forked library from davervw/SWSPI
Dependents: 11u35_usbLocalFilesystem
Fork of SWSPI by
SWSPI.cpp@2:457a920a1223, 2016-03-04 (annotated)
- Committer:
- k4zuki
- Date:
- Fri Mar 04 10:33:56 2016 +0000
- Revision:
- 2:457a920a1223
- Parent:
- 1:0f59aa4b839f
- Child:
- 3:8c6310f2038f
update
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
davervw | 0:6a500a08c7fd | 1 | /* SWSPI, Software SPI library |
davervw | 0:6a500a08c7fd | 2 | * Copyright (c) 2012-2014, David R. Van Wagner, http://techwithdave.blogspot.com |
davervw | 0:6a500a08c7fd | 3 | * |
davervw | 0:6a500a08c7fd | 4 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
davervw | 0:6a500a08c7fd | 5 | * of this software and associated documentation files (the "Software"), to deal |
davervw | 0:6a500a08c7fd | 6 | * in the Software without restriction, including without limitation the rights |
davervw | 0:6a500a08c7fd | 7 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
davervw | 0:6a500a08c7fd | 8 | * copies of the Software, and to permit persons to whom the Software is |
davervw | 0:6a500a08c7fd | 9 | * furnished to do so, subject to the following conditions: |
davervw | 0:6a500a08c7fd | 10 | * |
davervw | 0:6a500a08c7fd | 11 | * The above copyright notice and this permission notice shall be included in |
davervw | 0:6a500a08c7fd | 12 | * all copies or substantial portions of the Software. |
davervw | 0:6a500a08c7fd | 13 | * |
davervw | 0:6a500a08c7fd | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
davervw | 0:6a500a08c7fd | 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
davervw | 0:6a500a08c7fd | 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
davervw | 0:6a500a08c7fd | 17 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
davervw | 0:6a500a08c7fd | 18 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
davervw | 0:6a500a08c7fd | 19 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
davervw | 0:6a500a08c7fd | 20 | * THE SOFTWARE. |
davervw | 0:6a500a08c7fd | 21 | */ |
davervw | 0:6a500a08c7fd | 22 | |
davervw | 0:6a500a08c7fd | 23 | #include "SWSPI.h" |
davervw | 0:6a500a08c7fd | 24 | |
k4zuki | 1:0f59aa4b839f | 25 | SWSPI::SWSPI(PinName mosi_pin, PinName miso_pin, PinName sclk_pin):_fast(false) |
davervw | 0:6a500a08c7fd | 26 | { |
k4zuki | 2:457a920a1223 | 27 | mosi = new DigitalOut(mosi_pin); |
k4zuki | 2:457a920a1223 | 28 | miso = new DigitalIn(miso_pin); |
k4zuki | 2:457a920a1223 | 29 | sclk = new DigitalOut(sclk_pin); |
davervw | 0:6a500a08c7fd | 30 | format(8); |
davervw | 0:6a500a08c7fd | 31 | frequency(); |
davervw | 0:6a500a08c7fd | 32 | } |
davervw | 0:6a500a08c7fd | 33 | |
davervw | 0:6a500a08c7fd | 34 | SWSPI::~SWSPI() |
davervw | 0:6a500a08c7fd | 35 | { |
davervw | 0:6a500a08c7fd | 36 | delete mosi; |
davervw | 0:6a500a08c7fd | 37 | delete miso; |
davervw | 0:6a500a08c7fd | 38 | delete sclk; |
davervw | 0:6a500a08c7fd | 39 | } |
davervw | 0:6a500a08c7fd | 40 | |
davervw | 0:6a500a08c7fd | 41 | void SWSPI::format(int bits, int mode) |
