Andrew Boyson / Mbed 2 deprecated iot

Backing up an unused program in case of future need

Dependencies:   mbed

1-wire.cpp@4:e076884ef8bd, 2016-05-03 (annotated)

Committer:
andrewboyson
Date:
Tue May 03 09:23:26 2016 +0000
Revision:
4:e076884ef8bd
Child:
5:6226f3c566ef
Added 1-wire

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 4:e076884ef8bd 1 #include "mbed.h"
andrewboyson 4:e076884ef8bd 2 #include "log.h"
andrewboyson 4:e076884ef8bd 3 #include "io.h"
andrewboyson 4:e076884ef8bd 4
andrewboyson 4:e076884ef8bd 5 //Bus zone
andrewboyson 4:e076884ef8bd 6 //========
andrewboyson 4:e076884ef8bd 7 static DigitalInOut pin(p25, PIN_INPUT, PullUp, 0);
andrewboyson 4:e076884ef8bd 8
andrewboyson 4:e076884ef8bd 9
andrewboyson 4:e076884ef8bd 10 static int busvalue;
andrewboyson 4:e076884ef8bd 11
andrewboyson 4:e076884ef8bd 12 //Delays
andrewboyson 4:e076884ef8bd 13 #define ATTACH_DELAY 7
andrewboyson 4:e076884ef8bd 14 #define INITIAL_DELAY 100
andrewboyson 4:e076884ef8bd 15 #define RESET_BUS_LOW_DELAY 480
andrewboyson 4:e076884ef8bd 16 #define READ_PRESENCE_DELAY 70
andrewboyson 4:e076884ef8bd 17 #define RESET_RELEASE_DELAY 410
andrewboyson 4:e076884ef8bd 18 #define WRITE_0_BUS_LOW_DELAY 60
andrewboyson 4:e076884ef8bd 19 #define WRITE_0_RELEASE_DELAY 10
andrewboyson 4:e076884ef8bd 20 #define WRITE_1_BUS_LOW_DELAY 6
andrewboyson 4:e076884ef8bd 21 #define WRITE_1_RELEASE_DELAY 64
andrewboyson 4:e076884ef8bd 22 #define READ_BIT_BUS_LOW_DELAY 6
andrewboyson 4:e076884ef8bd 23 #define READ_BIT_DELAY 9
andrewboyson 4:e076884ef8bd 24 #define READ_BIT_RELEASE_DELAY 55
andrewboyson 4:e076884ef8bd 25 #define BUS_TIMEOUT_MS 1000
andrewboyson 4:e076884ef8bd 26
andrewboyson 4:e076884ef8bd 27 static int busbusy = false; //Set whenever an operation starts; reset by finishbus interrupt;
andrewboyson 4:e076884ef8bd 28 static Timer busbusytimer;
andrewboyson 4:e076884ef8bd 29
andrewboyson 4:e076884ef8bd 30 static void buslow (void) { pin = 0; pin.output(); }
andrewboyson 4:e076884ef8bd 31 static Timeout startbuslow;
andrewboyson 4:e076884ef8bd 32 static void busfree(void) { pin.input (); }
andrewboyson 4:e076884ef8bd 33 static Timeout startbusfree;
andrewboyson 4:e076884ef8bd 34 static void bushigh(void) { pin = 1; pin.output(); }
andrewboyson 4:e076884ef8bd 35 static Timeout startbushigh;
andrewboyson 4:e076884ef8bd 36 static void busread(void) { busvalue = pin; }
andrewboyson 4:e076884ef8bd 37 static Timeout startbusread;
andrewboyson 4:e076884ef8bd 38 static void busidle(void) { pin.input (); busbusy = false; }
andrewboyson 4:e076884ef8bd 39 static Timeout startbusidle;
andrewboyson 4:e076884ef8bd 40
andrewboyson 4:e076884ef8bd 41 static void reset()
andrewboyson 4:e076884ef8bd 42 {
andrewboyson 4:e076884ef8bd 43 busbusy = true;
andrewboyson 4:e076884ef8bd 44 int delay = INITIAL_DELAY - ATTACH_DELAY; startbuslow.attach_us(&buslow, delay);
andrewboyson 4:e076884ef8bd 45 delay += RESET_BUS_LOW_DELAY - ATTACH_DELAY; startbusfree.attach_us(&busfree, delay);
andrewboyson 4:e076884ef8bd 46 delay += READ_PRESENCE_DELAY - ATTACH_DELAY; startbusread.attach_us(&busread, delay);
