'SmOuse' / DS1820

Automatic/Manual lights+AC connected over Wifi

Dependents:   ACandLightsandWifi ACandLightsandWifi

Fork of DS1820 by Michael Hagberg

DS1820.cpp@3:cf4f0ea711a7, 2016-06-17 (annotated)

Committer:
jzacaroli
Date:
Fri Jun 17 12:38:22 2016 +0000
Revision:
3:cf4f0ea711a7
Parent:
2:ee820a991b95 
AC + Lights + Wifi

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jzacaroli 3:cf4f0ea711a7 1 #include "DS1820.h"
jzacaroli 3:cf4f0ea711a7 2 #include "mbed.h"
jzacaroli 3:cf4f0ea711a7 3
jzacaroli 3:cf4f0ea711a7 4 // Global variables shared between all DS1820 objects
jzacaroli 3:cf4f0ea711a7 5 bool DS1820_done_flag;
jzacaroli 3:cf4f0ea711a7 6 int DS1820_last_descrepancy;
jzacaroli 3:cf4f0ea711a7 7 char DS1820_search_Rom[8];
jzacaroli 3:cf4f0ea711a7 8
jzacaroli 3:cf4f0ea711a7 9
jzacaroli 3:cf4f0ea711a7 10 DS1820::DS1820 (PinName data_pin, PinName power_pin) : _datapin(data_pin), _parasitepin(power_pin) {
jzacaroli 3:cf4f0ea711a7 11 int byte_counter;
jzacaroli 3:cf4f0ea711a7 12 _parasite_power = true;
jzacaroli 3:cf4f0ea711a7 13 for(byte_counter=0;byte_counter<8;byte_counter++)
jzacaroli 3:cf4f0ea711a7 14 Rom[byte_counter] = 0xFF;
jzacaroli 3:cf4f0ea711a7 15 for(byte_counter=0;byte_counter<9;byte_counter++)
jzacaroli 3:cf4f0ea711a7 16 RAM[byte_counter] = 0x00;
jzacaroli 3:cf4f0ea711a7 17 }
jzacaroli 3:cf4f0ea711a7 18 DS1820::DS1820 (PinName data_pin) : _datapin(data_pin), _parasitepin(NC) {
jzacaroli 3:cf4f0ea711a7 19 int byte_counter;
jzacaroli 3:cf4f0ea711a7 20 _parasite_power = false;
jzacaroli 3:cf4f0ea711a7 21 for(byte_counter=0;byte_counter<8;byte_counter++)
jzacaroli 3:cf4f0ea711a7 22 Rom[byte_counter] = 0xFF;
jzacaroli 3:cf4f0ea711a7 23 for(byte_counter=0;byte_counter<9;byte_counter++)
jzacaroli 3:cf4f0ea711a7 24 RAM[byte_counter] = 0x00;
jzacaroli 3:cf4f0ea711a7 25 }
jzacaroli 3:cf4f0ea711a7 26
jzacaroli 3:cf4f0ea711a7 27 bool DS1820::onewire_reset() {
jzacaroli 3:cf4f0ea711a7 28 // This will return false if no devices are present on the data bus
jzacaroli 3:cf4f0ea711a7 29 bool presence=false;
jzacaroli 3:cf4f0ea711a7 30 _datapin.output();
jzacaroli 3:cf4f0ea711a7 31 _datapin = 0; // bring low for 500 us
jzacaroli 3:cf4f0ea711a7 32 wait_us(500);
jzacaroli 3:cf4f0ea711a7 33 _datapin.input(); // let the data line float high
jzacaroli 3:cf4f0ea711a7 34 wait_us(90); // wait 90us
jzacaroli 3:cf4f0ea711a7 35 if (_datapin.read()==0) // see if any devices are pulling the data line low
jzacaroli 3:cf4f0ea711a7 36 presence=true;
jzacaroli 3:cf4f0ea711a7 37 wait_us(410);
jzacaroli 3:cf4f0ea711a7 38 return presence;
jzacaroli 3:cf4f0ea711a7 39 }
jzacaroli 3:cf4f0ea711a7 40
jzacaroli 3:cf4f0ea711a7 41 void DS1820::onewire_bit_out (bool bit_data) {
jzacaroli 3:cf4f0ea711a7 42 _datapin.output();
jzacaroli 3:cf4f0ea711a7 43 _datapin = 0;
jzacaroli 3:cf4f0ea711a7 44 wait_us(5);
jzacaroli 3:cf4f0ea711a7 45 if (bit_data) {
jzacaroli 3:cf4f0ea711a7 46 _datapin.input(); // bring data line high
jzacaroli 3:cf4f0ea711a7 47 wait_us(55);
jzacaroli 3:cf4f0ea711a7 48 } else {
jzacaroli 3:cf4f0ea711a7 49 wait_us(55); // keep data line low
jzacaroli 3:cf4f0ea711a7 50 _datapin.input();
jzacaroli 3:cf4f0ea711a7 51 }
jzacaroli 3:cf4f0ea711a7 52 }
jzacaroli 3:cf4f0ea711a7 53
jzacaroli 3:cf4f0ea711a7 54 void DS1820::onewire_byte_out(char data) { // output data character (least sig bit first).
