I verified both manufacturer datasheets and their top-view pinouts. I’ll compare the industrial DS3231SN# and DS1307ZN+ variants. They are not pin-compatible, and the DS1307 needs an external crystal and a different main-supply range. I’ll add only the new guide and leave the existing file untouched.
For DS1307 vs DS3231, the key difference is an external crystal versus an integrated temperature-compensated clock. Choose DS3231SN# for temperature-compensated timekeeping and alarms, or DS1307 for a compatible main supply and battery-backed user RAM when external-crystal accuracy is acceptable.
Variant scope: DS3231SN# is the industrial 16-lead SO device; the DS1307 reference here is DS1307ZN+, the industrial 8-lead SO device, not the commercial DS1307Z+ or the PDIP version. Both selected variants cover ambient temperature TA = −40°C to +85°C,...
The existing Application and Usage Guide and all other project content were left unchanged.
Values left out:
Numeric DS1307 clock accuracy: the manufacturer specifies dependence on the external crystal and circuit, not a fixed tolerance.
Current-consumption rankings and battery-life estimates: no matched-condition comparison or complete battery model was verified.
Pinout risk: They are not pin-compatible. Replacement requires a different footprint, rewiring, supply/crystal changes, and firmware changes. Manufacturer pinouts were checked; library footprints and hardware were not audited.