Half Duplex Version of SWSPI
Fork of SWSPI by
SWSPI_HD.cpp@1:17d758fe52f8, 2018-06-19 (annotated)
- Committer:
- martinsimpson
- Date:
- Tue Jun 19 09:55:18 2018 +0000
- Revision:
- 1:17d758fe52f8
- Child:
- 2:70039cc8ba02
Fork of SWSPI first commit
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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martinsimpson | 1:17d758fe52f8 | 1 | /* SWSPI, Software SPI library |
martinsimpson | 1:17d758fe52f8 | 2 | * Copyright (c) 2012-2014, David R. Van Wagner, http://techwithdave.blogspot.com |
martinsimpson | 1:17d758fe52f8 | 3 | * |
martinsimpson | 1:17d758fe52f8 | 4 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
martinsimpson | 1:17d758fe52f8 | 5 | * of this software and associated documentation files (the "Software"), to deal |
martinsimpson | 1:17d758fe52f8 | 6 | * in the Software without restriction, including without limitation the rights |
martinsimpson | 1:17d758fe52f8 | 7 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
martinsimpson | 1:17d758fe52f8 | 8 | * copies of the Software, and to permit persons to whom the Software is |
martinsimpson | 1:17d758fe52f8 | 9 | * furnished to do so, subject to the following conditions: |
martinsimpson | 1:17d758fe52f8 | 10 | * |
martinsimpson | 1:17d758fe52f8 | 11 | * The above copyright notice and this permission notice shall be included in |
martinsimpson | 1:17d758fe52f8 | 12 | * all copies or substantial portions of the Software. |
martinsimpson | 1:17d758fe52f8 | 13 | * |
martinsimpson | 1:17d758fe52f8 | 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
martinsimpson | 1:17d758fe52f8 | 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
martinsimpson | 1:17d758fe52f8 | 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
martinsimpson | 1:17d758fe52f8 | 17 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
martinsimpson | 1:17d758fe52f8 | 18 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
martinsimpson | 1:17d758fe52f8 | 19 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
martinsimpson | 1:17d758fe52f8 | 20 | * THE SOFTWARE. |
martinsimpson | 1:17d758fe52f8 | 21 | */ |
martinsimpson | 1:17d758fe52f8 | 22 | |
martinsimpson | 1:17d758fe52f8 | 23 | #include <mbed.h> |
martinsimpson | 1:17d758fe52f8 | 24 | #include "SWSPI_HD.h" |
martinsimpson | 1:17d758fe52f8 | 25 | |
martinsimpson | 1:17d758fe52f8 | 26 | SWSPI_HD::SWSPI_HD(PinName dio_pin, PinName sclk_pin) |
martinsimpson | 1:17d758fe52f8 | 27 | { |
martinsimpson | 1:17d758fe52f8 | 28 | dio = new DigitalInOut(dio_pin); |
martinsimpson | 1:17d758fe52f8 | 29 | sclk = new DigitalOut(sclk_pin); |
martinsimpson | 1:17d758fe52f8 | 30 | format(8); |
martinsimpson | 1:17d758fe52f8 | 31 | frequency(); |
martinsimpson | 1:17d758fe52f8 | 32 | } |
martinsimpson | 1:17d758fe52f8 | 33 | |
martinsimpson | 1:17d758fe52f8 | 34 | SWSPI_HD::~SWSPI_HD() |
