kushagra brahmbhatt / IoT_Security

IoT Home Alarm System

Dependents:   IoTBurglar_and_Fire_AlarmSystem

SPI.h@0:2f388b030837, 2016-04-29 (annotated)

Committer:
kbrahmbhatt6
Date:
Fri Apr 29 06:59:59 2016 +0000
Revision:
0:2f388b030837
1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
kbrahmbhatt6 0:2f388b030837 1 /* mbed Microcontroller Library
kbrahmbhatt6 0:2f388b030837 2 * Copyright (c) 2006-2013 ARM Limited
kbrahmbhatt6 0:2f388b030837 3 *
kbrahmbhatt6 0:2f388b030837 4 * Licensed under the Apache License, Version 2.0 (the "License");
kbrahmbhatt6 0:2f388b030837 5 * you may not use this file except in compliance with the License.
kbrahmbhatt6 0:2f388b030837 6 * You may obtain a copy of the License at
kbrahmbhatt6 0:2f388b030837 7 *
kbrahmbhatt6 0:2f388b030837 8 * http://www.apache.org/licenses/LICENSE-2.0
kbrahmbhatt6 0:2f388b030837 9 *
kbrahmbhatt6 0:2f388b030837 10 * Unless required by applicable law or agreed to in writing, software
kbrahmbhatt6 0:2f388b030837 11 * distributed under the License is distributed on an "AS IS" BASIS,
kbrahmbhatt6 0:2f388b030837 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
kbrahmbhatt6 0:2f388b030837 13 * See the License for the specific language governing permissions and
kbrahmbhatt6 0:2f388b030837 14 * limitations under the License.
kbrahmbhatt6 0:2f388b030837 15 */
kbrahmbhatt6 0:2f388b030837 16 #ifndef MBED_SPI_H
kbrahmbhatt6 0:2f388b030837 17 #define MBED_SPI_H
kbrahmbhatt6 0:2f388b030837 18
kbrahmbhatt6 0:2f388b030837 19 #include "platform.h"
kbrahmbhatt6 0:2f388b030837 20
kbrahmbhatt6 0:2f388b030837 21 #if DEVICE_SPI
kbrahmbhatt6 0:2f388b030837 22
kbrahmbhatt6 0:2f388b030837 23 #include "spi_api.h"
kbrahmbhatt6 0:2f388b030837 24
kbrahmbhatt6 0:2f388b030837 25 namespace mbed {
kbrahmbhatt6 0:2f388b030837 26
kbrahmbhatt6 0:2f388b030837 27 /** A SPI Master, used for communicating with SPI slave devices
kbrahmbhatt6 0:2f388b030837 28 *
kbrahmbhatt6 0:2f388b030837 29 * The default format is set to 8-bits, mode 0, and a clock frequency of 1MHz
kbrahmbhatt6 0:2f388b030837 30 *
kbrahmbhatt6 0:2f388b030837 31 * Most SPI devices will also require Chip Select and Reset signals. These
kbrahmbhatt6 0:2f388b030837 32 * can be controlled using <DigitalOut> pins
kbrahmbhatt6 0:2f388b030837 33 *
kbrahmbhatt6 0:2f388b030837 34 * Example:
kbrahmbhatt6 0:2f388b030837 35 * @code
kbrahmbhatt6 0:2f388b030837 36 * // Send a byte to a SPI slave, and record the response
kbrahmbhatt6 0:2f388b030837 37 *
kbrahmbhatt6 0:2f388b030837 38 * #include "mbed.h"
kbrahmbhatt6 0:2f388b030837 39 *
kbrahmbhatt6 0:2f388b030837 40 * SPI device(p5, p6, p7); // mosi, miso, sclk
kbrahmbhatt6 0:2f388b030837 41 *
kbrahmbhatt6 0:2f388b030837 42 * int main() {
kbrahmbhatt6 0:2f388b030837 43 * int response = device.write(0xFF);
kbrahmbhatt6 0:2f388b030837 44 * }
kbrahmbhatt6 0:2f388b030837 45 * @endcode
kbrahmbhatt6 0:2f388b030837 46 */
kbrahmbhatt6 0:2f388b030837 47 class SPI {
kbrahmbhatt6 0:2f388b030837 48
