Fyuh.. My friends came again to me asking for help, then i guest “it must be their PI related to electronic”. But, nevermind i like to do that :D. As could as possible, the task should be solderless. Damn.. im so f*ck*ng lazy soldering IC’s pin. It could be nice to buy development board for your project dude. So i recommend my friends to buy the devboard. Electronic hobbyist tend to build the board by himself, but i think it is wasting time. There is one way as electronic hobbyist to press budget and time, IMHO, yeah.. find your friend who needs her/his project done ASAP, he/she will give tools, kits & components needed by you and probably a tip. In my case, i don’t need to find them, they come to me already. Last project was digital temperature, using AVR’s ADC, which controls two fans and monitored via LCD. Now, same thing in using LCD, digital clock with alarm and stopwatch. For you, who is familiar with electronic might blame my friend as a foolish. Ya.. ya.. there are many many application note, articles, tutorials strip this project. So who is wrong when someone has money to help hobbyist kill their boring day.

So what you gonna build today, gedex? Just like i said “digital clock with alarm & stopwatch feature”. In addition, other friend also request me to change his already apps, just minor modification. For this digital clock, i use AT89S51/52 as controller, DS1302 for RTC, 93C66 for EEPROM. For you who is interested, here is the code written in assembler (1600 lines). Use new firmware for ‘no reset’ on RTC below.

Happy debugging :D
To get my digital clock schematic just drop me a message.

Update new firmware here. This time, the program doesn’t reset the clock each time you unplug the power. But for saving alarm time, i still got problem when writing to EEPROM. Anyone can help??

Note : Hari’s program here, based on this app, which i wrote the program in assembler plus added swicth connected to INT0 for switching startup (20,30,40, and 60).