Hi John,
Great write up but out of date, nice if he would revise it.
Check you compile output warnings, I think you will see …
Warning: ‘wait_ms’ is deprecated: ‘wait_ms’ is deprecated in favor of explicit sleep functions. To sleep, ‘wait_ms’ should be replaced by ‘ThisThread::sleep_for’ (C++) or ‘thread_sleep_for’ (C). If you wish to wait (without sleeping), call ‘wait_us’. ‘wait_us’ is safe to call from ISR context. [since mbed-os-5.14] [-Wdeprecated-declarations]
There’s some more information that may help you here regarding GPIO settings to reduce deepsleep mode current consumption, this is important on these ST’s…
Paul