Add ESP-32 Wi-Fi and BLE driver

[chrissnow]

Summary of changes

Add Renesas ESP-32 driver which adds Wi-Fi and BLE support to any target with a serial port at very low cost

Impact of changes

Migration actions required

Documentation

TBC?

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Pull request type

[] Patch update (Bug fix / Target update / Docs update / Test update / Refactor)
[] Feature update (New feature / Functionality change / New API)
[] Major update (Breaking change E.g. Return code change / API behaviour change)

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Test results

[] No Tests required for this change (E.g docs only update)
[] Covered by existing mbed-os tests (Greentea or Unittest)
[] Tests / results supplied as part of this PR

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[multiplemonomials]

Is there an Mbed board that has an ESP32 on it? One of the Renesas ones it seems like?

[chrissnow]

Both GR-LCYHEE and GR-PEACH.
It's useful to anybody that wants to add Wi-Fi and ble to any target at very low cost also.

[multiplemonomials]

Might have to order one of those boards to run the wifi tests on it, unless you have one

[multiplemonomials]

@chrissnow would you be able to take a look at these CI failures? Also could you confirm whether you have a board with this chip on it to test on?

[chrissnow]

@multiplemonomials it build OK so I wonder whey it's failing, can mbed.h not be included here?
I notice the ESP8266 driver includes various internal headers instead which may be the answer.

I don't have a Renesas board, but do have various ESP32 dev boards, we have one attached to a STM32 for testing.
You just need to flash the ESP-AT firmware and connect the UART, ideally with flow control!

I will tidy up and report back but it might be next week now.

[multiplemonomials]

Yeah I think that things inside mbed os should include only the specific headers they need (e.g. NetworkInterface.h) rather than the top level mbed.h

[chrissnow]

Not yet fully tested but issues should now be resolved.