Andrew Boyson / Mbed 2 deprecated iot

Backing up an unused program in case of future need

Dependencies:   mbed

1-wire.cpp@8:45a0205a298f, 2018-12-06 (annotated)

Committer:
andrewboyson
Date:
Thu Dec 06 11:40:19 2018 +0000
Revision:
8:45a0205a298f
Parent:
7:024ace6d943c 
Backing up

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 6:be97d38e0b01 1 #include "mbed.h"
andrewboyson 6:be97d38e0b01 2 #include "log.h"
andrewboyson 6:be97d38e0b01 3 #include "io.h"
andrewboyson 6:be97d38e0b01 4 #include "1-wire.h"
andrewboyson 4:e076884ef8bd 5
andrewboyson 7:024ace6d943c 6 #define DEBUG false //Set to true to add debug messages to the log
andrewboyson 7:024ace6d943c 7
andrewboyson 4:e076884ef8bd 8 //Bus zone
andrewboyson 4:e076884ef8bd 9 //========
andrewboyson 4:e076884ef8bd 10 static DigitalInOut pin(p25, PIN_INPUT, PullUp, 0);
andrewboyson 4:e076884ef8bd 11
andrewboyson 6:be97d38e0b01 12 static volatile int busvalue;
andrewboyson 4:e076884ef8bd 13
andrewboyson 6:be97d38e0b01 14 static Timer timer;
andrewboyson 6:be97d38e0b01 15 static Timer busytimer;
andrewboyson 4:e076884ef8bd 16
andrewboyson 4:e076884ef8bd 17 //Delays
andrewboyson 5:6226f3c566ef 18 #define ATTACH_US 7
andrewboyson 5:6226f3c566ef 19 #define INITIAL_US 100
andrewboyson 5:6226f3c566ef 20 #define RESET_BUS_LOW_US 480
andrewboyson 5:6226f3c566ef 21 #define READ_PRESENCE_US 70
andrewboyson 5:6226f3c566ef 22 #define RESET_RELEASE_US 410
andrewboyson 5:6226f3c566ef 23 #define WRITE_0_BUS_LOW_US 60
andrewboyson 5:6226f3c566ef 24 #define WRITE_0_RELEASE_US 10
andrewboyson 5:6226f3c566ef 25 #define WRITE_1_BUS_LOW_US 6
andrewboyson 5:6226f3c566ef 26 #define WRITE_1_RELEASE_US 64
andrewboyson 5:6226f3c566ef 27 #define READ_BIT_BUS_LOW_US 6
andrewboyson 5:6226f3c566ef 28 #define READ_BIT_US 9
andrewboyson 5:6226f3c566ef 29 #define READ_BIT_RELEASE_US 55
andrewboyson 6:be97d38e0b01 30 #define BUS_TIMEOUT_MS 5000
andrewboyson 4:e076884ef8bd 31
andrewboyson 6:be97d38e0b01 32 static void buslow (void) { pin.output(); pin = 0; }
andrewboyson 6:be97d38e0b01 33 static void busfree(void) { pin.input (); }
andrewboyson 6:be97d38e0b01 34 static void bushigh(void) { pin.output(); pin = 1; }
andrewboyson 6:be97d38e0b01 35 static void busread(void) { busvalue = pin; }
andrewboyson 4:e076884ef8bd 36
andrewboyson 4:e076884ef8bd 37 //Exchange zone
andrewboyson 4:e076884ef8bd 38 //=============
andrewboyson 6:be97d38e0b01 39 #define STATE_IDLE 0
andrewboyson 6:be97d38e0b01 40 #define RESET_LOW 1
andrewboyson 6:be97d38e0b01 41 #define RESET_RELEASE 2
andrewboyson 6:be97d38e0b01 42 #define XCHG_WRITE 3
andrewboyson 6:be97d38e0b01 43 #define PULL_UP 4
andrewboyson 6:be97d38e0b01 44 #define XCHG_READ 5
andrewboyson 6:be97d38e0b01 45 #define SEARCH_WRITE 6
andrewboyson 6:be97d38e0b01 46 #define SEARCH_BIT 7
