Green Team / DS1820

Greenhouse project

Dependencies:   LinkedList

Dependents:   greenhouse_proj

Fork of DS1820 by Erik -

DS1820.cpp@16:b408decfb53d, 2017-11-24 (annotated)

Committer:
cricbis
Date:
Fri Nov 24 15:50:17 2017 +0000
Revision:
16:b408decfb53d
Parent:
14:c591209285e9 
vf

Who changed what in which revision?

UserRevisionLine numberNew contents of line
pairmand 3:8f2b7f4940b5 1 #include "DS1820.h"
Sissors 5:2cd4928e8147 2
Sissors 14:c591209285e9 3 #ifdef TARGET_STM
Sissors 14:c591209285e9 4 //STM targets use opendrain mode since their GPIO code is too bad to be used like the others
Sissors 14:c591209285e9 5 #define ONEWIRE_INPUT(pin) pin->write(1)
Sissors 14:c591209285e9 6 #define ONEWIRE_OUTPUT(pin)
Sissors 14:c591209285e9 7 #define ONEWIRE_INIT(pin) pin->output(); pin->mode(OpenDrain)
Sissors 14:c591209285e9 8
Sissors 14:c591209285e9 9 // TEMP, remove once STM fixed their stuff
Sissors 14:c591209285e9 10 // Enable GPIO clock and return GPIO base address
Sissors 14:c591209285e9 11 static uint32_t Set_GPIO_Clock(uint32_t port_idx) {
Sissors 14:c591209285e9 12 uint32_t gpio_add = 0;
Sissors 14:c591209285e9 13 switch (port_idx) {
Sissors 14:c591209285e9 14 case PortA:
Sissors 14:c591209285e9 15 gpio_add = GPIOA_BASE;
Sissors 14:c591209285e9 16 __GPIOA_CLK_ENABLE();
Sissors 14:c591209285e9 17 break;
Sissors 14:c591209285e9 18 case PortB:
Sissors 14:c591209285e9 19 gpio_add = GPIOB_BASE;
Sissors 14:c591209285e9 20 __GPIOB_CLK_ENABLE();
Sissors 14:c591209285e9 21 break;
Sissors 14:c591209285e9 22 #if defined(GPIOC_BASE)
Sissors 14:c591209285e9 23 case PortC:
Sissors 14:c591209285e9 24 gpio_add = GPIOC_BASE;
Sissors 14:c591209285e9 25 __GPIOC_CLK_ENABLE();
Sissors 14:c591209285e9 26 break;
Sissors 14:c591209285e9 27 #endif
Sissors 14:c591209285e9 28 #if defined(GPIOD_BASE)
Sissors 14:c591209285e9 29 case PortD:
Sissors 14:c591209285e9 30 gpio_add = GPIOD_BASE;
Sissors 14:c591209285e9 31 __GPIOD_CLK_ENABLE();
Sissors 14:c591209285e9 32 break;
Sissors 14:c591209285e9 33 #endif
Sissors 14:c591209285e9 34 #if defined(GPIOF_BASE)
Sissors 14:c591209285e9 35 case PortF:
Sissors 14:c591209285e9 36 gpio_add = GPIOF_BASE;
Sissors 14:c591209285e9 37 __GPIOF_CLK_ENABLE();
Sissors 14:c591209285e9 38 break;
Sissors 14:c591209285e9 39 #endif
Sissors 14:c591209285e9 40 default:
Sissors 14:c591209285e9 41 error("Pinmap error: wrong port number.");
Sissors 14:c591209285e9 42 break;
Sissors 14:c591209285e9 43 }
Sissors 14:c591209285e9 44 return gpio_add;
Sissors 14:c591209285e9 45 }
Sissors 14:c591209285e9 46
Sissors 14:c591209285e9 47
Sissors 14:c591209285e9 48 #else
Sissors 14:c591209285e9 49 #define ONEWIRE_INPUT(pin) pin->input()
Sissors 14:c591209285e9 50 #define ONEWIRE_OUTPUT(pin) pin->output()
Sissors 14:c591209285e9 51 #define ONEWIRE_INIT(pin)
Sissors 14:c591209285e9 52 #endif
Sissors 14:c591209285e9 53
Sissors 5:2cd4928e8147 54 LinkedList<node> DS1820::probes;
pairmand 3:8f2b7f4940b5 55
pairmand 3:8f2b7f4940b5 56
Sissors 5:2cd4928e8147 57 DS1820::DS1820 (PinName data_pin, PinName power_pin, bool power_polarity) : _datapin(data_pin), _parasitepin(power_pin) {
pairmand 3:8f2b7f4940b5 58 int byte_counter;
Sissors 5:2cd4928e8147 59 _power_polarity = power_polarity;
florian 9:3821ca0b7f14 60
florian 9:3821ca0b7f14 61 _power_mosfet = power_pin != NC;
Sissors 5:2cd4928e8147 62
pairmand 3:8f2b7f4940b5 63 for(byte_counter=0;byte_counter<9;byte_counter++)
pairmand 3:8f2b7f4940b5 64 RAM[byte_counter] = 0x00;
Sissors 5:2cd4928e8147 65
