Important changes to repositories hosted on mbed.com
Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.
To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.
It is also possible to export all your personal repositories from the account settings page.
SPIHalfDuplex Class Reference
A SPI half-duplex master, used for communicating with SPI slave devices over a shared data line. More...
#include <SPIHalfDuplex.h>
Inherits mbed::SPI.
Public Member Functions | |
| SPIHalfDuplex (PinName mosi, PinName miso, PinName sclk) | |
| Create a SPI half-duplex master connected to the specified pins. | |
| virtual int | write (int value) |
| Write to the SPI Slave and return the response. | |
| void | slave_format (int sbits) |
| Set the number of databits expected from the slave, from 4-16. | |
| void | format (int bits, int mode=0) |
| Configure the data transmission format. | |
| void | frequency (int hz=1000000) |
| Set the spi bus clock frequency. | |
| virtual void | lock (void) |
| Acquire exclusive access to this SPI bus. | |
| virtual void | unlock (void) |
| Release exclusive access to this SPI bus. | |
| template<typename Type > | |
| int | transfer (const Type *tx_buffer, int tx_length, Type *rx_buffer, int rx_length, const event_callback_t &callback, int event=SPI_EVENT_COMPLETE) |
| Start non-blocking SPI transfer using 8bit buffers. | |
| void | abort_transfer () |
| Abort the on-going SPI transfer, and continue with transfer's in the queue if any. | |
| void | clear_transfer_buffer () |
| Clear the transaction buffer. | |
| void | abort_all_transfers () |
| Clear the transaction buffer and abort on-going transfer. | |
| int | set_dma_usage (DMAUsage usage) |
| Configure DMA usage suggestion for non-blocking transfers. | |
Protected Member Functions | |
| int | transfer (const void *tx_buffer, int tx_length, void *rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t &callback, int event) |
| Common transfer method. | |
| void | irq_handler_asynch (void) |
| SPI IRQ handler. | |
| int | queue_transfer (const void *tx_buffer, int tx_length, void *rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t &callback, int event) |
| void | start_transfer (const void *tx_buffer, int tx_length, void *rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t &callback, int event) |
| Configures a callback, spi peripheral and initiate a new transfer. | |
| void | start_transaction (transaction_t *data) |
| Start a new transaction. | |
| void | dequeue_transaction () |
| Dequeue a transaction. | |
Detailed Description
A SPI half-duplex master, used for communicating with SPI slave devices over a shared data line.
The default format is set to 8-bits for both master and slave, and a clock frequency of 1MHz
Most SPI devies will also require Chip Select and Reset signals. These can be controlled using <DigitalOut> pins.
Although this is for a shared data line, both MISO and MOSI are defined, and should be tied together externally to the mbed. This class handles the tri-stating of the MOSI pin.
Example:
// Send a byte to a SPI half-duplex slave, and record the response #include "mbed.h" SPIHalfDuplex device(p5, p6, p7) // mosi, miso, sclk int main() { int respone = device.write(0xAA); }
Definition at line 42 of file SPIHalfDuplex.h.
Constructor & Destructor Documentation
| SPIHalfDuplex | ( | PinName | mosi, |
| PinName | miso, | ||
| PinName | sclk | ||
| ) |
Create a SPI half-duplex master connected to the specified pins.
Pin Options: (5, 6, 7) or (11, 12, 13)
mosi or miso can be specfied as NC if not used
- Parameters:
-
mosi SPI Master Out, Slave In pin miso SPI Master In, Slave Out pin sclk SPI Clock pin name (optional) A string to identify the object
Definition at line 16 of file SPIHalfDuplex.cpp.
Member Function Documentation
| void slave_format | ( | int | sbits ) |
Set the number of databits expected from the slave, from 4-16.
- Parameters:
-
sbits Number of expected bits in the slave response
Definition at line 22 of file SPIHalfDuplex.cpp.
Generated on Tue Jul 12 2022 17:35:15 by
1.7.2