Lee Kai Xuan / mbed-os

mbed-os

Fork of mbed-os by erkin yucel

features/unsupported/tests/libs/SPIHalfDuplex/SPIHalfDuplex.h@0:f269e3021894, 2016-10-23 (annotated)

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

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elessair 0:f269e3021894 1 /* mbed Microcontroller Library - SPIHalfDuplex
elessair 0:f269e3021894 2 * Copyright (c) 2010-2011 ARM Limited. All rights reserved.
elessair 0:f269e3021894 3 */
elessair 0:f269e3021894 4 #ifndef MBED_SPIHALFDUPLEX_H
elessair 0:f269e3021894 5 #define MBED_SPIHALFDUPLEX_H
elessair 0:f269e3021894 6
elessair 0:f269e3021894 7 #include "platform.h"
elessair 0:f269e3021894 8
elessair 0:f269e3021894 9 #if DEVICE_SPI
elessair 0:f269e3021894 10
elessair 0:f269e3021894 11 #include "SPI.h"
elessair 0:f269e3021894 12
elessair 0:f269e3021894 13 namespace mbed {
elessair 0:f269e3021894 14
elessair 0:f269e3021894 15 /** A SPI half-duplex master, used for communicating with SPI slave devices
elessair 0:f269e3021894 16 * over a shared data line.
elessair 0:f269e3021894 17 *
elessair 0:f269e3021894 18 * The default format is set to 8-bits for both master and slave, and a
elessair 0:f269e3021894 19 * clock frequency of 1MHz
elessair 0:f269e3021894 20 *
elessair 0:f269e3021894 21 * Most SPI devies will also require Chip Select and Reset signals. These
elessair 0:f269e3021894 22 * can be controlled using <DigitalOut> pins.
elessair 0:f269e3021894 23 *
elessair 0:f269e3021894 24 * Although this is for a shared data line, both MISO and MOSI are defined,
elessair 0:f269e3021894 25 * and should be tied together externally to the mbed. This class handles
elessair 0:f269e3021894 26 * the tri-stating of the MOSI pin.
elessair 0:f269e3021894 27 *
elessair 0:f269e3021894 28 * Example:
elessair 0:f269e3021894 29 * @code
elessair 0:f269e3021894 30 * // Send a byte to a SPI half-duplex slave, and record the response
elessair 0:f269e3021894 31 *
elessair 0:f269e3021894 32 * #include "mbed.h"
elessair 0:f269e3021894 33 *
elessair 0:f269e3021894 34 * SPIHalfDuplex device(p5, p6, p7) // mosi, miso, sclk
elessair 0:f269e3021894 35 *
elessair 0:f269e3021894 36 * int main() {
elessair 0:f269e3021894 37 * int respone = device.write(0xAA);
elessair 0:f269e3021894 38 * }
elessair 0:f269e3021894 39 * @endcode
elessair 0:f269e3021894 40 */
elessair 0:f269e3021894 41
elessair 0:f269e3021894 42 class SPIHalfDuplex : public SPI {
elessair 0:f269e3021894 43
elessair 0:f269e3021894 44 public:
elessair 0:f269e3021894 45
elessair 0:f269e3021894 46 /** Create a SPI half-duplex master connected to the specified pins
elessair 0:f269e3021894 47 *
elessair 0:f269e3021894 48 * Pin Options:
elessair 0:f269e3021894 49 * (5, 6, 7) or (11, 12, 13)
elessair 0:f269e3021894 50 *
elessair 0:f269e3021894 51 * mosi or miso can be specfied as NC if not used
elessair 0:f269e3021894 52 *
elessair 0:f269e3021894 53 * @param mosi SPI Master Out, Slave In pin
elessair 0:f269e3021894 54 * @param miso SPI Master In, Slave Out pin
elessair 0:f269e3021894 55 * @param sclk SPI Clock pin
elessair 0:f269e3021894 56 * @param name (optional) A string to identify the object
elessair 0:f269e3021894 57 */
elessair 0:f269e3021894 58 SPIHalfDuplex(PinName mosi, PinName miso, PinName sclk);
elessair 0:f269e3021894 59
elessair 0:f269e3021894 60 /** Write to the SPI Slave and return the response
elessair 0:f269e3021894 61 *
elessair 0:f269e3021894 62 * @param value Data to be sent to the SPI slave
elessair 0:f269e3021894 63 *
elessair 0:f269e3021894 64 * @returns
elessair 0:f269e3021894 65 * Response from the SPI slave
elessair 0:f269e3021894 66 */
elessair 0:f269e3021894 67 virtual int write(int value);
elessair 0:f269e3021894 68
elessair 0:f269e3021894 69 /** Set the number of databits expected from the slave, from 4-16
elessair 0:f269e3021894 70 *
elessair 0:f269e3021894 71 * @param sbits Number of expected bits in the slave response
elessair 0:f269e3021894 72 */
elessair 0:f269e3021894 73 void slave_format(int sbits);
elessair 0:f269e3021894 74
elessair 0:f269e3021894 75 protected:
elessair 0:f269e3021894 76 PinName _mosi;
elessair 0:f269e3021894 77 PinName _miso;
elessair 0:f269e3021894 78 int _sbits;
elessair 0:f269e3021894 79 }; // End of class
elessair 0:f269e3021894 80
elessair 0:f269e3021894 81 } // End of namespace mbed
elessair 0:f269e3021894 82
elessair 0:f269e3021894 83 #endif
elessair 0:f269e3021894 84
elessair 0:f269e3021894 85 #endif