> waking the CPU from sleep to resume execution seems a bit complex

Complex doesn't necessarily mean difficult. Execute a SLEEP and wake
with the interrupt of choice. In your case, a key

> And is it just me or does the PIC32 consume MORE power in sleep mode
> than using the LPRC (31 KHz) according to the datasheet?

According to the d/s

All of the devices in the PIC32MX family incorporate a range of features
that can significantly reduce power consumption during operation. Key features
include:

. On-the-Fly Clock Switching: The device clock can be changed under
software control to any of the four clock sources during operation.
. Instruction-Based Power-Saving Modes: The microcontroller can suspend
all operations, or selectively shut down its core while leaving its peripherals
active, with a single instruction in software.

SLEEP Mode: the CPU, the system clock source, and any peripherals that
operate from the system clock source, are halted. Some peripherals can
operate in SLEEP using specific clock sources. This is the lowest power
mode for the device.

And, if I've understood the d/s at a glance

@ 3.6V, 25C, 31kHz

Sleep DC40e 70uA

Idle DC36a 106uA

Run DC26a 180uA

Full power 80MHz, DC33b 32mA

You need to work out "Instructions Needed vs Speed vs Current"

IOW, for the sake of simplicity, say you have a function which takes
1000 instruction cycles

Full speed is 80MHz, or 2580 x 31kHz

Full speed current is 32000uA, or 178 x 180uA

Therefore, performing a calculation at full speed theoretically uses
178/2580th or 1/15th the wattage at 31kHz, because the uC is on
for a much shorter time and gets through the task 15 x faster

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist