refactor!: namespace nRF24L01.h defines to avoid name collisions

[Copilot]

Converts all #define macros in nRF24L01.h to typed constants under a namespace nRF24L01 to eliminate global namespace pollution and prevent name collisions (e.g., CD, TX_DS, RX_DR).

Changes

• nRF24L01.h:
  • Added include guards and #include <stdint.h>; replaced all #define macros with constexpr uint8_t constants inside namespace nRF24L01
  • renamed certain constants because prefixes are no longer needed inside a namespace:
    • NRF_CONFIG → CONFIG
    • NRF_STATUS → STATUS
    • RF24_NOP → NOP
• RF24.h:
  • Moved #include "nRF24L01.h" from inside a typedef enum block to top-level
  • updated enum values to use nRF24L01:: prefix
• RF24.cpp:
  • Added using namespace nRF24L01; to keep the implementation unchanged
  • updated all renamed references:
    • NRF_CONFIG → CONFIG
    • NRF_STATUS → STATUS
    • RF24_NOP → NOP

Migration

User code that includes nRF24L01.h and uses these constants directly must either add a using directive or qualify with the namespace prefix:

// Option A
using namespace nRF24L01;
write_register(CONFIG, ...);
spi_txbuff[0] = NOP;

// Option B
write_register(nRF24L01::CONFIG, ...);
spi_txbuff[0] = nRF24L01::NOP;

[github-actions]

Memory usage change @ 7c2159a

Board	Flash	%	RAM for global variables	%
arduino:avr:nano	0 - 0	0 - 0	0 - 0	0 - 0
arduino:samd:mkrzero	0 - 0	0 - 0	0 - 0	0 - 0

Click for full report per board

arduino:avr:nano

Sketch	Flash	%	RAM for global variables	%
examples/GettingStarted	0	0	0	0
examples/AcknowledgementPayloads	0	0	0	0
examples/ManualAcknowledgements	0	0	0	0
examples/StreamingData	0	0	0	0
examples/MulticeiverDemo	0	0	0	0
examples/InterruptConfigure	0	0	0	0
examples/scanner	0	0	0	0
examples/encodeRadioDetails	0	0	0	0

arduino:samd:mkrzero

Sketch	Flash	%	RAM for global variables	%
examples/GettingStarted	0	0	0	0
examples/AcknowledgementPayloads	0	0	0	0
examples/ManualAcknowledgements	0	0	0	0
examples/StreamingData	0	0	0	0
examples/MulticeiverDemo	0	0	0	0
examples/InterruptConfigure	0	0	0	0
examples/scanner	0	0	0	0
examples/encodeRadioDetails	0	0	0	0

[2bndy5]

🎉

No compile size consequence from switching to constexpr!

[2bndy5]

@TMRh20 What do you think? This should prevent further name collisions in the global namespace. I also reverted patches that were done to fix previously discovered collisions.

As for breaking user code, I don't think nRF24L01.h serves any real utility for users. It would seem as though most 3rd-party tutorials still #include <nRF24L01.h> because the old examples (from maniacbug days) did that needlessly.

[2bndy5]

Note

The new namespace is not confusingly added to the API docs

[TMRh20]

I think this is a great idea instead of renaming things every time there is a naming conflict.