jzacaroli 3:cf4f0ea711a7 55 int n;
jzacaroli 3:cf4f0ea711a7 56 for (n=0; n<8; n++) {
jzacaroli 3:cf4f0ea711a7 57 onewire_bit_out(data & 0x01);
jzacaroli 3:cf4f0ea711a7 58 data = data >> 1; // now the next bit is in the least sig bit position.
jzacaroli 3:cf4f0ea711a7 59 }
jzacaroli 3:cf4f0ea711a7 60 }
jzacaroli 3:cf4f0ea711a7 61
jzacaroli 3:cf4f0ea711a7 62 bool DS1820::onewire_bit_in() {
jzacaroli 3:cf4f0ea711a7 63 bool answer;
jzacaroli 3:cf4f0ea711a7 64 _datapin.output();
jzacaroli 3:cf4f0ea711a7 65 _datapin = 0;
jzacaroli 3:cf4f0ea711a7 66 wait_us(5);
jzacaroli 3:cf4f0ea711a7 67 _datapin.input();
jzacaroli 3:cf4f0ea711a7 68 wait_us(5);
jzacaroli 3:cf4f0ea711a7 69 answer = _datapin.read();
jzacaroli 3:cf4f0ea711a7 70 wait_us(50);
jzacaroli 3:cf4f0ea711a7 71 return answer;
jzacaroli 3:cf4f0ea711a7 72 }
jzacaroli 3:cf4f0ea711a7 73
jzacaroli 3:cf4f0ea711a7 74 char DS1820::onewire_byte_in() { // read byte, least sig byte first
jzacaroli 3:cf4f0ea711a7 75 char answer = 0x00;
jzacaroli 3:cf4f0ea711a7 76 int i;
jzacaroli 3:cf4f0ea711a7 77 for (i=0; i<8; i++) {
jzacaroli 3:cf4f0ea711a7 78 answer = answer >> 1; // shift over to make room for the next bit
jzacaroli 3:cf4f0ea711a7 79 if (onewire_bit_in())
jzacaroli 3:cf4f0ea711a7 80 answer = answer | 0x80; // if the data port is high, make this bit a 1
jzacaroli 3:cf4f0ea711a7 81 }
jzacaroli 3:cf4f0ea711a7 82 return answer;
jzacaroli 3:cf4f0ea711a7 83 }
jzacaroli 3:cf4f0ea711a7 84
jzacaroli 3:cf4f0ea711a7 85 bool DS1820::search_Rom() {
jzacaroli 3:cf4f0ea711a7 86 return search_Rom_routine(0xF0); // Search Rom command
jzacaroli 3:cf4f0ea711a7 87 }
jzacaroli 3:cf4f0ea711a7 88
jzacaroli 3:cf4f0ea711a7 89 bool DS1820::search_alarm() {
jzacaroli 3:cf4f0ea711a7 90 return search_Rom_routine(0xEC); // Search Alarm command
jzacaroli 3:cf4f0ea711a7 91 }
jzacaroli 3:cf4f0ea711a7 92
jzacaroli 3:cf4f0ea711a7 93 bool DS1820::search_Rom_routine(char command) {
jzacaroli 3:cf4f0ea711a7 94 extern bool DS1820_done_flag;
jzacaroli 3:cf4f0ea711a7 95 extern int DS1820_last_descrepancy;
jzacaroli 3:cf4f0ea711a7 96 extern char DS1820_search_Rom[8];
jzacaroli 3:cf4f0ea711a7 97 int descrepancy_marker, Rom_bit_index;
jzacaroli 3:cf4f0ea711a7 98 bool return_value, Bit_A, Bit_B;
jzacaroli 3:cf4f0ea711a7 99 char byte_counter, bit_mask;
jzacaroli 3:cf4f0ea711a7 100
jzacaroli 3:cf4f0ea711a7 101 return_value=false;
jzacaroli 3:cf4f0ea711a7 102 if (!DS1820_done_flag) {
jzacaroli 3:cf4f0ea711a7 103 if (!onewire_reset()) {
