My kit reset time to 00:00 01-01-2000 each power cycle

zerog2k / stc_diyclock

STC DIY Clock redux (STC15F204EA, STC15W404AS, STC15W408AS)

MIT License

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My kit reset time to 00:00 01-01-2000 each power cycle #59

Closed IgorTrud closed 2 years ago

IgorTrud commented 2 years ago

I checked battery voltage on DS1302 directy - fine 2.98V I checked XTAL - running nicely at 32 kHz even in no-power state. Any ideas what could be wrong ? Is there any FUSE bits, what need to be set during MCU flashing to avoid this ?

Chip is 15W404AS. I have the same issue on "original" chinise firmware too...

zerog2k commented 2 years ago

I have the same issue on "original" chinise firmware too

some hardware issue - mcu maybe cannot talk to ds1302 usually missing pullup/pulldown, or problem with clock/data lines. maybe problem during assembly - recheck schematics, soldering, etc.

IgorTrud commented 2 years ago

Yes, it was HW issue. DS1302 should have some capacitance on Vcc and Vbat pin, otherwise it resets during switch. No software issues, closing.