Including SPI 3-wires class
Fork of X_NUCLEO_COMMON_SPI3W by
DevSPI/DevSPI.h
- Committer:
- Wolfgang Betz
- Date:
- 2015-10-19
- Revision:
- 12:fb6321e37154
- Child:
- 13:9a2c9b0bbe61
- Child:
- 14:7e8db11e12c7
File content as of revision 12:fb6321e37154:
/** ****************************************************************************** * @file DevSPI.h * @author AST / Software Platforms and Cloud * @version V0.0.1 * @date September 24th, 2015 * @brief Header file for a special SPI class DevSPI which provides some * helper function for on-board communication. ****************************************************************************** * @attention * * <h2><center>© COPYRIGHT(c) 2014 STMicroelectronics</center></h2> * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. Neither the name of STMicroelectronics nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************** */ /* Define to prevent from recursive inclusion --------------------------------*/ #ifndef __DEV_SPI_H #define __DEV_SPI_H /* Includes ------------------------------------------------------------------*/ #include "mbed.h" /* Classes -------------------------------------------------------------------*/ /** Helper class DevSPI providing functions for SPI communication common for a * series of SPI devices. */ class DevSPI : public SPI { public: /* * Create a DevSPI interface. * @param mosi pin name of the MOSI pin of the SPI device to be used for communication. * @param miso pin name of the MISO pin of the SPI device to be used for communication. * @param sclk pin name of the SCLK pin of the SPI device to be used for communication. */ DevSPI(PinName mosi, PinName miso, PinName sclk) : SPI(mosi, miso, sclk) { bits = 9; mode = 0; frequency_hz = 1E6; setup_done = false; } /* * Setup the spi. * Typically: * + 8 bit data; * + high steady state clock; * + second edge capture; * + 1MHz clock rate. * * @param bits Number of bits per SPI frame (4 - 16) * @param mode Clock polarity and phase mode (0 - 3) * @param frequency_hz SCLK frequency in hz (default = 1MHz) * * @code * mode | POL PHA * -----+-------- * 0 | 0 0 * 1 | 0 1 * 2 | 1 0 * 3 | 1 1 * @endcode */ void setup(int bits, int mode = 0, int frequency_hz = 1E6) { format(bits, mode); frequency(frequency_hz); setup_done = true; } /** * @brief Writes a buffer to the SPI peripheral device. * @param[in] pBuffer pointer to the buffer of data to send. * @param[in] ssel GPIO of the SSEL pin of the SPI device to be used for communication. * @param[in] NumBytesToWrite number of bytes to write. * @retval 0 if ok. * @note When using the SPI in Interrupt-mode, remember to disable interrupts * before calling this function and to enable them again after. */ int spi_write(uint8_t* pBuffer, DigitalOut ssel, uint16_t NumBytesToWrite) { /* Setup. */ if (!setup_done) { ssel = 1; setup(8, 3, 1E6); setup_done = true; } /* Select the chip. */ ssel = 0; /* Write data. */ for (int i = 0; i < NumBytesToWrite; i++) write(pBuffer[i]); /* Unselect the chip. */ ssel = 1; return 0; } /** * @brief Reads a buffer from the SPI peripheral device. * @param[out] pBuffer pointer to the buffer to read data into. * @param[in] ssel GPIO of the SSEL pin of the SPI device to be used for communication. * @param[in] NumBytesToRead number of bytes to read. * @retval 0 if ok. * @note When using the SPI in Interrupt-mode, remember to disable interrupts * before calling this function and to enable them again after. */ int spi_read(uint8_t* pBuffer, DigitalOut ssel, uint16_t NumBytesToRead) { /* Setup. */ if (!setup_done) { ssel = 1; setup(8, 3, 1E6); setup_done = true; } /* Select the chip. */ ssel = 0; /* Read data. */ for (int i = 0; i < NumBytesToRead; i++) pBuffer[i] = write(0x00); /* Unselect the chip. */ ssel = 1; return 0; } /** * @brief Reads and write a buffer from/to the SPI peripheral device at the same time. * @param[out] pBufferToRead pointer to the buffer to read data into. * @param[in] pBufferToWrite pointer to the buffer of data to send. * @param[in] ssel GPIO of the SSEL pin of the SPI device to be used for communication. * @param[in] NumBytes number of bytes to read and write. * @retval 0 if ok. * @note When using the SPI in Interrupt-mode, remember to disable interrupts * before calling this function and to enable them again after. */ int spi_read_write(uint8_t* pBufferToRead, uint8_t* pBufferToWrite, DigitalOut ssel, uint16_t NumBytes) { /* Setup. */ if (!setup_done) { ssel = 1; setup(8, 3, 1E6); setup_done = true; } /* Select the chip. */ ssel = 0; /* Read and write data at the same time. */ for (int i = 0; i < NumBytes; i++) pBufferToRead[i] = write(pBufferToWrite[i]); /* Unselect the chip. */ ssel = 1; return 0; } protected: bool setup_done; int bits; int mode; int frequency_hz; }; #endif /* __DEV_SPI_H */