davervw | 0:6a500a08c7fd | 42 | { |
davervw | 0:6a500a08c7fd | 43 | this->bits = bits; |
davervw | 0:6a500a08c7fd | 44 | this->mode = mode; |
davervw | 0:6a500a08c7fd | 45 | polarity = (mode >> 1) & 1; |
davervw | 0:6a500a08c7fd | 46 | phase = mode & 1; |
davervw | 0:6a500a08c7fd | 47 | sclk->write(polarity); |
davervw | 0:6a500a08c7fd | 48 | } |
davervw | 0:6a500a08c7fd | 49 | |
davervw | 0:6a500a08c7fd | 50 | void SWSPI::frequency(int hz) |
davervw | 0:6a500a08c7fd | 51 | { |
davervw | 0:6a500a08c7fd | 52 | this->freq = hz; |
k4zuki | 1:0f59aa4b839f | 53 | _fast = (hz >= 1000000) ? true : false; |
davervw | 0:6a500a08c7fd | 54 | } |
davervw | 0:6a500a08c7fd | 55 | |
k4zuki | 1:0f59aa4b839f | 56 | #pragma Otime |
k4zuki | 1:0f59aa4b839f | 57 | |
davervw | 0:6a500a08c7fd | 58 | int SWSPI::write(int value) |
davervw | 0:6a500a08c7fd | 59 | { |
k4zuki | 1:0f59aa4b839f | 60 | |
davervw | 0:6a500a08c7fd | 61 | int read = 0; |
k4zuki | 1:0f59aa4b839f | 62 | if (_fast) { |
k4zuki | 1:0f59aa4b839f | 63 | read = fast_write(value); |
k4zuki | 2:457a920a1223 | 64 | } else { |
k4zuki | 2:457a920a1223 | 65 | for (int bit = bits-1; bit >= 0; --bit) { |
k4zuki | 2:457a920a1223 | 66 | mosi->write(((value >> bit) & 0x01) != 0); |
davervw | 0:6a500a08c7fd | 67 | |
k4zuki | 2:457a920a1223 | 68 | if (phase == 0) { |
k4zuki | 2:457a920a1223 | 69 | if (miso->read()) |
k4zuki | 2:457a920a1223 | 70 | read |= (1 << bit); |
k4zuki | 2:457a920a1223 | 71 | } |
k4zuki | 2:457a920a1223 | 72 | |
k4zuki | 2:457a920a1223 | 73 | sclk->write(!polarity); |
davervw | 0:6a500a08c7fd | 74 | |
k4zuki | 2:457a920a1223 | 75 | wait_us(1000000/freq/2); |
davervw | 0:6a500a08c7fd | 76 | |
k4zuki | 2:457a920a1223 | 77 | if (phase == 1) { |
k4zuki | 2:457a920a1223 | 78 | if (miso->read()) |
k4zuki | 2:457a920a1223 | 79 | read |= (1 << bit); |
k4zuki | 2:457a920a1223 | 80 | } |
k4zuki | 2:457a920a1223 | 81 | |
k4zuki | 2:457a920a1223 | 82 | sclk->write(polarity); |
k4zuki | 2:457a920a1223 | 83 | |
k4zuki | 2:457a920a1223 | 84 | wait_us(1000000/freq/2); |
davervw | 0:6a500a08c7fd | 85 | } |
davervw | 0:6a500a08c7fd | 86 | } |
k4zuki | 1:0f59aa4b839f | 87 | |
davervw | 0:6a500a08c7fd | 88 | return read; |
davervw | 0:6a500a08c7fd | 89 | } |
davervw | 0:6a500a08c7fd | 90 | |
k4zuki | 1:0f59aa4b839f | 91 | uint8_t SWSPI::fast_write(uint8_t value) |
k4zuki | 1:0f59aa4b839f | 92 | { |
k4zuki | 1:0f59aa4b839f | 93 | uint8_t data = 0; |
k4zuki | 1:0f59aa4b839f | 94 | for(uint8_t mask = 0x80; mask; mask >>= 1) { |
k4zuki | 1:0f59aa4b839f | 95 | mosi->write((value & mask) ? 1 : 0); |
k4zuki | 1:0f59aa4b839f | 96 | if (miso->read()) { |
k4zuki | 1:0f59aa4b839f | 97 | data |= mask; |
k4zuki | 1:0f59aa4b839f | 98 | } |
k4zuki | 1:0f59aa4b839f | 99 | sclk->write(1); |
k4zuki | 1:0f59aa4b839f | 100 | sclk->write(0); |
k4zuki | 1:0f59aa4b839f | 101 | } |
k4zuki | 1:0f59aa4b839f | 102 | return data; |
k4zuki | 1:0f59aa4b839f | 103 | } |
k4zuki | 1:0f59aa4b839f | 104 |