forked library from davervw/SWSPI
Dependents: 11u35_usbLocalFilesystem
Fork of SWSPI by
SWSPI.cpp
- Committer:
- k4zuki
- Date:
- 2016-03-04
- Revision:
- 2:457a920a1223
- Parent:
- 1:0f59aa4b839f
- Child:
- 3:8c6310f2038f
File content as of revision 2:457a920a1223:
/* SWSPI, Software SPI library * Copyright (c) 2012-2014, David R. Van Wagner, http://techwithdave.blogspot.com * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "SWSPI.h" SWSPI::SWSPI(PinName mosi_pin, PinName miso_pin, PinName sclk_pin):_fast(false) { mosi = new DigitalOut(mosi_pin); miso = new DigitalIn(miso_pin); sclk = new DigitalOut(sclk_pin); format(8); frequency(); } SWSPI::~SWSPI() { delete mosi; delete miso; delete sclk; } void SWSPI::format(int bits, int mode) { this->bits = bits; this->mode = mode; polarity = (mode >> 1) & 1; phase = mode & 1; sclk->write(polarity); } void SWSPI::frequency(int hz) { this->freq = hz; _fast = (hz >= 1000000) ? true : false; } #pragma Otime int SWSPI::write(int value) { int read = 0; if (_fast) { read = fast_write(value); } else { for (int bit = bits-1; bit >= 0; --bit) { mosi->write(((value >> bit) & 0x01) != 0); if (phase == 0) { if (miso->read()) read |= (1 << bit); } sclk->write(!polarity); wait_us(1000000/freq/2); if (phase == 1) { if (miso->read()) read |= (1 << bit); } sclk->write(polarity); wait_us(1000000/freq/2); } } return read; } uint8_t SWSPI::fast_write(uint8_t value) { uint8_t data = 0; for(uint8_t mask = 0x80; mask; mask >>= 1) { mosi->write((value & mask) ? 1 : 0); if (miso->read()) { data |= mask; } sclk->write(1); sclk->write(0); } return data; }