Pre 2023:

This is the config we’re going with:

Darrian: find datasheet for the chip and find parts on digikey that match the specifications given in the layout, MAKE SURE ITS IN STOCK

Using the AB1815-T3 WDT/RTC

Digikey part: https://www.digikey.ca/en/products/detail/abracon-llc/AB1815-T3/3661500  (in stock)

Note: Recommended tuning fork crystal is ABS07-120-32.768kHz-T. -> XO - XI

https://www.digikey.ca/en/products/detail/abracon-llc/ABS07-120-32-768KHZ-T/3724043?s=N4IgTCBcDaIIICEDKAGA7AWgIxhRgzBALoC%2BQA (in stock)

Need impedance of backup battery, since backup + external = 1.5kohm

https://www.digikey.ca/en/products/detail/panasonic-electronic-components/ERA-1ARW152C/6568054 (this is one of two in stock lmao) for 1.5kohm, probably not right?

**Questions to ask:**What does the mcu do

Which configuration are we going with

What is the resistance of the backup battery

‘Reset driven with backup battery’ does that just mean combine the two circuits w/ the extra input for mcu reset

Pin 17 (VSS) connected to ground

Current understanding is

Deciding between 3 (reset driven) and 4 (battery backup)

For the time: can either program rtc before launch and use option 4 (battery backup) to save the time while the satellite is powered off during launch

Or can just use 3 (reset) and somehow sync time w/ gps after launch if thats possible