andrewboyson 4:e076884ef8bd 47 delay += RESET_RELEASE_DELAY - ATTACH_DELAY; startbusidle.attach_us(&busidle, delay);
andrewboyson 4:e076884ef8bd 48 }
andrewboyson 4:e076884ef8bd 49 static void writebit(int bit, int msToPullUp)
andrewboyson 4:e076884ef8bd 50 {
andrewboyson 4:e076884ef8bd 51 busbusy = true;
andrewboyson 4:e076884ef8bd 52 int delay = INITIAL_DELAY - ATTACH_DELAY;
andrewboyson 4:e076884ef8bd 53 startbuslow.attach_us(&buslow, delay);
andrewboyson 4:e076884ef8bd 54 delay += bit ? WRITE_1_BUS_LOW_DELAY : WRITE_0_BUS_LOW_DELAY;
andrewboyson 4:e076884ef8bd 55 delay -= ATTACH_DELAY;
andrewboyson 4:e076884ef8bd 56 if (msToPullUp)
andrewboyson 4:e076884ef8bd 57 {
andrewboyson 4:e076884ef8bd 58 startbushigh.attach_us(&bushigh, delay);
andrewboyson 4:e076884ef8bd 59 delay += msToPullUp * 1000 - ATTACH_DELAY;
andrewboyson 4:e076884ef8bd 60 }
andrewboyson 4:e076884ef8bd 61 else
andrewboyson 4:e076884ef8bd 62 {
andrewboyson 4:e076884ef8bd 63 startbusfree.attach_us(&busfree, delay);
andrewboyson 4:e076884ef8bd 64 delay += bit ? WRITE_1_RELEASE_DELAY : WRITE_0_RELEASE_DELAY;
andrewboyson 4:e076884ef8bd 65 delay -= ATTACH_DELAY;
andrewboyson 4:e076884ef8bd 66 }
andrewboyson 4:e076884ef8bd 67 startbusidle.attach_us(&busidle, delay);
andrewboyson 4:e076884ef8bd 68 }
andrewboyson 4:e076884ef8bd 69 static void initiatebitread()
andrewboyson 4:e076884ef8bd 70 {
andrewboyson 4:e076884ef8bd 71 busbusy = true;
andrewboyson 4:e076884ef8bd 72 int delay = INITIAL_DELAY - ATTACH_DELAY; startbuslow.attach_us(&buslow, delay);
andrewboyson 4:e076884ef8bd 73 delay += READ_BIT_BUS_LOW_DELAY - ATTACH_DELAY; startbusfree.attach_us(&busfree, delay);
andrewboyson 4:e076884ef8bd 74 delay += READ_BIT_DELAY - ATTACH_DELAY; startbusread.attach_us(&busread, delay);
andrewboyson 4:e076884ef8bd 75 delay += READ_BIT_RELEASE_DELAY - ATTACH_DELAY; startbusidle.attach_us(&busidle, delay);
andrewboyson 4:e076884ef8bd 76 }
andrewboyson 4:e076884ef8bd 77
andrewboyson 4:e076884ef8bd 78 //Exchange zone
andrewboyson 4:e076884ef8bd 79 //=============
andrewboyson 4:e076884ef8bd 80 #define XCHG_IDLE 0
andrewboyson 4:e076884ef8bd 81 #define XCHG_RESET 1
andrewboyson 4:e076884ef8bd 82 #define XCHG_WRITE 2
andrewboyson 4:e076884ef8bd 83 #define XCHG_READ 3
andrewboyson 4:e076884ef8bd 84 #define XCHG_PULLUP 4
andrewboyson 4:e076884ef8bd 85 static int xchgstate = XCHG_IDLE;
andrewboyson 4:e076884ef8bd 86
andrewboyson 4:e076884ef8bd 87 static int lensend = 0;
andrewboyson 4:e076884ef8bd 88 static int lenrecv = 0;
andrewboyson 4:e076884ef8bd 89 static char* psend = NULL;
andrewboyson 4:e076884ef8bd 90 static char* precv = NULL;
andrewboyson 4:e076884ef8bd 91 static int pullupms = 0;
andrewboyson 4:e076884ef8bd 92
andrewboyson 4:e076884ef8bd 93 static void resetBitPosition(int* pByteIndex, char* pBitMask)
andrewboyson 4:e076884ef8bd 94 {
andrewboyson 4:e076884ef8bd 95 *pBitMask = 1;
andrewboyson 4:e076884ef8bd 96 *pByteIndex = 0;
andrewboyson 4:e076884ef8bd 97 }
andrewboyson 4:e076884ef8bd 98 static void incrementBitPosition(int* pByteIndex, char* pBitMask)
andrewboyson 4:e076884ef8bd 99 {
andrewboyson 4:e076884ef8bd 100 *pBitMask <<= 1;