andrewboyson 6:be97d38e0b01 47 #define SEARCH_READ_BIT_TRUE 8
andrewboyson 6:be97d38e0b01 48 #define SEARCH_READ_BIT_COMP 9
andrewboyson 6:be97d38e0b01 49 #define SEARCH_WRITE_BIT 10
andrewboyson 6:be97d38e0b01 50 static int state = STATE_IDLE;
andrewboyson 6:be97d38e0b01 51
andrewboyson 6:be97d38e0b01 52 #define JOB_NONE 0
andrewboyson 6:be97d38e0b01 53 #define JOB_XCHG 1
andrewboyson 6:be97d38e0b01 54 #define JOB_SEARCH 2
andrewboyson 6:be97d38e0b01 55 static int job = JOB_NONE;
andrewboyson 4:e076884ef8bd 56
andrewboyson 4:e076884ef8bd 57 static int lensend = 0;
andrewboyson 4:e076884ef8bd 58 static int lenrecv = 0;
andrewboyson 4:e076884ef8bd 59 static char* psend = NULL;
andrewboyson 4:e076884ef8bd 60 static char* precv = NULL;
andrewboyson 4:e076884ef8bd 61 static int pullupms = 0;
andrewboyson 4:e076884ef8bd 62
andrewboyson 6:be97d38e0b01 63 static void initiateResetLow(int jobtype)
andrewboyson 6:be97d38e0b01 64 {
andrewboyson 6:be97d38e0b01 65 buslow();
andrewboyson 6:be97d38e0b01 66 timer.stop();
andrewboyson 6:be97d38e0b01 67 timer.reset();
andrewboyson 6:be97d38e0b01 68 timer.start();
andrewboyson 6:be97d38e0b01 69 state = RESET_LOW;
andrewboyson 6:be97d38e0b01 70 job = jobtype;
andrewboyson 6:be97d38e0b01 71 }
andrewboyson 6:be97d38e0b01 72 static void readPresenceAndAwaitResetRelease()
andrewboyson 6:be97d38e0b01 73 {
andrewboyson 6:be97d38e0b01 74 busfree();
andrewboyson 6:be97d38e0b01 75 wait_us(READ_PRESENCE_US);
andrewboyson 6:be97d38e0b01 76 busread();
andrewboyson 6:be97d38e0b01 77 timer.stop();
andrewboyson 6:be97d38e0b01 78 timer.reset();
andrewboyson 6:be97d38e0b01 79 timer.start();
andrewboyson 6:be97d38e0b01 80 state = RESET_RELEASE;
andrewboyson 6:be97d38e0b01 81 }
andrewboyson 6:be97d38e0b01 82 static void writeBit(int bit)
andrewboyson 6:be97d38e0b01 83 {
andrewboyson 6:be97d38e0b01 84 buslow();
andrewboyson 6:be97d38e0b01 85 wait_us(bit ? WRITE_1_BUS_LOW_US : WRITE_0_BUS_LOW_US);
andrewboyson 6:be97d38e0b01 86 busfree();
andrewboyson 6:be97d38e0b01 87 wait_us(bit ? WRITE_1_RELEASE_US : WRITE_0_RELEASE_US);
andrewboyson 6:be97d38e0b01 88 }
andrewboyson 6:be97d38e0b01 89 static void writeBitWithPullUp(int bit)
andrewboyson 6:be97d38e0b01 90 {
andrewboyson 6:be97d38e0b01 91 buslow();
andrewboyson 6:be97d38e0b01 92 wait_us(bit ? WRITE_1_BUS_LOW_US : WRITE_0_BUS_LOW_US);
andrewboyson 6:be97d38e0b01 93 bushigh();
andrewboyson 6:be97d38e0b01 94 timer.stop();
andrewboyson 6:be97d38e0b01 95 timer.reset();
andrewboyson 6:be97d38e0b01 96 timer.start();
andrewboyson 6:be97d38e0b01 97 state = PULL_UP;
andrewboyson 6:be97d38e0b01 98 }
andrewboyson 6:be97d38e0b01 99 static void readBit()
andrewboyson 6:be97d38e0b01 100 {
andrewboyson 6:be97d38e0b01 101 buslow();