martinsimpson | 1:17d758fe52f8 | 35 | { |
martinsimpson | 1:17d758fe52f8 | 36 | delete dio; |
martinsimpson | 1:17d758fe52f8 | 37 | delete sclk; |
martinsimpson | 1:17d758fe52f8 | 38 | } |
martinsimpson | 1:17d758fe52f8 | 39 | |
martinsimpson | 1:17d758fe52f8 | 40 | void SWSPI_HD::format(int bits, int mode) |
martinsimpson | 1:17d758fe52f8 | 41 | { |
martinsimpson | 1:17d758fe52f8 | 42 | this->bits = bits; |
martinsimpson | 1:17d758fe52f8 | 43 | this->mode = mode; |
martinsimpson | 1:17d758fe52f8 | 44 | polarity = (mode >> 1) & 1; |
martinsimpson | 1:17d758fe52f8 | 45 | phase = mode & 1; |
martinsimpson | 1:17d758fe52f8 | 46 | sclk->write(polarity); |
martinsimpson | 1:17d758fe52f8 | 47 | } |
martinsimpson | 1:17d758fe52f8 | 48 | |
martinsimpson | 1:17d758fe52f8 | 49 | void SWSPI_HD::frequency(int hz) |
martinsimpson | 1:17d758fe52f8 | 50 | { |
martinsimpson | 1:17d758fe52f8 | 51 | this->freq = hz; |
martinsimpson | 1:17d758fe52f8 | 52 | } |
martinsimpson | 1:17d758fe52f8 | 53 | |
martinsimpson | 1:17d758fe52f8 | 54 | int SWSPI_HD::write(int value) |
martinsimpson | 1:17d758fe52f8 | 55 | { |
martinsimpson | 1:17d758fe52f8 | 56 | int read = 0; |
martinsimpson | 1:17d758fe52f8 | 57 | for (int bit = bits-1; bit >= 0; --bit) |
martinsimpson | 1:17d758fe52f8 | 58 | { |
martinsimpson | 1:17d758fe52f8 | 59 | dio->output();// set as an OUTPUT |
martinsimpson | 1:17d758fe52f8 | 60 | |
martinsimpson | 1:17d758fe52f8 | 61 | dio->write(((value >> bit) & 0x01) != 0); |
martinsimpson | 1:17d758fe52f8 | 62 | |
martinsimpson | 1:17d758fe52f8 | 63 | dio->input();// set as an INPUT |
martinsimpson | 1:17d758fe52f8 | 64 | |
martinsimpson | 1:17d758fe52f8 | 65 | if (phase == 0) |
martinsimpson | 1:17d758fe52f8 | 66 | { |
martinsimpson | 1:17d758fe52f8 | 67 | |
martinsimpson | 1:17d758fe52f8 | 68 | if (dio->read()) // was miso |
martinsimpson | 1:17d758fe52f8 | 69 | read |= (1 << bit); |
martinsimpson | 1:17d758fe52f8 | 70 | } |
martinsimpson | 1:17d758fe52f8 | 71 | |
martinsimpson | 1:17d758fe52f8 | 72 | sclk->write(!polarity); |
martinsimpson | 1:17d758fe52f8 | 73 | |
martinsimpson | 1:17d758fe52f8 | 74 | wait(1.0/freq/2); |
martinsimpson | 1:17d758fe52f8 | 75 | |
martinsimpson | 1:17d758fe52f8 | 76 | if (phase == 1) |
martinsimpson | 1:17d758fe52f8 | 77 | { |
martinsimpson | 1:17d758fe52f8 | 78 | if (dio->read()) // was miso |
martinsimpson | 1:17d758fe52f8 | 79 | read |= (1 << bit); |
martinsimpson | 1:17d758fe52f8 | 80 | } |
martinsimpson | 1:17d758fe52f8 | 81 | |
martinsimpson | 1:17d758fe52f8 | 82 | sclk->write(polarity); |
martinsimpson | 1:17d758fe52f8 | 83 | |
martinsimpson | 1:17d758fe52f8 | 84 | wait(1.0/freq/2); |
martinsimpson | 1:17d758fe52f8 | 85 | } |
martinsimpson | 1:17d758fe52f8 | 86 | |
martinsimpson | 1:17d758fe52f8 | 87 | return read; |
martinsimpson | 1:17d758fe52f8 | 88 | } |
martinsimpson | 1:17d758fe52f8 | 89 |