andrewboyson 4:e076884ef8bd 101 if (!*pBitMask)
andrewboyson 4:e076884ef8bd 102 {
andrewboyson 4:e076884ef8bd 103 *pBitMask = 1;
andrewboyson 4:e076884ef8bd 104 *pByteIndex += 1;
andrewboyson 4:e076884ef8bd 105 }
andrewboyson 4:e076884ef8bd 106 }
andrewboyson 4:e076884ef8bd 107
andrewboyson 4:e076884ef8bd 108 int getBitAtPosition(int byteIndex, char bitMask)
andrewboyson 4:e076884ef8bd 109 {
andrewboyson 4:e076884ef8bd 110 return psend[byteIndex] & bitMask;
andrewboyson 4:e076884ef8bd 111 }
andrewboyson 4:e076884ef8bd 112 void setBitAtPosition(int byteIndex, char bitMask, int bit)
andrewboyson 4:e076884ef8bd 113 {
andrewboyson 4:e076884ef8bd 114 if (bit) precv[byteIndex] |= bitMask;
andrewboyson 4:e076884ef8bd 115 }
andrewboyson 4:e076884ef8bd 116 int moreBitsToRead(int byteIndex)
andrewboyson 4:e076884ef8bd 117 {
andrewboyson 4:e076884ef8bd 118 return byteIndex < lenrecv;
andrewboyson 4:e076884ef8bd 119 }
andrewboyson 4:e076884ef8bd 120 int moreBitsToWrite(int byteIndex)
andrewboyson 4:e076884ef8bd 121 {
andrewboyson 4:e076884ef8bd 122 return byteIndex < lensend;
andrewboyson 4:e076884ef8bd 123 }
andrewboyson 4:e076884ef8bd 124 int OneWireInit()
andrewboyson 4:e076884ef8bd 125 {
andrewboyson 4:e076884ef8bd 126 startbuslow.detach();
andrewboyson 4:e076884ef8bd 127 startbushigh.detach();
andrewboyson 4:e076884ef8bd 128 startbusfree.detach();
andrewboyson 4:e076884ef8bd 129 startbusread.detach();
andrewboyson 4:e076884ef8bd 130 startbusidle.detach();
andrewboyson 4:e076884ef8bd 131 busidle();
andrewboyson 4:e076884ef8bd 132 xchgstate = XCHG_IDLE;
andrewboyson 4:e076884ef8bd 133 busbusytimer.stop();
andrewboyson 4:e076884ef8bd 134 busbusytimer.reset();
andrewboyson 4:e076884ef8bd 135 return 0;
andrewboyson 4:e076884ef8bd 136 }
andrewboyson 4:e076884ef8bd 137 int OneWireBusy()
andrewboyson 4:e076884ef8bd 138 {
andrewboyson 4:e076884ef8bd 139 return xchgstate;
andrewboyson 4:e076884ef8bd 140 }
andrewboyson 4:e076884ef8bd 141 void OneWireExchange(int lenBytesToSend, int lenBytesToRecv, char *pBytesToSend, char *pBytesToRecv, int msToPullUp)
andrewboyson 4:e076884ef8bd 142 {
andrewboyson 4:e076884ef8bd 143 lensend = lenBytesToSend;
andrewboyson 4:e076884ef8bd 144 lenrecv = lenBytesToRecv;
andrewboyson 4:e076884ef8bd 145 psend = pBytesToSend;
andrewboyson 4:e076884ef8bd 146 precv = pBytesToRecv;
andrewboyson 4:e076884ef8bd 147 pullupms = msToPullUp;
andrewboyson 4:e076884ef8bd 148 xchgstate = XCHG_RESET;
andrewboyson 4:e076884ef8bd 149 reset();
andrewboyson 4:e076884ef8bd 150 }
andrewboyson 4:e076884ef8bd 151 int OneWireMain()
andrewboyson 4:e076884ef8bd 152 {
andrewboyson 4:e076884ef8bd 153 static int byteindex;
andrewboyson 4:e076884ef8bd 154 static char bitmask;
andrewboyson 4:e076884ef8bd 155
andrewboyson 4:e076884ef8bd 156 if (busbusy)
andrewboyson 4:e076884ef8bd 157 {
andrewboyson 4:e076884ef8bd 158 busbusytimer.start();
andrewboyson 4:e076884ef8bd 159 if (busbusytimer.read_ms() > BUS_TIMEOUT_MS)
andrewboyson 4:e076884ef8bd 160 {
andrewboyson 4:e076884ef8bd 161 LogCrLf("1-wire bus timed out so protocol has been reset to idle.");