andrewboyson 6:be97d38e0b01 102 wait_us(READ_BIT_BUS_LOW_US);
andrewboyson 6:be97d38e0b01 103 busfree();
andrewboyson 6:be97d38e0b01 104 wait_us(READ_BIT_US);
andrewboyson 6:be97d38e0b01 105 busread();
andrewboyson 6:be97d38e0b01 106 wait_us(READ_BIT_RELEASE_US);
andrewboyson 6:be97d38e0b01 107 }
andrewboyson 6:be97d38e0b01 108
andrewboyson 5:6226f3c566ef 109 static char crc;
andrewboyson 5:6226f3c566ef 110 static void resetCrc()
andrewboyson 5:6226f3c566ef 111 {
andrewboyson 5:6226f3c566ef 112 crc = 0;
andrewboyson 5:6226f3c566ef 113 }
andrewboyson 5:6226f3c566ef 114 static void addBitToCrc(int bit)
andrewboyson 5:6226f3c566ef 115 {
andrewboyson 6:be97d38e0b01 116 int feedback = !(crc & 0x80) != !bit; //Logical Exclusive Or of the msb of the shift register with the input
andrewboyson 6:be97d38e0b01 117 crc <<= 1; //Move the shift register one place to the left leaving a zero in the lsb and losing the msb
andrewboyson 6:be97d38e0b01 118 if (feedback) crc ^= 0x31; //Exclusive Or the shift register with polynomial X5 + X4 + 1
andrewboyson 5:6226f3c566ef 119 }
andrewboyson 5:6226f3c566ef 120
andrewboyson 4:e076884ef8bd 121 static void resetBitPosition(int* pByteIndex, char* pBitMask)
andrewboyson 4:e076884ef8bd 122 {
andrewboyson 4:e076884ef8bd 123 *pBitMask = 1;
andrewboyson 4:e076884ef8bd 124 *pByteIndex = 0;
andrewboyson 4:e076884ef8bd 125 }
andrewboyson 4:e076884ef8bd 126 static void incrementBitPosition(int* pByteIndex, char* pBitMask)
andrewboyson 4:e076884ef8bd 127 {
andrewboyson 4:e076884ef8bd 128 *pBitMask <<= 1;
andrewboyson 4:e076884ef8bd 129 if (!*pBitMask)
andrewboyson 4:e076884ef8bd 130 {
andrewboyson 4:e076884ef8bd 131 *pBitMask = 1;
andrewboyson 4:e076884ef8bd 132 *pByteIndex += 1;
andrewboyson 4:e076884ef8bd 133 }
andrewboyson 4:e076884ef8bd 134 }
andrewboyson 4:e076884ef8bd 135
andrewboyson 4:e076884ef8bd 136 int getBitAtPosition(int byteIndex, char bitMask)
andrewboyson 4:e076884ef8bd 137 {
andrewboyson 4:e076884ef8bd 138 return psend[byteIndex] & bitMask;
andrewboyson 4:e076884ef8bd 139 }
andrewboyson 4:e076884ef8bd 140 void setBitAtPosition(int byteIndex, char bitMask, int bit)
andrewboyson 4:e076884ef8bd 141 {
andrewboyson 6:be97d38e0b01 142 if ( bit) precv[byteIndex] |= bitMask;
andrewboyson 6:be97d38e0b01 143 else precv[byteIndex] &= ~bitMask;
andrewboyson 4:e076884ef8bd 144 }
andrewboyson 4:e076884ef8bd 145 int moreBitsToRead(int byteIndex)
andrewboyson 4:e076884ef8bd 146 {
andrewboyson 4:e076884ef8bd 147 return byteIndex < lenrecv;
andrewboyson 4:e076884ef8bd 148 }
andrewboyson 4:e076884ef8bd 149 int moreBitsToWrite(int byteIndex)
andrewboyson 4:e076884ef8bd 150 {
andrewboyson 4:e076884ef8bd 151 return byteIndex < lensend;
andrewboyson 4:e076884ef8bd 152 }
andrewboyson 6:be97d38e0b01 153