jzacaroli 3:cf4f0ea711a7 104 DS1820_last_descrepancy = 0; // no devices present
jzacaroli 3:cf4f0ea711a7 105 } else {
jzacaroli 3:cf4f0ea711a7 106 Rom_bit_index=1;
jzacaroli 3:cf4f0ea711a7 107 descrepancy_marker=0;
jzacaroli 3:cf4f0ea711a7 108 onewire_byte_out(command); // Search Rom command or Search Alarm command
jzacaroli 3:cf4f0ea711a7 109 byte_counter = 0;
jzacaroli 3:cf4f0ea711a7 110 bit_mask = 0x01;
jzacaroli 3:cf4f0ea711a7 111 while (Rom_bit_index<=64) {
jzacaroli 3:cf4f0ea711a7 112 Bit_A = onewire_bit_in();
jzacaroli 3:cf4f0ea711a7 113 Bit_B = onewire_bit_in();
jzacaroli 3:cf4f0ea711a7 114 if (Bit_A & Bit_B) {
jzacaroli 3:cf4f0ea711a7 115 descrepancy_marker = 0; // data read error, this should never happen
jzacaroli 3:cf4f0ea711a7 116 Rom_bit_index = 0xFF;
jzacaroli 3:cf4f0ea711a7 117 } else {
jzacaroli 3:cf4f0ea711a7 118 if (Bit_A | Bit_B) {
jzacaroli 3:cf4f0ea711a7 119 // Set Rom bit to Bit_A
jzacaroli 3:cf4f0ea711a7 120 if (Bit_A) {
jzacaroli 3:cf4f0ea711a7 121 DS1820_search_Rom[byte_counter] = DS1820_search_Rom[byte_counter] | bit_mask; // Set Rom bit to one
jzacaroli 3:cf4f0ea711a7 122 } else {
jzacaroli 3:cf4f0ea711a7 123 DS1820_search_Rom[byte_counter] = DS1820_search_Rom[byte_counter] & ~bit_mask; // Set Rom bit to zero
jzacaroli 3:cf4f0ea711a7 124 }
jzacaroli 3:cf4f0ea711a7 125 } else {
jzacaroli 3:cf4f0ea711a7 126 // both bits A and B are low, so there are two or more devices present
jzacaroli 3:cf4f0ea711a7 127 if ( Rom_bit_index == DS1820_last_descrepancy ) {
jzacaroli 3:cf4f0ea711a7 128 DS1820_search_Rom[byte_counter] = DS1820_search_Rom[byte_counter] | bit_mask; // Set Rom bit to one
jzacaroli 3:cf4f0ea711a7 129 } else {
jzacaroli 3:cf4f0ea711a7 130 if ( Rom_bit_index > DS1820_last_descrepancy ) {
jzacaroli 3:cf4f0ea711a7 131 DS1820_search_Rom[byte_counter] = DS1820_search_Rom[byte_counter] & ~bit_mask; // Set Rom bit to zero
jzacaroli 3:cf4f0ea711a7 132 descrepancy_marker = Rom_bit_index;
jzacaroli 3:cf4f0ea711a7 133 } else {
jzacaroli 3:cf4f0ea711a7 134 if (( DS1820_search_Rom[byte_counter] & bit_mask) == 0x00 )
jzacaroli 3:cf4f0ea711a7 135 descrepancy_marker = Rom_bit_index;
jzacaroli 3:cf4f0ea711a7 136 }
jzacaroli 3:cf4f0ea711a7 137 }
jzacaroli 3:cf4f0ea711a7 138 }
jzacaroli 3:cf4f0ea711a7 139 onewire_bit_out (DS1820_search_Rom[byte_counter] & bit_mask);
jzacaroli 3:cf4f0ea711a7 140 Rom_bit_index++;
jzacaroli 3:cf4f0ea711a7 141 if (bit_mask & 0x80) {