Sissors 14:c591209285e9 66 ONEWIRE_INIT((&_datapin));
Sissors 14:c591209285e9 67 // Temp code since the above doesn't actually do anything in mbed revisions up to 133
Sissors 14:c591209285e9 68 #ifdef TARGET_STM
Sissors 14:c591209285e9 69
Sissors 14:c591209285e9 70 uint32_t port_index = STM_PORT(data_pin);
Sissors 14:c591209285e9 71 uint32_t pin_index = STM_PIN(data_pin);
Sissors 14:c591209285e9 72
Sissors 14:c591209285e9 73 // Enable GPIO clock
Sissors 14:c591209285e9 74 uint32_t gpio_add = Set_GPIO_Clock(port_index);
Sissors 14:c591209285e9 75 GPIO_TypeDef *gpio = (GPIO_TypeDef *)gpio_add;
Sissors 14:c591209285e9 76
Sissors 14:c591209285e9 77 gpio->OTYPER |= (uint32_t)(1 << pin_index);
Sissors 14:c591209285e9 78 #endif
Sissors 14:c591209285e9 79
Sissors 5:2cd4928e8147 80 if (!unassignedProbe(&_datapin, _ROM))
Sissors 5:2cd4928e8147 81 error("No unassigned DS1820 found!\n");
Sissors 5:2cd4928e8147 82 else {
Sissors 5:2cd4928e8147 83 _datapin.input();
Sissors 5:2cd4928e8147 84 probes.append(this);
Sissors 5:2cd4928e8147 85 _parasite_power = !read_power_supply();
Sissors 5:2cd4928e8147 86 }
pairmand 3:8f2b7f4940b5 87 }
Sissors 5:2cd4928e8147 88
cricbis 16:b408decfb53d 89 DS1820::~DS1820 (void) { ///////////////////////////////////
cricbis 16:b408decfb53d 90 node *tmp; ///////////////////////////////////
cricbis 16:b408decfb53d 91 for(int i=1; i<=probes.length(); i++) ///////////////////////////////////
cricbis 16:b408decfb53d 92 { ///////////////////////////////////
cricbis 16:b408decfb53d 93 tmp = probes.pop(i); ///////////////////////////////////
cricbis 16:b408decfb53d 94 if (tmp->data == this) ///////////////////////////////////
cricbis 16:b408decfb53d 95 probes.remove(i); ///////////////////////////////////
Sissors 5:2cd4928e8147 96 }
pairmand 3:8f2b7f4940b5 97 }
Sissors 5:2cd4928e8147 98
pairmand 3:8f2b7f4940b5 99
Sissors 5:2cd4928e8147 100 bool DS1820::onewire_reset(DigitalInOut *pin) {
pairmand 3:8f2b7f4940b5 101 // This will return false if no devices are present on the data bus
pairmand 3:8f2b7f4940b5 102 bool presence=false;
Sissors 14:c591209285e9 103 ONEWIRE_OUTPUT(pin);
Sissors 5:2cd4928e8147 104 pin->write(0); // bring low for 500 us
pairmand 3:8f2b7f4940b5 105 wait_us(500);
Sissors 14:c591209285e9 106 ONEWIRE_INPUT(pin); // let the data line float high
pairmand 3:8f2b7f4940b5 107 wait_us(90); // wait 90us
Sissors 5:2cd4928e8147 108 if (pin->read()==0) // see if any devices are pulling the data line low
pairmand 3:8f2b7f4940b5 109 presence=true;
pairmand 3:8f2b7f4940b5 110 wait_us(410);
pairmand 3:8f2b7f4940b5 111 return presence;
pairmand 3:8f2b7f4940b5 112 }
pairmand 3:8f2b7f4940b5 113
Sissors 5:2cd4928e8147 114 void DS1820::onewire_bit_out (DigitalInOut *pin, bool bit_data) {
Sissors 14:c591209285e9 115 ONEWIRE_OUTPUT(pin);
Sissors 5:2cd4928e8147 116 pin->write(0);
pairmand 3:8f2b7f4940b5 117 wait_us(3); // DXP modified from 5
pairmand 3:8f2b7f4940b5 118 if (bit_data) {
Sissors 8:d87e11e8d012 119 pin->write(1); // bring data line high
pairmand 3:8f2b7f4940b5 120 wait_us(55);
pairmand 3:8f2b7f4940b5 121 } else {
pairmand 3:8f2b7f4940b5 122 wait_us(55); // keep data line low
Sissors 8:d87e11e8d012 123 pin->write(1);
pairmand 3:8f2b7f4940b5 124 wait_us(10); // DXP added to allow bus to float high before next bit_out
pairmand 3:8f2b7f4940b5 125 }
pairmand 3:8f2b7f4940b5 126 }
pairmand 3:8f2b7f4940b5 127
pairmand 3:8f2b7f4940b5 128 void DS1820::onewire_byte_out(char data) { // output data character (least sig bit first).
