Posted on October 28, 2017 at 00:57I am using M41T81S chip for a RTC.
I am having a issue keeping a time on power down.
I borrowed the circuit from following location.
http://www.niell.org/nixie_3/NixieClock5-1.bmp
Instead of C2 in the picture, I am using 1F super Cap.
Even on power down condition (removing +5V), M41T81S should continue counting time as long as proper voltage applied to Vbat.
On my setupt, I verified that Vbat remains 3.3V at all time, but timer resets to 00:00:00 as soon as main supply is removed.
Would you please help me solving this issue?
Also, is there sample code I can follow to communicate with this chip?
Attached 'Code.PNG' is a startup sequence I am using to start up this RTC chip.
Thank you,
Toru
