HC-04 Bluetooth module and BlueCore4 Deep Sleep

The good news is that BlueCore indeed has Deep Sleep mode, it's not marketing hype. It can be verified by configuring PSKEY_CLOCK_REQUEST_ENABLE to drive PIO when chip uses/doesn't use external clock. The key here is not to keep PSTool run (which well, you need to tweak sleep settings).

The bad news is that an HC-04 module in Deep Sleep still consumes 2.5mA, which is far too high for anything called Deep Sleep. So, something on the module besides BlueCore still consumes too much power. However, when BlueCore is held in reset state, entire module consumes 0.

Without Deep Sleep, simple LED flash task consumes 3.5mA, so there's not that much gain from the Deep Sleep...