use the arduino's PWM to replicate a 60Hz waveform and see if it still works.

That won't produce alternating current. You'll simply have a square wave that goes from 0 to 5V with varying widths, depending on the input value.

It would change the timers of the AVR, therefore causing things like delay(), millis(), and others not to work correctly.

Why?