jzacaroli 3:cf4f0ea711a7 142 byte_counter++;
jzacaroli 3:cf4f0ea711a7 143 bit_mask = 0x01;
jzacaroli 3:cf4f0ea711a7 144 } else {
jzacaroli 3:cf4f0ea711a7 145 bit_mask = bit_mask << 1;
jzacaroli 3:cf4f0ea711a7 146 }
jzacaroli 3:cf4f0ea711a7 147 }
jzacaroli 3:cf4f0ea711a7 148 }
jzacaroli 3:cf4f0ea711a7 149 DS1820_last_descrepancy = descrepancy_marker;
jzacaroli 3:cf4f0ea711a7 150 if (Rom_bit_index != 0xFF) {
jzacaroli 3:cf4f0ea711a7 151 for(byte_counter=0;byte_counter<8;byte_counter++)
jzacaroli 3:cf4f0ea711a7 152 Rom[byte_counter] = DS1820_search_Rom[byte_counter];
jzacaroli 3:cf4f0ea711a7 153 return_value = true;
jzacaroli 3:cf4f0ea711a7 154 }
jzacaroli 3:cf4f0ea711a7 155 }
jzacaroli 3:cf4f0ea711a7 156 if (DS1820_last_descrepancy == 0)
jzacaroli 3:cf4f0ea711a7 157 DS1820_done_flag = true;
jzacaroli 3:cf4f0ea711a7 158 }
jzacaroli 3:cf4f0ea711a7 159 return return_value;
jzacaroli 3:cf4f0ea711a7 160 }
jzacaroli 3:cf4f0ea711a7 161
jzacaroli 3:cf4f0ea711a7 162 void DS1820::search_Rom_setup() {
jzacaroli 3:cf4f0ea711a7 163 extern bool DS1820_done_flag;
jzacaroli 3:cf4f0ea711a7 164 extern int DS1820_last_descrepancy;
jzacaroli 3:cf4f0ea711a7 165 extern char DS1820_search_Rom[8];
jzacaroli 3:cf4f0ea711a7 166 DS1820_done_flag = false;
jzacaroli 3:cf4f0ea711a7 167 DS1820_last_descrepancy = 0;
jzacaroli 3:cf4f0ea711a7 168 int i;
jzacaroli 3:cf4f0ea711a7 169 for (i=0; i<8; i++)
jzacaroli 3:cf4f0ea711a7 170 DS1820_search_Rom[i]=0x00;
jzacaroli 3:cf4f0ea711a7 171 }
jzacaroli 3:cf4f0ea711a7 172
jzacaroli 3:cf4f0ea711a7 173 void DS1820::read_Rom(){
jzacaroli 3:cf4f0ea711a7 174 // NOTE: This command can only be used when there is one DS1820 on the bus. If this command
jzacaroli 3:cf4f0ea711a7 175 // is used when there is more than one slave present on the bus, a data collision will occur
jzacaroli 3:cf4f0ea711a7 176 // when all the DS1820s attempt to respond at the same time.
jzacaroli 3:cf4f0ea711a7 177 int i;
jzacaroli 3:cf4f0ea711a7 178 onewire_reset();
jzacaroli 3:cf4f0ea711a7 179 onewire_byte_out(0x33); // Read Rom id
jzacaroli 3:cf4f0ea711a7 180 for (i=0; i<8; i++)
jzacaroli 3:cf4f0ea711a7 181 Rom[i]=onewire_byte_in();
jzacaroli 3:cf4f0ea711a7 182 }
jzacaroli 3:cf4f0ea711a7 183
jzacaroli 3:cf4f0ea711a7 184 void DS1820::match_Rom() {
jzacaroli 3:cf4f0ea711a7 185 // Used to select a specific device
jzacaroli 3:cf4f0ea711a7 186 int i;
jzacaroli 3:cf4f0ea711a7 187 onewire_reset();
jzacaroli 3:cf4f0ea711a7 188 onewire_byte_out( 0x55); //Match Rom command