andrewboyson 4:e076884ef8bd 162 OneWireInit();
andrewboyson 4:e076884ef8bd 163 }
andrewboyson 4:e076884ef8bd 164 return 0;
andrewboyson 4:e076884ef8bd 165 }
andrewboyson 4:e076884ef8bd 166 else
andrewboyson 4:e076884ef8bd 167 {
andrewboyson 4:e076884ef8bd 168 busbusytimer.stop();
andrewboyson 4:e076884ef8bd 169 busbusytimer.reset();
andrewboyson 4:e076884ef8bd 170 }
andrewboyson 4:e076884ef8bd 171
andrewboyson 4:e076884ef8bd 172 switch(xchgstate)
andrewboyson 4:e076884ef8bd 173 {
andrewboyson 4:e076884ef8bd 174 case XCHG_IDLE:
andrewboyson 4:e076884ef8bd 175 break;
andrewboyson 4:e076884ef8bd 176 case XCHG_RESET:
andrewboyson 4:e076884ef8bd 177 if (busvalue)
andrewboyson 4:e076884ef8bd 178 {
andrewboyson 4:e076884ef8bd 179 LogCrLf("No 1-wire device presence detected on the bus");
andrewboyson 4:e076884ef8bd 180 xchgstate = XCHG_IDLE;
andrewboyson 4:e076884ef8bd 181 }
andrewboyson 4:e076884ef8bd 182 else
andrewboyson 4:e076884ef8bd 183 {
andrewboyson 4:e076884ef8bd 184 resetBitPosition(&byteindex, &bitmask);
andrewboyson 4:e076884ef8bd 185 xchgstate = XCHG_WRITE;
andrewboyson 4:e076884ef8bd 186 }
andrewboyson 4:e076884ef8bd 187 break;
andrewboyson 4:e076884ef8bd 188 case XCHG_WRITE:
andrewboyson 4:e076884ef8bd 189 if (moreBitsToWrite(byteindex))
andrewboyson 4:e076884ef8bd 190 {
andrewboyson 4:e076884ef8bd 191 int bit = getBitAtPosition(byteindex, bitmask);
andrewboyson 4:e076884ef8bd 192 incrementBitPosition(&byteindex, &bitmask);
andrewboyson 4:e076884ef8bd 193 if (moreBitsToWrite(byteindex)) writebit(bit, 0);
andrewboyson 4:e076884ef8bd 194 else writebit(bit, pullupms);
andrewboyson 4:e076884ef8bd 195 }
andrewboyson 4:e076884ef8bd 196 else
andrewboyson 4:e076884ef8bd 197 {
andrewboyson 4:e076884ef8bd 198 resetBitPosition(&byteindex, &bitmask);
andrewboyson 4:e076884ef8bd 199 if (moreBitsToRead(byteindex))
andrewboyson 4:e076884ef8bd 200 {
andrewboyson 4:e076884ef8bd 201 initiatebitread();
andrewboyson 4:e076884ef8bd 202 xchgstate = XCHG_READ;
andrewboyson 4:e076884ef8bd 203
andrewboyson 4:e076884ef8bd 204 }
andrewboyson 4:e076884ef8bd 205 else
andrewboyson 4:e076884ef8bd 206 {
andrewboyson 4:e076884ef8bd 207 xchgstate = XCHG_IDLE;
andrewboyson 4:e076884ef8bd 208 }
andrewboyson 4:e076884ef8bd 209 }
andrewboyson 4:e076884ef8bd 210 break;
andrewboyson 4:e076884ef8bd 211 case XCHG_READ:
andrewboyson 4:e076884ef8bd 212 setBitAtPosition(byteindex, bitmask, busvalue);
andrewboyson 4:e076884ef8bd 213 incrementBitPosition(&byteindex, &bitmask);
andrewboyson 4:e076884ef8bd 214 if (moreBitsToRead(byteindex))
andrewboyson 4:e076884ef8bd 215 {
andrewboyson 4:e076884ef8bd 216 initiatebitread();
andrewboyson 4:e076884ef8bd 217 }
andrewboyson 4:e076884ef8bd 218 else
andrewboyson 4:e076884ef8bd 219 {
andrewboyson 4:e076884ef8bd 220 xchgstate = XCHG_IDLE;
andrewboyson 4:e076884ef8bd 221 }
andrewboyson 4:e076884ef8bd 222 break;
andrewboyson 4:e076884ef8bd 223 default:
andrewboyson 4:e076884ef8bd 224 LogF("Unknown xchgstate %d\r\n", xchgstate);
andrewboyson 4:e076884ef8bd 225 return -1;
andrewboyson 4:e076884ef8bd 226 }
andrewboyson 4:e076884ef8bd 227 return 0;
andrewboyson 4:e076884ef8bd 228 }