need help on project

Thread Starter

mtmaidoki

Joined Jul 5, 2011
3
I am a novice in programming and working on the design of a digital clock with calendar and temperature display. Though, I have soldered the project to working conditions, I am encountering some difficulties which I suspect to be from the source code.
The problem is such that if I power the device, it seems to hang without showing the time, calendar and temperature. But after pressing the RESET button on several times it showed the data without running the clock and the current temperature is displayed only after I press the INCR button.
Thus attached are the circuit diagram and source code, and I hope someone would put me through. Thanks in advance
 

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SgtWookie

Joined Jul 17, 2007
22,230
It appears that you exported the schematic as a .jpg before you embedded it into a Microsoft Word document.

This makes the schematic blurry and hard to read. Putting it in a Word document limits the number of people who can look at the schematic.

Also, you apparently left the display of PINS turned on before you exported the image. Please turn the PINS layer display off; it makes the schematic harder to read.

Please export your schematic as a .png image (which is not lossy like .jpg is), in 100dpi to 120dpi resolution, and attach the .png image directly without embedding it into a Word document.

It looks like you did not use bypass capacitors across the power and ground pins of your ICs, which will cause you big problems. As a minimum requirement, each IC needs at least one 0.1uF capacitor across its' power and ground pins.
 
Last edited:

n1ist

Joined Mar 8, 2009
189
You need to add decouipling caps to your circuit; one 100nF (0.1uF) cap per power pin of each chip, located close to the pin.

/mike
 
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