pairmand 3:8f2b7f4940b5 129 int n;
pairmand 3:8f2b7f4940b5 130 for (n=0; n<8; n++) {
Sissors 5:2cd4928e8147 131 onewire_bit_out(&this->_datapin, data & 0x01);
pairmand 3:8f2b7f4940b5 132 data = data >> 1; // now the next bit is in the least sig bit position.
pairmand 3:8f2b7f4940b5 133 }
pairmand 3:8f2b7f4940b5 134 }
pairmand 3:8f2b7f4940b5 135
Sissors 5:2cd4928e8147 136 bool DS1820::onewire_bit_in(DigitalInOut *pin) {
pairmand 3:8f2b7f4940b5 137 bool answer;
Sissors 14:c591209285e9 138 ONEWIRE_OUTPUT(pin);
Sissors 5:2cd4928e8147 139 pin->write(0);
pairmand 3:8f2b7f4940b5 140 wait_us(3); // DXP modofied from 5
Sissors 14:c591209285e9 141 ONEWIRE_INPUT(pin);
pairmand 3:8f2b7f4940b5 142 wait_us(10); // DXP modified from 5
Sissors 5:2cd4928e8147 143 answer = pin->read();
pairmand 3:8f2b7f4940b5 144 wait_us(45); // DXP modified from 50
pairmand 3:8f2b7f4940b5 145 return answer;
pairmand 3:8f2b7f4940b5 146 }
pairmand 3:8f2b7f4940b5 147
pairmand 3:8f2b7f4940b5 148 char DS1820::onewire_byte_in() { // read byte, least sig byte first
pairmand 3:8f2b7f4940b5 149 char answer = 0x00;
pairmand 3:8f2b7f4940b5 150 int i;
pairmand 3:8f2b7f4940b5 151 for (i=0; i<8; i++) {
pairmand 3:8f2b7f4940b5 152 answer = answer >> 1; // shift over to make room for the next bit
Sissors 5:2cd4928e8147 153 if (onewire_bit_in(&this->_datapin))
pairmand 3:8f2b7f4940b5 154 answer = answer | 0x80; // if the data port is high, make this bit a 1
pairmand 3:8f2b7f4940b5 155 }
pairmand 3:8f2b7f4940b5 156 return answer;
pairmand 3:8f2b7f4940b5 157 }
Sissors 5:2cd4928e8147 158
Sissors 5:2cd4928e8147 159 bool DS1820::unassignedProbe(PinName pin) {
Sissors 5:2cd4928e8147 160 DigitalInOut _pin(pin);
Sissors 14:c591209285e9 161 ONEWIRE_INIT((&_pin));
Sissors 14:c591209285e9 162 // Temp code since the above doesn't actually do anything in mbed revisions up to 133
Sissors 14:c591209285e9 163 #ifdef TARGET_STM
Sissors 14:c591209285e9 164
Sissors 14:c591209285e9 165 uint32_t port_index = STM_PORT(pin);
Sissors 14:c591209285e9 166 uint32_t pin_index = STM_PIN(pin);
Sissors 14:c591209285e9 167
Sissors 14:c591209285e9 168 // Enable GPIO clock
Sissors 14:c591209285e9 169 uint32_t gpio_add = Set_GPIO_Clock(port_index);
Sissors 14:c591209285e9 170 GPIO_TypeDef *gpio = (GPIO_TypeDef *)gpio_add;
Sissors 14:c591209285e9 171
Sissors 14:c591209285e9 172 gpio->OTYPER |= (uint32_t)(1 << pin_index);
Sissors 14:c591209285e9 173 #endif
Sissors 5:2cd4928e8147 174 char ROM_address[8];
Sissors 5:2cd4928e8147 175 return search_ROM_routine(&_pin, 0xF0, ROM_address);
pairmand 3:8f2b7f4940b5 176 }
pairmand 3:8f2b7f4940b5 177
Sissors 5:2cd4928e8147 178 bool DS1820::unassignedProbe(DigitalInOut *pin, char *ROM_address) {
Sissors 5:2cd4928e8147 179 return search_ROM_routine(pin, 0xF0, ROM_address);
pairmand 3:8f2b7f4940b5 180 }
pairmand 3:8f2b7f4940b5 181
Sissors 5:2cd4928e8147 182 bool DS1820::search_ROM_routine(DigitalInOut *pin, char command, char *ROM_address) {
Sissors 5:2cd4928e8147 183 bool DS1820_done_flag = false;
Sissors 5:2cd4928e8147 184 int DS1820_last_descrepancy = 0;
Sissors 5:2cd4928e8147 185 char DS1820_search_ROM[8] = {0, 0, 0, 0, 0, 0, 0, 0};