andrewboyson 6:be97d38e0b01 154 int result = ONE_WIRE_RESULT_OK;
andrewboyson 6:be97d38e0b01 155 int OneWireResult()
andrewboyson 6:be97d38e0b01 156 {
andrewboyson 6:be97d38e0b01 157 return result;
andrewboyson 6:be97d38e0b01 158 }
andrewboyson 4:e076884ef8bd 159 int OneWireInit()
andrewboyson 4:e076884ef8bd 160 {
andrewboyson 6:be97d38e0b01 161 busfree();
andrewboyson 6:be97d38e0b01 162 busytimer.stop();
andrewboyson 6:be97d38e0b01 163 busytimer.reset();
andrewboyson 6:be97d38e0b01 164 state = STATE_IDLE;
andrewboyson 6:be97d38e0b01 165 job = JOB_NONE;
andrewboyson 4:e076884ef8bd 166 return 0;
andrewboyson 4:e076884ef8bd 167 }
andrewboyson 4:e076884ef8bd 168 int OneWireBusy()
andrewboyson 4:e076884ef8bd 169 {
andrewboyson 6:be97d38e0b01 170 return state;
andrewboyson 4:e076884ef8bd 171 }
andrewboyson 4:e076884ef8bd 172 void OneWireExchange(int lenBytesToSend, int lenBytesToRecv, char *pBytesToSend, char *pBytesToRecv, int msToPullUp)
andrewboyson 4:e076884ef8bd 173 {
andrewboyson 4:e076884ef8bd 174 lensend = lenBytesToSend;
andrewboyson 4:e076884ef8bd 175 lenrecv = lenBytesToRecv;
andrewboyson 4:e076884ef8bd 176 psend = pBytesToSend;
andrewboyson 4:e076884ef8bd 177 precv = pBytesToRecv;
andrewboyson 4:e076884ef8bd 178 pullupms = msToPullUp;
andrewboyson 6:be97d38e0b01 179 initiateResetLow(JOB_XCHG);
andrewboyson 6:be97d38e0b01 180 }
andrewboyson 6:be97d38e0b01 181 static int* pallfound;
andrewboyson 6:be97d38e0b01 182 static char* prom;
andrewboyson 6:be97d38e0b01 183 static void setRomBit(int position, int bit)
andrewboyson 6:be97d38e0b01 184 {
andrewboyson 6:be97d38e0b01 185 int bitindex = position & 0x07;
andrewboyson 6:be97d38e0b01 186 int byteindex = position >> 3;
andrewboyson 6:be97d38e0b01 187 int bitmask = 1 << bitindex;
andrewboyson 6:be97d38e0b01 188 if (bit) *(prom + byteindex) |= bitmask;
andrewboyson 6:be97d38e0b01 189 else *(prom + byteindex) &= ~bitmask;
andrewboyson 6:be97d38e0b01 190 }
andrewboyson 6:be97d38e0b01 191 static int getRomBit(int position)
andrewboyson 6:be97d38e0b01 192 {
andrewboyson 6:be97d38e0b01 193 int bitindex = position & 0x07;
andrewboyson 6:be97d38e0b01 194 int byteindex = position >> 3;
andrewboyson 6:be97d38e0b01 195 int bitmask = 1 << bitindex;
andrewboyson 6:be97d38e0b01 196 return *(prom + byteindex) & bitmask;
andrewboyson 6:be97d38e0b01 197 }
andrewboyson 6:be97d38e0b01 198 static int thisFurthestForkLeftPosn;
andrewboyson 6:be97d38e0b01 199 static int lastFurthestForkLeftPosn;
andrewboyson 6:be97d38e0b01 200 static char searchCommand;
andrewboyson 6:be97d38e0b01 201 static int searchBitPosn;
andrewboyson 6:be97d38e0b01 202 static int searchBitTrue;
andrewboyson 6:be97d38e0b01 203 static int searchBitComp;
andrewboyson 6:be97d38e0b01 204 static int chooseDirectionToTake()
andrewboyson 6:be97d38e0b01 205 {
