Serial connection with microcontroller in alarm clock?

Thread Starter

captainam3rica

Joined Jun 17, 2011
3
I'm pretty new to the world of microprocessors and such, I recently purchased and started playing with an Arduino board. I have a cheapo alarm clock that has four pins on the PCB labeled dr, clk, data, and gnd. From my initial research I think they may be for an SPI connection. Basically I'm trying to figure out if I can create a serial connection between the alarm clock microprocessor and my arduino to perhaps read data from the alarm clock such as time, date, temperature, etc. Any ideas or input? I don't really know where to start. Thanks



 

absf

Joined Dec 29, 2010
1,968
I think the 4 signals is used to program the clock chip after the components are assembled. Dont you think the 4 wires CLR, CLK, DATA, GND are silmilar to the 4 signals on the PIC namely MCLR, PDC, PGD and GND?

There may be a few models of this clock each with slightly different functions or different languages for different markets so they need different programs.

Allen
 

ErnieM

Joined Apr 24, 2011
8,377
Since the unit uses a "glob top" to cover the raw IC chip doing all the hard work it is pretty darn near impossible to find out what exactly is inside there. I would say impossible except for the small change the manufacturer is willing to provide that information to you.

There are some pretty darn good chips with full documentation that keep time. Here's two of them:

http://www.digikey.com/product-detail/en/PCF2129AT%2F1,512/568-4960-5-ND/2192973

http://www.digikey.com/product-detail/en/DS3231S#/DS3231S#-ND/1197574

You can drop one in your system and keep it running for 5+ years with a coil cell battery.
 
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