Sissors 5:2cd4928e8147 186
pairmand 3:8f2b7f4940b5 187 int descrepancy_marker, ROM_bit_index;
pairmand 3:8f2b7f4940b5 188 bool return_value, Bit_A, Bit_B;
pairmand 3:8f2b7f4940b5 189 char byte_counter, bit_mask;
pairmand 3:8f2b7f4940b5 190
pairmand 3:8f2b7f4940b5 191 return_value=false;
Sissors 5:2cd4928e8147 192 while (!DS1820_done_flag) {
Sissors 5:2cd4928e8147 193 if (!onewire_reset(pin)) {
Sissors 5:2cd4928e8147 194 return false;
pairmand 3:8f2b7f4940b5 195 } else {
pairmand 3:8f2b7f4940b5 196 ROM_bit_index=1;
pairmand 3:8f2b7f4940b5 197 descrepancy_marker=0;
Sissors 12:196e9e54b033 198 char command_shift = command;
Sissors 5:2cd4928e8147 199 for (int n=0; n<8; n++) { // Search ROM command or Search Alarm command
Sissors 12:196e9e54b033 200 onewire_bit_out(pin, command_shift & 0x01);
Sissors 12:196e9e54b033 201 command_shift = command_shift >> 1; // now the next bit is in the least sig bit position.
Sissors 5:2cd4928e8147 202 }
pairmand 3:8f2b7f4940b5 203 byte_counter = 0;
pairmand 3:8f2b7f4940b5 204 bit_mask = 0x01;
pairmand 3:8f2b7f4940b5 205 while (ROM_bit_index<=64) {
Sissors 5:2cd4928e8147 206 Bit_A = onewire_bit_in(pin);
Sissors 5:2cd4928e8147 207 Bit_B = onewire_bit_in(pin);
pairmand 3:8f2b7f4940b5 208 if (Bit_A & Bit_B) {
pairmand 3:8f2b7f4940b5 209 descrepancy_marker = 0; // data read error, this should never happen
pairmand 3:8f2b7f4940b5 210 ROM_bit_index = 0xFF;
pairmand 3:8f2b7f4940b5 211 } else {
pairmand 3:8f2b7f4940b5 212 if (Bit_A | Bit_B) {
pairmand 3:8f2b7f4940b5 213 // Set ROM bit to Bit_A
pairmand 3:8f2b7f4940b5 214 if (Bit_A) {
pairmand 3:8f2b7f4940b5 215 DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] | bit_mask; // Set ROM bit to one
pairmand 3:8f2b7f4940b5 216 } else {
pairmand 3:8f2b7f4940b5 217 DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] & ~bit_mask; // Set ROM bit to zero
pairmand 3:8f2b7f4940b5 218 }
pairmand 3:8f2b7f4940b5 219 } else {
pairmand 3:8f2b7f4940b5 220 // both bits A and B are low, so there are two or more devices present
pairmand 3:8f2b7f4940b5 221 if ( ROM_bit_index == DS1820_last_descrepancy ) {
pairmand 3:8f2b7f4940b5 222 DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] | bit_mask; // Set ROM bit to one
pairmand 3:8f2b7f4940b5 223 } else {
pairmand 3:8f2b7f4940b5 224 if ( ROM_bit_index > DS1820_last_descrepancy ) {
pairmand 3:8f2b7f4940b5 225 DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] & ~bit_mask; // Set ROM bit to zero
pairmand 3:8f2b7f4940b5 226 descrepancy_marker = ROM_bit_index;
pairmand 3:8f2b7f4940b5 227 } else {
pairmand 3:8f2b7f4940b5 228 if (( DS1820_search_ROM[byte_counter] & bit_mask) == 0x00 )
pairmand 3:8f2b7f4940b5 229 descrepancy_marker = ROM_bit_index;
pairmand 3:8f2b7f4940b5 230 }
pairmand 3:8f2b7f4940b5 231 }
pairmand 3:8f2b7f4940b5 232 }
Sissors 5:2cd4928e8147 233 onewire_bit_out (pin, DS1820_search_ROM[byte_counter] & bit_mask);
pairmand 3:8f2b7f4940b5 234 ROM_bit_index++;
pairmand 3:8f2b7f4940b5 235 if (bit_mask & 0x80) {
pairmand 3:8f2b7f4940b5 236 byte_counter++;
pairmand 3:8f2b7f4940b5 237 bit_mask = 0x01;
pairmand 3:8f2b7f4940b5 238 } else {
