Blinky doesn't work when using develop/release profile with external power

[MarceloSalazar]

Description

• Type: Bug
• Related issue: UBLOX EVK NINA B1: mbed 5.5 regression on Serial class (nrf5) #4686
• Priority: Major

---

Bug

Target
u-blox-EVK-NINA-B1

Toolchain:
GCC_ARM

gcc 6.3.1

mbed-cli version:
1.2.0

mbed-os sha:
mbed OS 5.5.6 (98ba8ac)

DAPLink version:
243

Expected behavior
Blinky should just work fine with all profiles (debug, release, develop), regardless of whether you use the USB port or external power supply.

Actual behavior
Blinky doesn't work when using the develop and release profiles with external power supply of the NINA B1 platform. It does work well with the debug profile.
It seems the system goes to sleep and never wakes up.

This has been found when working with @NeilMacMullen and @pan-

[ghost]

@MarceloSalazar : can you try the current master branch of mbed-os?

[MarceloSalazar]

I've tried Blinky with mbed-os-5.6.0-rc1 and can see this working on NINA when using release/develop profiles.

@NeilMacMullen could you give it a try on your custom platform and confirm?

[pan-]

#5086 will also help new targets to avoid this issue in the future.

[MarceloSalazar]

Confirmed it's solved.