jzacaroli 3:cf4f0ea711a7 189 for (i=0;i<8;i++)
jzacaroli 3:cf4f0ea711a7 190 onewire_byte_out(Rom[i]);
jzacaroli 3:cf4f0ea711a7 191 }
jzacaroli 3:cf4f0ea711a7 192
jzacaroli 3:cf4f0ea711a7 193 void DS1820::skip_Rom() {
jzacaroli 3:cf4f0ea711a7 194 onewire_reset();
jzacaroli 3:cf4f0ea711a7 195 onewire_byte_out(0xCC); // Skip Rom command
jzacaroli 3:cf4f0ea711a7 196 }
jzacaroli 3:cf4f0ea711a7 197
jzacaroli 3:cf4f0ea711a7 198 bool DS1820::Rom_checksum_error() {
jzacaroli 3:cf4f0ea711a7 199 char CRC=0x00;
jzacaroli 3:cf4f0ea711a7 200 int i;
jzacaroli 3:cf4f0ea711a7 201 for(i=0;i<7;i++) // Only going to shift the lower 7 bytes
jzacaroli 3:cf4f0ea711a7 202 CRC = CRC_byte(CRC, Rom[i]);
jzacaroli 3:cf4f0ea711a7 203 // After 7 bytes CRC should equal the 8th byte (Rom CRC)
jzacaroli 3:cf4f0ea711a7 204 return (CRC!=Rom[7]); // will return true if there is a CRC checksum error
jzacaroli 3:cf4f0ea711a7 205 }
jzacaroli 3:cf4f0ea711a7 206
jzacaroli 3:cf4f0ea711a7 207 bool DS1820::RAM_checksum_error() {
jzacaroli 3:cf4f0ea711a7 208 char CRC=0x00;
jzacaroli 3:cf4f0ea711a7 209 int i;
jzacaroli 3:cf4f0ea711a7 210 read_RAM();
jzacaroli 3:cf4f0ea711a7 211 for(i=0;i<8;i++) // Only going to shift the lower 8 bytes
jzacaroli 3:cf4f0ea711a7 212 CRC = CRC_byte(CRC, RAM[i]);
jzacaroli 3:cf4f0ea711a7 213 // After 8 bytes CRC should equal the 9th byte (RAM CRC)
jzacaroli 3:cf4f0ea711a7 214 return (CRC!=RAM[8]); // will return true if there is a CRC checksum error
jzacaroli 3:cf4f0ea711a7 215 }
jzacaroli 3:cf4f0ea711a7 216
jzacaroli 3:cf4f0ea711a7 217 char DS1820::CRC_byte (char CRC, char byte ) {
jzacaroli 3:cf4f0ea711a7 218 int j;
jzacaroli 3:cf4f0ea711a7 219 for(j=0;j<8;j++) {
jzacaroli 3:cf4f0ea711a7 220 if ((byte & 0x01 ) ^ (CRC & 0x01)) {
jzacaroli 3:cf4f0ea711a7 221 // DATA ^ LSB CRC = 1
jzacaroli 3:cf4f0ea711a7 222 CRC = CRC>>1;
jzacaroli 3:cf4f0ea711a7 223 // Set the MSB to 1
jzacaroli 3:cf4f0ea711a7 224 CRC = CRC | 0x80;
jzacaroli 3:cf4f0ea711a7 225 // Check bit 3
jzacaroli 3:cf4f0ea711a7 226 if (CRC & 0x04) {
jzacaroli 3:cf4f0ea711a7 227 CRC = CRC & 0xFB; // Bit 3 is set, so clear it
jzacaroli 3:cf4f0ea711a7 228 } else {
jzacaroli 3:cf4f0ea711a7 229 CRC = CRC | 0x04; // Bit 3 is clear, so set it
jzacaroli 3:cf4f0ea711a7 230 }
jzacaroli 3:cf4f0ea711a7 231 // Check bit 4
jzacaroli 3:cf4f0ea711a7 232 if (CRC & 0x08) {
jzacaroli 3:cf4f0ea711a7 233 CRC = CRC & 0xF7; // Bit 4 is set, so clear it
jzacaroli 3:cf4f0ea711a7 234 } else {