pairmand 3:8f2b7f4940b5 239 bit_mask = bit_mask << 1;
pairmand 3:8f2b7f4940b5 240 }
pairmand 3:8f2b7f4940b5 241 }
pairmand 3:8f2b7f4940b5 242 }
pairmand 3:8f2b7f4940b5 243 DS1820_last_descrepancy = descrepancy_marker;
pairmand 3:8f2b7f4940b5 244 if (ROM_bit_index != 0xFF) {
Sissors 5:2cd4928e8147 245 int i = 1;
Sissors 5:2cd4928e8147 246 node *list_container;
Sissors 5:2cd4928e8147 247 while(1) {
Sissors 5:2cd4928e8147 248 list_container = probes.pop(i);
Sissors 5:2cd4928e8147 249 if (list_container == NULL) { //End of list, or empty list
Sissors 5:2cd4928e8147 250 if (ROM_checksum_error(DS1820_search_ROM)) { // Check the CRC
Sissors 5:2cd4928e8147 251 return false;
Sissors 5:2cd4928e8147 252 }
Sissors 5:2cd4928e8147 253 for(byte_counter=0;byte_counter<8;byte_counter++)
Sissors 5:2cd4928e8147 254 ROM_address[byte_counter] = DS1820_search_ROM[byte_counter];
Sissors 5:2cd4928e8147 255 return true;
Sissors 5:2cd4928e8147 256 } else { //Otherwise, check if ROM is already known
Sissors 5:2cd4928e8147 257 bool equal = true;
Sissors 5:2cd4928e8147 258 DS1820 *pointer = (DS1820*) list_container->data;
Sissors 5:2cd4928e8147 259 char *ROM_compare = pointer->_ROM;
Sissors 5:2cd4928e8147 260
Sissors 5:2cd4928e8147 261 for(byte_counter=0;byte_counter<8;byte_counter++) {
Sissors 5:2cd4928e8147 262 if ( ROM_compare[byte_counter] != DS1820_search_ROM[byte_counter])
Sissors 5:2cd4928e8147 263 equal = false;
Sissors 5:2cd4928e8147 264 }
Sissors 5:2cd4928e8147 265 if (equal)
Sissors 5:2cd4928e8147 266 break;
Sissors 5:2cd4928e8147 267 else
Sissors 5:2cd4928e8147 268 i++;
Sissors 5:2cd4928e8147 269 }
Sissors 5:2cd4928e8147 270 }
pairmand 3:8f2b7f4940b5 271 }
pairmand 3:8f2b7f4940b5 272 }
pairmand 3:8f2b7f4940b5 273 if (DS1820_last_descrepancy == 0)
pairmand 3:8f2b7f4940b5 274 DS1820_done_flag = true;
pairmand 3:8f2b7f4940b5 275 }
pairmand 3:8f2b7f4940b5 276 return return_value;
pairmand 3:8f2b7f4940b5 277 }
pairmand 3:8f2b7f4940b5 278
pairmand 3:8f2b7f4940b5 279 void DS1820::match_ROM() {
pairmand 3:8f2b7f4940b5 280 // Used to select a specific device
pairmand 3:8f2b7f4940b5 281 int i;
Sissors 5:2cd4928e8147 282 onewire_reset(&this->_datapin);
pairmand 3:8f2b7f4940b5 283 onewire_byte_out( 0x55); //Match ROM command
Sissors 5:2cd4928e8147 284 for (i=0;i<8;i++) {
Sissors 5:2cd4928e8147 285 onewire_byte_out(_ROM[i]);
Sissors 5:2cd4928e8147 286 }
pairmand 3:8f2b7f4940b5 287 }
pairmand 3:8f2b7f4940b5 288
pairmand 3:8f2b7f4940b5 289 void DS1820::skip_ROM() {
Sissors 5:2cd4928e8147 290 onewire_reset(&this->_datapin);
pairmand 3:8f2b7f4940b5 291 onewire_byte_out(0xCC); // Skip ROM command
pairmand 3:8f2b7f4940b5 292 }
pairmand 3:8f2b7f4940b5 293
Sissors 5:2cd4928e8147 294 bool DS1820::ROM_checksum_error(char *_ROM_address) {
Sissors 11:1a3c3002b50c 295 char _CRC=0x00;
pairmand 3:8f2b7f4940b5 296 int i;
pairmand 3:8f2b7f4940b5 297 for(i=0;i<7;i++) // Only going to shift the lower 7 bytes
Sissors 11:1a3c3002b50c 298 _CRC = CRC_byte(_CRC, _ROM_address[i]);
pairmand 3:8f2b7f4940b5 299 // After 7 bytes CRC should equal the 8th byte (ROM CRC)
Sissors 11:1a3c3002b50c 300 return (_CRC!=_ROM_address[7]); // will return true if there is a CRC checksum mis-match