andrewboyson 6:be97d38e0b01 206 if ( searchBitTrue && searchBitComp) return -1; //No devices are participating in the search
andrewboyson 6:be97d38e0b01 207 if ( searchBitTrue && !searchBitComp) return 1; //Only devices with a one at this point are participating
andrewboyson 6:be97d38e0b01 208 if (!searchBitTrue && searchBitComp) return 0; //Only devices with a zero at this point are participating
andrewboyson 6:be97d38e0b01 209 //Both bits are zero so devices with both 0s and 1s at this point are still participating
andrewboyson 6:be97d38e0b01 210
andrewboyson 6:be97d38e0b01 211 //If we have not yet reached the furthest away point we forked left (0) last time then just do whatever we did last time
andrewboyson 6:be97d38e0b01 212 if (searchBitPosn < lastFurthestForkLeftPosn) return getRomBit(searchBitPosn);
andrewboyson 6:be97d38e0b01 213
andrewboyson 6:be97d38e0b01 214 //If we are at the furthest away point that we forked left (0) last time then this time fork right (1)
andrewboyson 6:be97d38e0b01 215 if (searchBitPosn == lastFurthestForkLeftPosn) return 1;
andrewboyson 6:be97d38e0b01 216
andrewboyson 6:be97d38e0b01 217 //We are at a new fork point further than we have been before so fork left (0) and record that we did so.
andrewboyson 6:be97d38e0b01 218 thisFurthestForkLeftPosn = searchBitPosn;
andrewboyson 6:be97d38e0b01 219 return 0;
andrewboyson 6:be97d38e0b01 220 }
andrewboyson 6:be97d38e0b01 221 void OneWireSearch(char command, char* pDeviceRom, int* pAllDevicesFound) //Specify the buffer to receive the rom for the first search and NULL thereafter.
andrewboyson 6:be97d38e0b01 222 {
andrewboyson 6:be97d38e0b01 223 if (pDeviceRom)
andrewboyson 6:be97d38e0b01 224 {
andrewboyson 6:be97d38e0b01 225 pallfound = pAllDevicesFound;
andrewboyson 6:be97d38e0b01 226 *pallfound = false;
andrewboyson 6:be97d38e0b01 227 lastFurthestForkLeftPosn = -1;
andrewboyson 6:be97d38e0b01 228 prom = pDeviceRom;
andrewboyson 6:be97d38e0b01 229 for (int i = 0; i < 8; i++) *(prom + i) = 0;
andrewboyson 6:be97d38e0b01 230 }
andrewboyson 6:be97d38e0b01 231 thisFurthestForkLeftPosn = -1;
andrewboyson 6:be97d38e0b01 232 lensend = 1;
andrewboyson 6:be97d38e0b01 233 lenrecv = 0;
andrewboyson 6:be97d38e0b01 234 searchCommand = command;
andrewboyson 6:be97d38e0b01 235 psend = &searchCommand;
andrewboyson 6:be97d38e0b01 236 precv = NULL;
andrewboyson 6:be97d38e0b01 237 pullupms = 0;
andrewboyson 6:be97d38e0b01 238 initiateResetLow(JOB_SEARCH);
andrewboyson 4:e076884ef8bd 239 }
andrewboyson 5:6226f3c566ef 240 char OneWireCrc()
andrewboyson 5:6226f3c566ef 241 {
andrewboyson 5:6226f3c566ef 242 return crc;
andrewboyson 5:6226f3c566ef 243 }
andrewboyson 4:e076884ef8bd 244 int OneWireMain()
andrewboyson 4:e076884ef8bd 245 {
andrewboyson 4:e076884ef8bd 246 static int byteindex;