jzacaroli 3:cf4f0ea711a7 235 CRC = CRC | 0x08; // Bit 4 is clear, so set it
jzacaroli 3:cf4f0ea711a7 236 }
jzacaroli 3:cf4f0ea711a7 237 } else {
jzacaroli 3:cf4f0ea711a7 238 // DATA ^ LSB CRC = 0
jzacaroli 3:cf4f0ea711a7 239 CRC = CRC>>1;
jzacaroli 3:cf4f0ea711a7 240 // clear MSB
jzacaroli 3:cf4f0ea711a7 241 CRC = CRC & 0x7F;
jzacaroli 3:cf4f0ea711a7 242 // No need to check bits, with DATA ^ LSB CRC = 0, they will remain unchanged
jzacaroli 3:cf4f0ea711a7 243 }
jzacaroli 3:cf4f0ea711a7 244 byte = byte>>1;
jzacaroli 3:cf4f0ea711a7 245 }
jzacaroli 3:cf4f0ea711a7 246 return CRC;
jzacaroli 3:cf4f0ea711a7 247 }
jzacaroli 3:cf4f0ea711a7 248
jzacaroli 3:cf4f0ea711a7 249 void DS1820::convert_temperature(devices device) {
jzacaroli 3:cf4f0ea711a7 250 // Convert temperature into scratchpad RAM for all devices at once
jzacaroli 3:cf4f0ea711a7 251 int delay_time = 750; // Default delay time
jzacaroli 3:cf4f0ea711a7 252 char resolution;
jzacaroli 3:cf4f0ea711a7 253 if (device==all_devices)
jzacaroli 3:cf4f0ea711a7 254 skip_Rom(); // Skip Rom command, will convert for ALL devices
jzacaroli 3:cf4f0ea711a7 255 else {
jzacaroli 3:cf4f0ea711a7 256 match_Rom();
jzacaroli 3:cf4f0ea711a7 257 if (FAMILY_CODE == FAMILY_CODE_DS18B20 ) {
jzacaroli 3:cf4f0ea711a7 258 resolution = RAM[4] & 0x60;
jzacaroli 3:cf4f0ea711a7 259 if (resolution == 0x00) // 9 bits
jzacaroli 3:cf4f0ea711a7 260 delay_time = 94;
jzacaroli 3:cf4f0ea711a7 261 if (resolution == 0x20) // 10 bits
jzacaroli 3:cf4f0ea711a7 262 delay_time = 188;
jzacaroli 3:cf4f0ea711a7 263 if (resolution == 0x40) // 11 bits. Note 12bits uses the 750ms default
jzacaroli 3:cf4f0ea711a7 264 delay_time = 375;
jzacaroli 3:cf4f0ea711a7 265 }
jzacaroli 3:cf4f0ea711a7 266 }
jzacaroli 3:cf4f0ea711a7 267 onewire_byte_out( 0x44); // perform temperature conversion
jzacaroli 3:cf4f0ea711a7 268 if (_parasite_power)
jzacaroli 3:cf4f0ea711a7 269 _parasitepin = 1; // Parasite power strong pullup
jzacaroli 3:cf4f0ea711a7 270 wait_ms(delay_time);
jzacaroli 3:cf4f0ea711a7 271 if (_parasite_power)
jzacaroli 3:cf4f0ea711a7 272 _parasitepin = 0;
jzacaroli 3:cf4f0ea711a7 273 }
jzacaroli 3:cf4f0ea711a7 274
jzacaroli 3:cf4f0ea711a7 275 void DS1820::read_RAM() {
jzacaroli 3:cf4f0ea711a7 276 // This will copy the DS1820's 9 bytes of RAM data
jzacaroli 3:cf4f0ea711a7 277 // into the objects RAM array. Functions that use
jzacaroli 3:cf4f0ea711a7 278 // RAM values will automaticly call this procedure.
