Add board definition for Adafruit Feather RP2040 Adalogger

[b4shful]

Fixes #2522

Based off of the existing Adafruit Feather RP2040 header (adafruit_feather_rp2040.h)

The only changes made from the regular Feather RP2040 board header are:

• Change NeoPixel/WS2812 pin PICO_DEFAULT_WS2812_PIN from 16 to 17

• Add defs for SD card pins (see SD section in header).

Note on SD card pin defs:

I followed the conventions used for other boards with SD card pins defined, although none of the other boards I looked at had the SD "Card Detect" pin mapped so I named its pin PICO_SD_CARD_DETECT_PIN.

I think this should be all that is needed to provide minimal support for Pico SDK on this board variant, but please do let me know if I'm missing something.

[b4shful]

I realised that PICO_DEFAULT_SPI is currently set to 0. However this is the SPI peripheral Adafruit specifies is used for the SD card.

SPI1 is unused by default and corresponds to the MOSI/MISO/SCK silkscreen labels on the Feather RP2040 Adalogger, so perhaps I should have defined PICO_DEFAULT_SPI as 1 instead?

[b4shful]

Sorry, got a bit confused there.

The default SPI instance and pins from the original Feather RP2040 header file are what the Adalogger board uses for the SD card. So I will need to edit the PICO_DEFAULT_SPI defs to instead use SPI1 and the correct pins for this as silkscreened on the board.

[b4shful]

Sorry, got a bit confused there.

The default SPI instance and pins from the original Feather RP2040 header file are what the Adalogger board uses for the SD card. So I will need to edit the PICO_DEFAULT_SPI defs to instead use SPI1 and the correct pins for this as silkscreened on the board.

Committed the required edits for this.

As a note, the macros PICO_DEFAULT_SPI_TX_PIN and PICO_DEFAULT_SPI_RX_PIN seem confusingly named as TX and RX could be the complete opposite depending on the role the SPI peripheral is configured in.

I set TX to the pin silkscreened on the board as MOSI, and RX for the silkscreened MISO, should be correct.

[lurch]

Committed the required edits for this.

Based on that, I'll mark this as ready for review.

As a note, the macros PICO_DEFAULT_SPI_TX_PIN and PICO_DEFAULT_SPI_RX_PIN seem confusingly named as TX and RX could be the complete opposite depending on the role the SPI peripheral is configured in.

Yup, see section 4.4.3.15 of https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.pdf