pairmand 3:8f2b7f4940b5 301 }
pairmand 3:8f2b7f4940b5 302
pairmand 3:8f2b7f4940b5 303 bool DS1820::RAM_checksum_error() {
Sissors 11:1a3c3002b50c 304 char _CRC=0x00;
pairmand 3:8f2b7f4940b5 305 int i;
pairmand 3:8f2b7f4940b5 306 for(i=0;i<8;i++) // Only going to shift the lower 8 bytes
Sissors 11:1a3c3002b50c 307 _CRC = CRC_byte(_CRC, RAM[i]);
pairmand 3:8f2b7f4940b5 308 // After 8 bytes CRC should equal the 9th byte (RAM CRC)
Sissors 11:1a3c3002b50c 309 return (_CRC!=RAM[8]); // will return true if there is a CRC checksum mis-match
pairmand 3:8f2b7f4940b5 310 }
pairmand 3:8f2b7f4940b5 311
Sissors 11:1a3c3002b50c 312 char DS1820::CRC_byte (char _CRC, char byte ) {
pairmand 3:8f2b7f4940b5 313 int j;
pairmand 3:8f2b7f4940b5 314 for(j=0;j<8;j++) {
Sissors 11:1a3c3002b50c 315 if ((byte & 0x01 ) ^ (_CRC & 0x01)) {
pairmand 3:8f2b7f4940b5 316 // DATA ^ LSB CRC = 1
Sissors 11:1a3c3002b50c 317 _CRC = _CRC>>1;
pairmand 3:8f2b7f4940b5 318 // Set the MSB to 1
Sissors 11:1a3c3002b50c 319 _CRC = _CRC | 0x80;
pairmand 3:8f2b7f4940b5 320 // Check bit 3
Sissors 11:1a3c3002b50c 321 if (_CRC & 0x04) {
Sissors 11:1a3c3002b50c 322 _CRC = _CRC & 0xFB; // Bit 3 is set, so clear it
pairmand 3:8f2b7f4940b5 323 } else {
Sissors 11:1a3c3002b50c 324 _CRC = _CRC | 0x04; // Bit 3 is clear, so set it
pairmand 3:8f2b7f4940b5 325 }
pairmand 3:8f2b7f4940b5 326 // Check bit 4
Sissors 11:1a3c3002b50c 327 if (_CRC & 0x08) {
Sissors 11:1a3c3002b50c 328 _CRC = _CRC & 0xF7; // Bit 4 is set, so clear it
pairmand 3:8f2b7f4940b5 329 } else {
Sissors 11:1a3c3002b50c 330 _CRC = _CRC | 0x08; // Bit 4 is clear, so set it
pairmand 3:8f2b7f4940b5 331 }
pairmand 3:8f2b7f4940b5 332 } else {
pairmand 3:8f2b7f4940b5 333 // DATA ^ LSB CRC = 0
Sissors 11:1a3c3002b50c 334 _CRC = _CRC>>1;
pairmand 3:8f2b7f4940b5 335 // clear MSB
Sissors 11:1a3c3002b50c 336 _CRC = _CRC & 0x7F;
pairmand 3:8f2b7f4940b5 337 // No need to check bits, with DATA ^ LSB CRC = 0, they will remain unchanged
pairmand 3:8f2b7f4940b5 338 }
pairmand 3:8f2b7f4940b5 339 byte = byte>>1;
pairmand 3:8f2b7f4940b5 340 }
Sissors 11:1a3c3002b50c 341 return _CRC;
pairmand 3:8f2b7f4940b5 342 }
pairmand 3:8f2b7f4940b5 343
Sissors 5:2cd4928e8147 344 int DS1820::convertTemperature(bool wait, devices device) {
pairmand 3:8f2b7f4940b5 345 // Convert temperature into scratchpad RAM for all devices at once
pairmand 3:8f2b7f4940b5 346 int delay_time = 750; // Default delay time
pairmand 3:8f2b7f4940b5 347 char resolution;
pairmand 3:8f2b7f4940b5 348 if (device==all_devices)
pairmand 3:8f2b7f4940b5 349 skip_ROM(); // Skip ROM command, will convert for ALL devices
pairmand 3:8f2b7f4940b5 350 else {
pairmand 3:8f2b7f4940b5 351 match_ROM();
Sissors 5:2cd4928e8147 352 if ((FAMILY_CODE == FAMILY_CODE_DS18B20 ) || (FAMILY_CODE == FAMILY_CODE_DS1822 )) {
pairmand 3:8f2b7f4940b5 353 resolution = RAM[4] & 0x60;
pairmand 3:8f2b7f4940b5 354 if (resolution == 0x00) // 9 bits
pairmand 3:8f2b7f4940b5 355 delay_time = 94;
pairmand 3:8f2b7f4940b5 356 if (resolution == 0x20) // 10 bits
pairmand 3:8f2b7f4940b5 357 delay_time = 188;