andrewboyson 4:e076884ef8bd 247 static char bitmask;
andrewboyson 4:e076884ef8bd 248
andrewboyson 6:be97d38e0b01 249 if (state)
andrewboyson 4:e076884ef8bd 250 {
andrewboyson 6:be97d38e0b01 251 busytimer.start();
andrewboyson 6:be97d38e0b01 252 if (busytimer.read_ms() > BUS_TIMEOUT_MS)
andrewboyson 4:e076884ef8bd 253 {
andrewboyson 4:e076884ef8bd 254 LogCrLf("1-wire bus timed out so protocol has been reset to idle.");
andrewboyson 4:e076884ef8bd 255 OneWireInit();
andrewboyson 6:be97d38e0b01 256 result = ONE_WIRE_RESULT_TIMED_OUT;
andrewboyson 6:be97d38e0b01 257 return 0;
andrewboyson 4:e076884ef8bd 258 }
andrewboyson 4:e076884ef8bd 259 }
andrewboyson 4:e076884ef8bd 260 else
andrewboyson 4:e076884ef8bd 261 {
andrewboyson 6:be97d38e0b01 262 busytimer.stop();
andrewboyson 6:be97d38e0b01 263 busytimer.reset();
andrewboyson 4:e076884ef8bd 264 }
andrewboyson 4:e076884ef8bd 265
andrewboyson 6:be97d38e0b01 266 switch(state)
andrewboyson 4:e076884ef8bd 267 {
andrewboyson 6:be97d38e0b01 268 case STATE_IDLE:
andrewboyson 4:e076884ef8bd 269 break;
andrewboyson 6:be97d38e0b01 270 case RESET_LOW:
andrewboyson 6:be97d38e0b01 271 if (timer.read_us() > RESET_BUS_LOW_US) readPresenceAndAwaitResetRelease();
andrewboyson 6:be97d38e0b01 272 break;
andrewboyson 6:be97d38e0b01 273 case RESET_RELEASE:
andrewboyson 6:be97d38e0b01 274 if (timer.read_us() > RESET_RELEASE_US)
andrewboyson 4:e076884ef8bd 275 {
andrewboyson 6:be97d38e0b01 276 busfree();
andrewboyson 6:be97d38e0b01 277 timer.stop();
andrewboyson 6:be97d38e0b01 278 timer.reset();
andrewboyson 6:be97d38e0b01 279 if (busvalue)
andrewboyson 6:be97d38e0b01 280 {
andrewboyson 6:be97d38e0b01 281 LogCrLf("No 1-wire device presence detected on the bus");
andrewboyson 6:be97d38e0b01 282 result = ONE_WIRE_RESULT_NO_DEVICE_PRESENT;
andrewboyson 6:be97d38e0b01 283 state = STATE_IDLE;
andrewboyson 6:be97d38e0b01 284 }
andrewboyson 6:be97d38e0b01 285 else
andrewboyson 6:be97d38e0b01 286 {
andrewboyson 6:be97d38e0b01 287 resetBitPosition(&byteindex, &bitmask);
andrewboyson 6:be97d38e0b01 288 switch (job)
andrewboyson 6:be97d38e0b01 289 {
andrewboyson 6:be97d38e0b01 290 case JOB_XCHG: state = XCHG_WRITE; break;
andrewboyson 6:be97d38e0b01 291 case JOB_SEARCH: state = SEARCH_WRITE; break;
andrewboyson 6:be97d38e0b01 292 default:
andrewboyson 6:be97d38e0b01 293 LogF("Unknown job in RESET_RELEASE %d\r\n", job);
andrewboyson 6:be97d38e0b01 294 return -1;
andrewboyson 6:be97d38e0b01 295 }
andrewboyson 6:be97d38e0b01 296 }
andrewboyson 4:e076884ef8bd 297 }
andrewboyson 4:e076884ef8bd 298 break;
andrewboyson 6:be97d38e0b01 299
andrewboyson 4:e076884ef8bd 300 case XCHG_WRITE:
andrewboyson 4:e076884ef8bd 301 if (moreBitsToWrite(byteindex))
andrewboyson 4:e076884ef8bd 302 {