jzacaroli 3:cf4f0ea711a7 279 int i;
jzacaroli 3:cf4f0ea711a7 280 match_Rom(); // Select this device
jzacaroli 3:cf4f0ea711a7 281 onewire_byte_out( 0xBE); //Read Scratchpad command
jzacaroli 3:cf4f0ea711a7 282 for(i=0;i<9;i++) {
jzacaroli 3:cf4f0ea711a7 283 RAM[i] = onewire_byte_in();
jzacaroli 3:cf4f0ea711a7 284 }
jzacaroli 3:cf4f0ea711a7 285 }
jzacaroli 3:cf4f0ea711a7 286
jzacaroli 3:cf4f0ea711a7 287 bool DS1820::set_configuration_bits(unsigned int resolution) {
jzacaroli 3:cf4f0ea711a7 288 bool answer = false;
jzacaroli 3:cf4f0ea711a7 289 resolution = resolution - 9;
jzacaroli 3:cf4f0ea711a7 290 if (resolution < 4) {
jzacaroli 3:cf4f0ea711a7 291 resolution = resolution<<5; // align the bits
jzacaroli 3:cf4f0ea711a7 292 RAM[4] = (RAM[4] & 0x60) | resolution; // mask out old data, insert new
jzacaroli 3:cf4f0ea711a7 293 write_scratchpad ((RAM[2]<<8) + RAM[3]);
jzacaroli 3:cf4f0ea711a7 294 // store_scratchpad (DS1820::this_device); // Need to test if this is required
jzacaroli 3:cf4f0ea711a7 295 answer = true;
jzacaroli 3:cf4f0ea711a7 296 }
jzacaroli 3:cf4f0ea711a7 297 return answer;
jzacaroli 3:cf4f0ea711a7 298 }
jzacaroli 3:cf4f0ea711a7 299
jzacaroli 3:cf4f0ea711a7 300 int DS1820::read_scratchpad() {
jzacaroli 3:cf4f0ea711a7 301 int answer;
jzacaroli 3:cf4f0ea711a7 302 read_RAM();
jzacaroli 3:cf4f0ea711a7 303 answer = (RAM[2]<<8) + RAM[3];
jzacaroli 3:cf4f0ea711a7 304 return answer;
jzacaroli 3:cf4f0ea711a7 305 }
jzacaroli 3:cf4f0ea711a7 306
jzacaroli 3:cf4f0ea711a7 307 void DS1820::write_scratchpad(int data) {
jzacaroli 3:cf4f0ea711a7 308 RAM[3] = data;
jzacaroli 3:cf4f0ea711a7 309 RAM[2] = data>>8;
jzacaroli 3:cf4f0ea711a7 310 match_Rom();
jzacaroli 3:cf4f0ea711a7 311 onewire_byte_out(0x4E); // Copy scratchpad into DS1820 ram memory
jzacaroli 3:cf4f0ea711a7 312 onewire_byte_out(RAM[2]); // T(H)
jzacaroli 3:cf4f0ea711a7 313 onewire_byte_out(RAM[3]); // T(L)
jzacaroli 3:cf4f0ea711a7 314 if ( FAMILY_CODE == FAMILY_CODE_DS18B20 ) {
jzacaroli 3:cf4f0ea711a7 315 onewire_byte_out(RAM[4]); // Configuration register
jzacaroli 3:cf4f0ea711a7 316 }
jzacaroli 3:cf4f0ea711a7 317 }
jzacaroli 3:cf4f0ea711a7 318
jzacaroli 3:cf4f0ea711a7 319 void DS1820::store_scratchpad(devices device) {
jzacaroli 3:cf4f0ea711a7 320 if (device==all_devices)
jzacaroli 3:cf4f0ea711a7 321 skip_Rom(); // Skip Rom command, will store for ALL devices
jzacaroli 3:cf4f0ea711a7 322 else
jzacaroli 3:cf4f0ea711a7 323 match_Rom();
jzacaroli 3:cf4f0ea711a7 324 onewire_byte_out(0x48); // Write scratchpad into E2 command
jzacaroli 3:cf4f0ea711a7 325 if (_parasite_power)
jzacaroli 3:cf4f0ea711a7 326 _parasitepin=1;
jzacaroli 3:cf4f0ea711a7 327 wait_ms(10); // Parasite power strong pullup for 10ms
jzacaroli 3:cf4f0ea711a7 328 if (_parasite_power)
jzacaroli 3:cf4f0ea711a7 329 _parasitepin=0;
jzacaroli 3:cf4f0ea711a7 330 }
jzacaroli 3:cf4f0ea711a7 331
jzacaroli 3:cf4f0ea711a7 332 int DS1820::recall_scratchpad(devices device) {
jzacaroli 3:cf4f0ea711a7 333 // This copies the E2 values into the DS1820's memory.
jzacaroli 3:cf4f0ea711a7 334 // If you specify all_devices this will return zero, otherwise
jzacaroli 3:cf4f0ea711a7 335 // it will return the value of the scratchpad memory.