pairmand 3:8f2b7f4940b5 358 if (resolution == 0x40) // 11 bits. Note 12bits uses the 750ms default
pairmand 3:8f2b7f4940b5 359 delay_time = 375;
pairmand 3:8f2b7f4940b5 360 }
pairmand 3:8f2b7f4940b5 361 }
Sissors 5:2cd4928e8147 362
pairmand 3:8f2b7f4940b5 363 onewire_byte_out( 0x44); // perform temperature conversion
pairmand 3:8f2b7f4940b5 364 if (_parasite_power) {
Sissors 5:2cd4928e8147 365 if (_power_mosfet) {
Sissors 5:2cd4928e8147 366 _parasitepin = _power_polarity; // Parasite power strong pullup
Sissors 5:2cd4928e8147 367 wait_ms(delay_time);
Sissors 5:2cd4928e8147 368 _parasitepin = !_power_polarity;
Sissors 5:2cd4928e8147 369 delay_time = 0;
Sissors 5:2cd4928e8147 370 } else {
Sissors 5:2cd4928e8147 371 _datapin.output();
Sissors 5:2cd4928e8147 372 _datapin.write(1);
Sissors 5:2cd4928e8147 373 wait_ms(delay_time);
Sissors 5:2cd4928e8147 374 _datapin.input();
Sissors 5:2cd4928e8147 375 }
pairmand 3:8f2b7f4940b5 376 } else {
pairmand 3:8f2b7f4940b5 377 if (wait) {
pairmand 3:8f2b7f4940b5 378 wait_ms(delay_time);
pairmand 3:8f2b7f4940b5 379 delay_time = 0;
pairmand 3:8f2b7f4940b5 380 }
pairmand 3:8f2b7f4940b5 381 }
pairmand 3:8f2b7f4940b5 382 return delay_time;
pairmand 3:8f2b7f4940b5 383 }
pairmand 3:8f2b7f4940b5 384
pairmand 3:8f2b7f4940b5 385 void DS1820::read_RAM() {
pairmand 3:8f2b7f4940b5 386 // This will copy the DS1820's 9 bytes of RAM data
pairmand 3:8f2b7f4940b5 387 // into the objects RAM array. Functions that use
pairmand 3:8f2b7f4940b5 388 // RAM values will automaticly call this procedure.
pairmand 3:8f2b7f4940b5 389 int i;
pairmand 3:8f2b7f4940b5 390 match_ROM(); // Select this device
pairmand 3:8f2b7f4940b5 391 onewire_byte_out( 0xBE); //Read Scratchpad command
pairmand 3:8f2b7f4940b5 392 for(i=0;i<9;i++) {
pairmand 3:8f2b7f4940b5 393 RAM[i] = onewire_byte_in();
pairmand 3:8f2b7f4940b5 394 }
pairmand 3:8f2b7f4940b5 395 // if (!RAM_checksum_error())
pairmand 3:8f2b7f4940b5 396 // crcerr = 1;
pairmand 3:8f2b7f4940b5 397 }
pairmand 3:8f2b7f4940b5 398
Sissors 5:2cd4928e8147 399 bool DS1820::setResolution(unsigned int resolution) {
pairmand 3:8f2b7f4940b5 400 bool answer = false;
pairmand 3:8f2b7f4940b5 401 resolution = resolution - 9;
pairmand 3:8f2b7f4940b5 402 if (resolution < 4) {
pairmand 3:8f2b7f4940b5 403 resolution = resolution<<5; // align the bits
pairmand 3:8f2b7f4940b5 404 RAM[4] = (RAM[4] & 0x60) | resolution; // mask out old data, insert new
pairmand 3:8f2b7f4940b5 405 write_scratchpad ((RAM[2]<<8) + RAM[3]);
pairmand 3:8f2b7f4940b5 406 // store_scratchpad (DS1820::this_device); // Need to test if this is required
pairmand 3:8f2b7f4940b5 407 answer = true;
pairmand 3:8f2b7f4940b5 408 }
pairmand 3:8f2b7f4940b5 409 return answer;
pairmand 3:8f2b7f4940b5 410 }
pairmand 3:8f2b7f4940b5 411
pairmand 3:8f2b7f4940b5 412 void DS1820::write_scratchpad(int data) {
pairmand 3:8f2b7f4940b5 413 RAM[3] = data;
pairmand 3:8f2b7f4940b5 414 RAM[2] = data>>8;
pairmand 3:8f2b7f4940b5 415 match_ROM();
pairmand 3:8f2b7f4940b5 416 onewire_byte_out(0x4E); // Copy scratchpad into DS1820 ram memory
pairmand 3:8f2b7f4940b5 417 onewire_byte_out(RAM[2]); // T(H)
pairmand 3:8f2b7f4940b5 418 onewire_byte_out(RAM[3]); // T(L)
