What do the different reset types mean, and why do we get them?

The reset types, as well as some documentation as to likely reason for occurrence, are listed in stack/include/ember-types.h. Also, this information is available under the "enumerator" section of our API document. As of 2.5.3, here is the list of reset types and their most likely cause(s).

RESET_UNKNOWN
The cause of this reset is unknown.

RESET_EXTERNAL
The RESET pin was pulled to logic low (0.0 V).

RESET_POWERON
The supply voltage was below the power-on threshold.

RESET_WATCHDOG
The Watchdog Timer period expired. This implies that the Watchdog is enabled.

RESET_BROWNOUT
The supply voltage went below the brown-out threshold. This implies that the brown out detector was enabled.

RESET_JTAG
The JTAG Reset Register was set to a logic 1.

RESET_ASSERT
A self-check in the code failed unexpectedly. Depending on your debug level, this should give some additional information about the specific self-check.

RESET_RSTACK
The return address stack (RSTACK) went out of bounds, either because the application went too deep into the function call list, or because of a stray pointer.

RESET_CSTACK
The data stack (CSTACK) went out of bounds, either because the application went too deep into the function call list, or because of a stray pointer.

RESET_BOOTLOADER
The bootloader deliberately caused a reset. This normally occurs when

RESET_PC_ROLLOVER
The program counter rolled over. This is currently XAP2B (EM250) specific.

RESET_SOFTWARE
The node software deliberately caused a reset. This is currently XAP2B (EM250) specific.

RESET_PROTFAULT
An attempt was made to access memory or registers by the application that are not available to the application. In 2.5.3, this is commonly a result of an uninitialized pointer, as RAM address 0x0000 is protected.

RESET_FLASH_VERIFY_FAIL
Flash verification failed. This is currently XAP2B (EM250) specific.

RESET_FLASH_WRITE_INHIBIT
An attempt was made to write to a flash address that had already been written. This is currently XAP2B (EM250) specific.