andrewboyson 4:e076884ef8bd 303 int bit = getBitAtPosition(byteindex, bitmask);
andrewboyson 4:e076884ef8bd 304 incrementBitPosition(&byteindex, &bitmask);
andrewboyson 6:be97d38e0b01 305 if (moreBitsToWrite(byteindex)) writeBit(bit);
andrewboyson 6:be97d38e0b01 306 else writeBitWithPullUp(bit);
andrewboyson 4:e076884ef8bd 307 }
andrewboyson 4:e076884ef8bd 308 else
andrewboyson 4:e076884ef8bd 309 {
andrewboyson 4:e076884ef8bd 310 resetBitPosition(&byteindex, &bitmask);
andrewboyson 4:e076884ef8bd 311 if (moreBitsToRead(byteindex))
andrewboyson 4:e076884ef8bd 312 {
andrewboyson 5:6226f3c566ef 313 resetCrc();
andrewboyson 6:be97d38e0b01 314 readBit();
andrewboyson 6:be97d38e0b01 315 state = XCHG_READ;
andrewboyson 4:e076884ef8bd 316
andrewboyson 4:e076884ef8bd 317 }
andrewboyson 4:e076884ef8bd 318 else
andrewboyson 4:e076884ef8bd 319 {
andrewboyson 6:be97d38e0b01 320 result = ONE_WIRE_RESULT_OK;
andrewboyson 6:be97d38e0b01 321 state = STATE_IDLE;
andrewboyson 4:e076884ef8bd 322 }
andrewboyson 4:e076884ef8bd 323 }
andrewboyson 4:e076884ef8bd 324 break;
andrewboyson 6:be97d38e0b01 325 case PULL_UP:
andrewboyson 6:be97d38e0b01 326 if (timer.read_ms() > pullupms)
andrewboyson 6:be97d38e0b01 327 {
andrewboyson 6:be97d38e0b01 328 busfree();
andrewboyson 6:be97d38e0b01 329 switch (job)
andrewboyson 6:be97d38e0b01 330 {
andrewboyson 6:be97d38e0b01 331 case JOB_XCHG: state = XCHG_WRITE; break;
andrewboyson 6:be97d38e0b01 332 default:
andrewboyson 6:be97d38e0b01 333 LogF("Unknown job in PULL_UP %d\r\n", job);
andrewboyson 6:be97d38e0b01 334 return -1;
andrewboyson 6:be97d38e0b01 335 }
andrewboyson 6:be97d38e0b01 336 }
andrewboyson 6:be97d38e0b01 337 break;
andrewboyson 4:e076884ef8bd 338 case XCHG_READ:
andrewboyson 5:6226f3c566ef 339 addBitToCrc(busvalue);
andrewboyson 4:e076884ef8bd 340 setBitAtPosition(byteindex, bitmask, busvalue);
andrewboyson 4:e076884ef8bd 341 incrementBitPosition(&byteindex, &bitmask);
andrewboyson 4:e076884ef8bd 342 if (moreBitsToRead(byteindex))
andrewboyson 4:e076884ef8bd 343 {
andrewboyson 6:be97d38e0b01 344 readBit();
andrewboyson 6:be97d38e0b01 345 }
andrewboyson 6:be97d38e0b01 346 else
andrewboyson 6:be97d38e0b01 347 {
andrewboyson 6:be97d38e0b01 348 state = STATE_IDLE;
andrewboyson 6:be97d38e0b01 349 result = crc ? ONE_WIRE_RESULT_CRC_ERROR : ONE_WIRE_RESULT_OK;
andrewboyson 6:be97d38e0b01 350 }
andrewboyson 6:be97d38e0b01 351 break;
andrewboyson 6:be97d38e0b01 352
andrewboyson 6:be97d38e0b01 353 case SEARCH_WRITE:
andrewboyson 6:be97d38e0b01 354 if (moreBitsToWrite(byteindex))
andrewboyson 6:be97d38e0b01 355 {
andrewboyson 6:be97d38e0b01 356 int bit = getBitAtPosition(byteindex, bitmask);
andrewboyson 6:be97d38e0b01 357 incrementBitPosition(&byteindex, &bitmask);
andrewboyson 6:be97d38e0b01 358 writeBit(bit);
