Reduce flash usage up to 214k in one click

[romansavrulin]

This PR gets rid of stringstream and exception usage in @nkolban BLE library. While stringstream itself is a good and safe thing on mature desktop platforms, using it in embedded world mostly for debugging purposes has its impact. In this case we can save about 214k.

Here's a metrics of my test image build.

• Stringsream=y
• Exceptions in idf toolchain=y
• Exceptions in library=y

$ ls -al build/
-rw-r--r--   1 user  staff    628288 25 июн 16:45 firmware_.bin

---

• Stringsream=n
• Exceptions in library=n
• Exceptions in idf toolchain=y

Note: by default exceptions seems to be enabled in Arduino build configuration. So, actual flash size benefit from this PR on most platforms can be about 137k.

---

$ ls -al build/
-rw-r--r--   1 user  staff    491184 25 июн 16:49 firmware_.bin

---

• Stringsream=n
• Exceptions in library=n
• Exceptions in idf toolchain=n

$ ls -al build/
-rw-r--r--   1 user  staff   413616 25 июн 16:38 firmware_.bin

[me-no-dev]

Big thumbs up! :)

[romansavrulin]

@AlexFundorin Don't know actually. I use idf with my own libraries with submodules. But this fix is in the master now. Maybe it will be available after next release of plaformio metadata packages.

If you manage to get it work, just let us know

[AlexFundorin]

If you manage to get it work, just let us know

You were fast, Roman.

In platformio.io I've changed
platform = espressif32
to
platform = https://github.com/platformio/platform-espressif32.git#feature/stage

Before change:

DATA:    [==        ]  21.5% (used 70400 bytes from 327680 bytes)
PROGRAM: [========= ]  87.6% (used 1721570 bytes from 1966080 bytes)

After (same sketch):

DATA:    [==        ]  20.4% (used 66972 bytes from 327680 bytes)
PROGRAM: [========  ]  80.2% (used 1577378 bytes from 1966080 bytes)

[romansavrulin]

@AlexFundorin if you manage to change .config in idf , disable exceptions there and supply new idf binaries to platformio, you will get extra 77 kB