jzacaroli 3:cf4f0ea711a7 336 int answer=0;
jzacaroli 3:cf4f0ea711a7 337 if (device==all_devices)
jzacaroli 3:cf4f0ea711a7 338 skip_Rom(); // Skip Rom command, will recall for ALL devices
jzacaroli 3:cf4f0ea711a7 339 else
jzacaroli 3:cf4f0ea711a7 340 match_Rom();
jzacaroli 3:cf4f0ea711a7 341 onewire_byte_out(0xB8); // Recall E2 data to scratchpad command
jzacaroli 3:cf4f0ea711a7 342 wait_ms(10); // not sure I like polling for completion
jzacaroli 3:cf4f0ea711a7 343 // it could cause an infinite loop
jzacaroli 3:cf4f0ea711a7 344 if (device==DS1820::this_device) {
jzacaroli 3:cf4f0ea711a7 345 read_RAM();
jzacaroli 3:cf4f0ea711a7 346 answer = read_scratchpad();
jzacaroli 3:cf4f0ea711a7 347 }
jzacaroli 3:cf4f0ea711a7 348 return answer;
jzacaroli 3:cf4f0ea711a7 349 }
jzacaroli 3:cf4f0ea711a7 350
jzacaroli 3:cf4f0ea711a7 351 float DS1820::temperature(char scale) {
jzacaroli 3:cf4f0ea711a7 352 // The data specs state that count_per_degree should be 0x10 (16), I found my devices
jzacaroli 3:cf4f0ea711a7 353 // to have a count_per_degree of 0x4B (75). With the standard resolution of 1/2 deg C
jzacaroli 3:cf4f0ea711a7 354 // this allowed an expanded resolution of 1/150th of a deg C. I wouldn't rely on this
jzacaroli 3:cf4f0ea711a7 355 // being super acurate, but it does allow for a smooth display in the 1/10ths of a
jzacaroli 3:cf4f0ea711a7 356 // deg C or F scales.
jzacaroli 3:cf4f0ea711a7 357 float answer, remaining_count, count_per_degree;
jzacaroli 3:cf4f0ea711a7 358 int reading;
jzacaroli 3:cf4f0ea711a7 359 read_RAM();
jzacaroli 3:cf4f0ea711a7 360 reading = (RAM[1] << 8) + RAM[0];
jzacaroli 3:cf4f0ea711a7 361 if (reading & 0x8000) { // negative degrees C
jzacaroli 3:cf4f0ea711a7 362 reading = 0-((reading ^ 0xffff) + 1); // 2's comp then convert to signed int
jzacaroli 3:cf4f0ea711a7 363 }
jzacaroli 3:cf4f0ea711a7 364 answer = reading +0.0; // convert to floating point
jzacaroli 3:cf4f0ea711a7 365 if ( FAMILY_CODE == FAMILY_CODE_DS18B20 ) {
jzacaroli 3:cf4f0ea711a7 366 answer = answer / 8.0;
jzacaroli 3:cf4f0ea711a7 367 }
jzacaroli 3:cf4f0ea711a7 368 else {
jzacaroli 3:cf4f0ea711a7 369 remaining_count = RAM[6];
jzacaroli 3:cf4f0ea711a7 370 count_per_degree = RAM[7];
jzacaroli 3:cf4f0ea711a7 371 answer = answer - 0.25 + (count_per_degree - remaining_count) / count_per_degree;
jzacaroli 3:cf4f0ea711a7 372 }
jzacaroli 3:cf4f0ea711a7 373 if (scale=='C' or scale=='c')
jzacaroli 3:cf4f0ea711a7 374 answer = answer / 2.0;
jzacaroli 3:cf4f0ea711a7 375 else
jzacaroli 3:cf4f0ea711a7 376 // Convert to deg F
jzacaroli 3:cf4f0ea711a7 377 answer = answer * 9.0 / 10.0 + 32.0;
jzacaroli 3:cf4f0ea711a7 378 return answer;
jzacaroli 3:cf4f0ea711a7 379 }
jzacaroli 3:cf4f0ea711a7 380
jzacaroli 3:cf4f0ea711a7 381 bool DS1820::read_power_supply(devices device) {
jzacaroli 3:cf4f0ea711a7 382 // This will return true if the device (or all devices) are Vcc powered
jzacaroli 3:cf4f0ea711a7 383 // This will return false if the device (or ANY device) is parasite powered
jzacaroli 3:cf4f0ea711a7 384 if (device==all_devices)
jzacaroli 3:cf4f0ea711a7 385 skip_Rom(); // Skip Rom command, will poll for any device using parasite power
jzacaroli 3:cf4f0ea711a7 386 else
jzacaroli 3:cf4f0ea711a7 387 match_Rom();
jzacaroli 3:cf4f0ea711a7 388 onewire_byte_out(0xB4); // Read power supply command
jzacaroli 3:cf4f0ea711a7 389 return onewire_bit_in();
jzacaroli 3:cf4f0ea711a7 390 }