andrewboyson 4:e076884ef8bd 359 }
andrewboyson 4:e076884ef8bd 360 else
andrewboyson 4:e076884ef8bd 361 {
andrewboyson 6:be97d38e0b01 362 searchBitPosn = 0;
andrewboyson 6:be97d38e0b01 363 state = SEARCH_BIT;
andrewboyson 6:be97d38e0b01 364 }
andrewboyson 6:be97d38e0b01 365 break;
andrewboyson 6:be97d38e0b01 366 case SEARCH_BIT:
andrewboyson 6:be97d38e0b01 367 readBit();
andrewboyson 6:be97d38e0b01 368 state = SEARCH_READ_BIT_TRUE;
andrewboyson 6:be97d38e0b01 369 break;
andrewboyson 6:be97d38e0b01 370 case SEARCH_READ_BIT_TRUE:
andrewboyson 6:be97d38e0b01 371 searchBitTrue = busvalue;
andrewboyson 6:be97d38e0b01 372 readBit();
andrewboyson 6:be97d38e0b01 373 state = SEARCH_READ_BIT_COMP;
andrewboyson 6:be97d38e0b01 374 break;
andrewboyson 6:be97d38e0b01 375 case SEARCH_READ_BIT_COMP:
andrewboyson 6:be97d38e0b01 376 searchBitComp = busvalue;
andrewboyson 6:be97d38e0b01 377 state = SEARCH_WRITE_BIT;
andrewboyson 6:be97d38e0b01 378 break;
andrewboyson 6:be97d38e0b01 379 case SEARCH_WRITE_BIT:
andrewboyson 7:024ace6d943c 380 if (DEBUG) LogF("%d%d - ", searchBitTrue, searchBitComp);
andrewboyson 6:be97d38e0b01 381 int direction;
andrewboyson 6:be97d38e0b01 382 direction = chooseDirectionToTake();
andrewboyson 6:be97d38e0b01 383 if (direction == -1)
andrewboyson 6:be97d38e0b01 384 {
andrewboyson 6:be97d38e0b01 385 LogCrLf("No devices have responded");
andrewboyson 6:be97d38e0b01 386 result = ONE_WIRE_RESULT_NO_DEVICE_PARTICIPATING;
andrewboyson 6:be97d38e0b01 387 state = STATE_IDLE;
andrewboyson 6:be97d38e0b01 388 }
andrewboyson 6:be97d38e0b01 389 else
andrewboyson 6:be97d38e0b01 390 {
andrewboyson 7:024ace6d943c 391 if (DEBUG) LogF(" %d -> %d\r\n", direction, searchBitPosn);
andrewboyson 6:be97d38e0b01 392 setRomBit(searchBitPosn, direction);
andrewboyson 6:be97d38e0b01 393 writeBit(direction);
andrewboyson 6:be97d38e0b01 394 searchBitPosn++;
andrewboyson 6:be97d38e0b01 395 if (searchBitPosn < 64)
andrewboyson 6:be97d38e0b01 396 {
andrewboyson 6:be97d38e0b01 397 state = SEARCH_BIT;
andrewboyson 6:be97d38e0b01 398 }
andrewboyson 6:be97d38e0b01 399 else
andrewboyson 6:be97d38e0b01 400 {
andrewboyson 6:be97d38e0b01 401 if (thisFurthestForkLeftPosn == -1) *pallfound = true;
andrewboyson 6:be97d38e0b01 402 lastFurthestForkLeftPosn = thisFurthestForkLeftPosn;
andrewboyson 6:be97d38e0b01 403 result = ONE_WIRE_RESULT_OK;
andrewboyson 6:be97d38e0b01 404 state = STATE_IDLE;
andrewboyson 6:be97d38e0b01 405 }
andrewboyson 4:e076884ef8bd 406 }
andrewboyson 4:e076884ef8bd 407 break;
andrewboyson 4:e076884ef8bd 408 default:
andrewboyson 6:be97d38e0b01 409 LogF("Unknown state %d\r\n", state);
andrewboyson 4:e076884ef8bd 410 return -1;
andrewboyson 4:e076884ef8bd 411 }
andrewboyson 4:e076884ef8bd 412 return 0;
andrewboyson 4:e076884ef8bd 413 }