| .. _module-pw_spi_rp2040: |
| |
| ============== |
| pw_spi_rp2040 |
| ============== |
| |
| ``pw_spi_rp2040`` implements the ``pw_spi`` interface using the |
| `Raspberry Pi Pico SDK <https://github.com/raspberrypi/pico-sdk/>`_. |
| |
| The implementation is based on the SPI driver in pico_sdk. SPI transfers use |
| the blocking driver API which uses busy waiting under the hood. |
| |
| .. note:: |
| There is currently no support for RP2040 hardware CSn |
| pins. ~pw::spi::DigitalOutChipSelector~ is used instead. |
| |
| Usage |
| ===== |
| .. code-block:: cpp |
| |
| #include "hardware/spi.h" |
| #include "pw_digital_io/polarity.h" |
| #include "pw_digital_io_rp2040/digital_io.h" |
| #include "pw_spi/chip_selector_digital_out.h" |
| #include "pw_spi/device.h" |
| #include "pw_sync/borrow.h" |
| #include "pw_sync/mutex.h" |
| |
| constexpr pw::spi::Config kSpiConfig8Bit{ |
| .polarity = pw::spi::ClockPolarity::kActiveHigh, |
| .phase = pw::spi::ClockPhase::kFallingEdge, |
| .bits_per_word = pw::spi::BitsPerWord(8), |
| .bit_order = pw::spi::BitOrder::kMsbFirst, |
| }; |
| |
| pw::digital_io::Rp2040DigitalInOut display_cs_pin({ |
| .pin = 12, |
| .polarity = pw::digital_io::Polarity::kActiveLow, |
| }); |
| DigitalOutChipSelector spi_chip_selector(display_cs_pin); |
| |
| Rp2040Initiator spi_initiator(spi0); |
| VirtualMutex spi_initiator_mutex; |
| Borrowable<Initiator> borrowable_spi_initiator(spi_initiator, |
| spi_initiator_mutex); |
| pw::spi::Device spi_8_bit(borrowable_spi_initiator, |
| kSpiConfig8Bit, |
| spi_chip_selector); |
| |