kbrahmbhatt6 0:2f388b030837 49 public:
kbrahmbhatt6 0:2f388b030837 50
kbrahmbhatt6 0:2f388b030837 51 /** Create a SPI master connected to the specified pins
kbrahmbhatt6 0:2f388b030837 52 *
kbrahmbhatt6 0:2f388b030837 53 * Pin Options:
kbrahmbhatt6 0:2f388b030837 54 * (5, 6, 7) or (11, 12, 13)
kbrahmbhatt6 0:2f388b030837 55 *
kbrahmbhatt6 0:2f388b030837 56 * mosi or miso can be specfied as NC if not used
kbrahmbhatt6 0:2f388b030837 57 *
kbrahmbhatt6 0:2f388b030837 58 * @param mosi SPI Master Out, Slave In pin
kbrahmbhatt6 0:2f388b030837 59 * @param miso SPI Master In, Slave Out pin
kbrahmbhatt6 0:2f388b030837 60 * @param sclk SPI Clock pin
kbrahmbhatt6 0:2f388b030837 61 */
kbrahmbhatt6 0:2f388b030837 62 SPI(PinName mosi, PinName miso, PinName sclk, PinName _unused=NC);
kbrahmbhatt6 0:2f388b030837 63
kbrahmbhatt6 0:2f388b030837 64 /** Configure the data transmission format
kbrahmbhatt6 0:2f388b030837 65 *
kbrahmbhatt6 0:2f388b030837 66 * @param bits Number of bits per SPI frame (4 - 16)
kbrahmbhatt6 0:2f388b030837 67 * @param mode Clock polarity and phase mode (0 - 3)
kbrahmbhatt6 0:2f388b030837 68 *
kbrahmbhatt6 0:2f388b030837 69 * @code
kbrahmbhatt6 0:2f388b030837 70 * mode | POL PHA
kbrahmbhatt6 0:2f388b030837 71 * -----+--------
kbrahmbhatt6 0:2f388b030837 72 * 0 | 0 0
kbrahmbhatt6 0:2f388b030837 73 * 1 | 0 1
kbrahmbhatt6 0:2f388b030837 74 * 2 | 1 0
kbrahmbhatt6 0:2f388b030837 75 * 3 | 1 1
kbrahmbhatt6 0:2f388b030837 76 * @endcode
kbrahmbhatt6 0:2f388b030837 77 */
kbrahmbhatt6 0:2f388b030837 78 void format(int bits, int mode = 0);
kbrahmbhatt6 0:2f388b030837 79
kbrahmbhatt6 0:2f388b030837 80 /** Set the spi bus clock frequency
kbrahmbhatt6 0:2f388b030837 81 *
kbrahmbhatt6 0:2f388b030837 82 * @param hz SCLK frequency in hz (default = 1MHz)
kbrahmbhatt6 0:2f388b030837 83 */
kbrahmbhatt6 0:2f388b030837 84 void frequency(int hz = 1000000);
kbrahmbhatt6 0:2f388b030837 85
kbrahmbhatt6 0:2f388b030837 86 /** Write to the SPI Slave and return the response
kbrahmbhatt6 0:2f388b030837 87 *
kbrahmbhatt6 0:2f388b030837 88 * @param value Data to be sent to the SPI slave
kbrahmbhatt6 0:2f388b030837 89 *
kbrahmbhatt6 0:2f388b030837 90 * @returns
kbrahmbhatt6 0:2f388b030837 91 * Response from the SPI slave
kbrahmbhatt6 0:2f388b030837 92 */
kbrahmbhatt6 0:2f388b030837 93 virtual int write(int value);
kbrahmbhatt6 0:2f388b030837 94
kbrahmbhatt6 0:2f388b030837 95 protected:
kbrahmbhatt6 0:2f388b030837 96 spi_t _spi;
kbrahmbhatt6 0:2f388b030837 97
kbrahmbhatt6 0:2f388b030837 98 void aquire(void);
kbrahmbhatt6 0:2f388b030837 99 static SPI *_owner;
kbrahmbhatt6 0:2f388b030837 100 int _bits;
kbrahmbhatt6 0:2f388b030837 101 int _mode;
kbrahmbhatt6 0:2f388b030837 102 int _hz;
kbrahmbhatt6 0:2f388b030837 103 };
kbrahmbhatt6 0:2f388b030837 104
kbrahmbhatt6 0:2f388b030837 105 } // namespace mbed
kbrahmbhatt6 0:2f388b030837 106
kbrahmbhatt6 0:2f388b030837 107 #endif
kbrahmbhatt6 0:2f388b030837 108
kbrahmbhatt6 0:2f388b030837 109 #endif