Sissors 5:2cd4928e8147 419 if ((FAMILY_CODE == FAMILY_CODE_DS18B20 ) || (FAMILY_CODE == FAMILY_CODE_DS1822 )) {
pairmand 3:8f2b7f4940b5 420 onewire_byte_out(RAM[4]); // Configuration register
pairmand 3:8f2b7f4940b5 421 }
pairmand 3:8f2b7f4940b5 422 }
pairmand 3:8f2b7f4940b5 423
pairmand 3:8f2b7f4940b5 424 float DS1820::temperature(char scale) {
pairmand 3:8f2b7f4940b5 425 // The data specs state that count_per_degree should be 0x10 (16), I found my devices
pairmand 3:8f2b7f4940b5 426 // to have a count_per_degree of 0x4B (75). With the standard resolution of 1/2 deg C
pairmand 3:8f2b7f4940b5 427 // this allowed an expanded resolution of 1/150th of a deg C. I wouldn't rely on this
pairmand 3:8f2b7f4940b5 428 // being super acurate, but it does allow for a smooth display in the 1/10ths of a
pairmand 3:8f2b7f4940b5 429 // deg C or F scales.
pairmand 3:8f2b7f4940b5 430 float answer, remaining_count, count_per_degree;
pairmand 3:8f2b7f4940b5 431 int reading;
pairmand 3:8f2b7f4940b5 432 read_RAM();
pairmand 3:8f2b7f4940b5 433 if (RAM_checksum_error())
pairmand 3:8f2b7f4940b5 434 // Indicate we got a CRC error
Sissors 7:58b61681818f 435 answer = invalid_conversion;
pairmand 3:8f2b7f4940b5 436 else {
pairmand 3:8f2b7f4940b5 437 reading = (RAM[1] << 8) + RAM[0];
pairmand 3:8f2b7f4940b5 438 if (reading & 0x8000) { // negative degrees C
pairmand 3:8f2b7f4940b5 439 reading = 0-((reading ^ 0xffff) + 1); // 2's comp then convert to signed int
pairmand 3:8f2b7f4940b5 440 }
pairmand 3:8f2b7f4940b5 441 answer = reading +0.0; // convert to floating point
Sissors 5:2cd4928e8147 442 if ((FAMILY_CODE == FAMILY_CODE_DS18B20 ) || (FAMILY_CODE == FAMILY_CODE_DS1822 )) {
Sissors 11:1a3c3002b50c 443 answer = answer / 16.0f;
pairmand 3:8f2b7f4940b5 444 }
pairmand 3:8f2b7f4940b5 445 else {
pairmand 3:8f2b7f4940b5 446 remaining_count = RAM[6];
pairmand 3:8f2b7f4940b5 447 count_per_degree = RAM[7];
Sissors 11:1a3c3002b50c 448 answer = floor(answer/2.0f) - 0.25f + (count_per_degree - remaining_count) / count_per_degree;
pairmand 3:8f2b7f4940b5 449 }
florian 10:d297ce9ce422 450 if (scale=='F' or scale=='f')
pairmand 3:8f2b7f4940b5 451 // Convert to deg F
Sissors 11:1a3c3002b50c 452 answer = answer * 9.0f / 5.0f + 32.0f;
pairmand 3:8f2b7f4940b5 453 }
pairmand 3:8f2b7f4940b5 454 return answer;
pairmand 3:8f2b7f4940b5 455 }
pairmand 3:8f2b7f4940b5 456
pairmand 3:8f2b7f4940b5 457 bool DS1820::read_power_supply(devices device) {
pairmand 3:8f2b7f4940b5 458 // This will return true if the device (or all devices) are Vcc powered
pairmand 3:8f2b7f4940b5 459 // This will return false if the device (or ANY device) is parasite powered
pairmand 3:8f2b7f4940b5 460 if (device==all_devices)
pairmand 3:8f2b7f4940b5 461 skip_ROM(); // Skip ROM command, will poll for any device using parasite power
pairmand 3:8f2b7f4940b5 462 else
pairmand 3:8f2b7f4940b5 463 match_ROM();
pairmand 3:8f2b7f4940b5 464 onewire_byte_out(0xB4); // Read power supply command
Sissors 5:2cd4928e8147 465 return onewire_bit_in(&this->_datapin);
pairmand 3:8f2b7f4940b5 466 }
pairmand 3:8f2b7f4940b5 467
pairmand 3:8f2b7f4940b5 468