M.2 modules

this section covers m 2 expansion modules testsing flipper one has m 2 key b (s3), has usb and pcie interfaces in m 2 port m 2 port tech specification auto config detection in the m 2 spec, config pins are strap / detection pins used by the host (and sometimes the module) to determine what interface the module expects (usb vs pcie) what role or mode should it boot in sometimes the module class (wwan, ssd, etc ) they are sampled at power up or reset depending on the m 2 key , different pins are used key b / b+m (wwan modems) common config related pins config 1 config 2 sometimes reused gpio / led / uart pins key m (ssds) mostly pcie / sata focused, config pins usually select pcie vs sata lane width (x2 / x4) for modems , this is much more vendor specific than for ssds ❓❓ how to test detect pins?❓❓ m 2 modems m 2 modems can vary significantly different form factors flipper one supports only 30×52 and 30×42 different connection interfaces usb and pcie different auxiliary pins uart, led, and other signals may be routed to unused pins of the m 2 connector sim card test install sim card in flipper one port verify that it visible on modem usb only modem verify that modem only has usb interface connect that it works properly pcie only modem verify that modem only has pcie interface (its exist?) connect that it works properly pcie+usb modem verify that modem only has both pcie+usb interfaces connect that it works properly modem activity led pins most m 2 modems have activity led on some pins ssd disk todo