Yet another DS1820 lib, but this one is make in sweat of struggling with other ones. It's a fork really of <insert original as mbed doesn't track idk why> with *added capability* of not blocking.
DS1820.cpp@0:3968e3a2e047, 2017-08-30 (annotated)
- Committer:
- amateusz
- Date:
- Wed Aug 30 21:15:06 2017 +0000
- Revision:
- 0:3968e3a2e047
- Child:
- 1:1020ba9ab5d2
Fixed changing resolution (bitmask); Changed behaviour. No need to "convert" any more. Just get temperature().; Also added internal Ticker, which updates temperature at given rate in background
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
amateusz | 0:3968e3a2e047 | 1 | #include "DS1820.h" |
amateusz | 0:3968e3a2e047 | 2 | #include "mbed.h" |
amateusz | 0:3968e3a2e047 | 3 | |
amateusz | 0:3968e3a2e047 | 4 | // Global variables shared between all DS1820 objects |
amateusz | 0:3968e3a2e047 | 5 | bool DS1820_done_flag; |
amateusz | 0:3968e3a2e047 | 6 | int DS1820_last_descrepancy; |
amateusz | 0:3968e3a2e047 | 7 | char DS1820_search_ROM[8]; |
amateusz | 0:3968e3a2e047 | 8 | |
amateusz | 0:3968e3a2e047 | 9 | |
amateusz | 0:3968e3a2e047 | 10 | DS1820::DS1820 (PinName data_pin, PinName power_pin) : _datapin(data_pin), _parasitepin(power_pin) |
amateusz | 0:3968e3a2e047 | 11 | { |
amateusz | 0:3968e3a2e047 | 12 | int byte_counter; |
amateusz | 0:3968e3a2e047 | 13 | |
amateusz | 0:3968e3a2e047 | 14 | _last_temperature = NULL; |
amateusz | 0:3968e3a2e047 | 15 | _parasite_power = true; |
amateusz | 0:3968e3a2e047 | 16 | for(byte_counter=0; byte_counter<8; byte_counter++) |
amateusz | 0:3968e3a2e047 | 17 | ROM[byte_counter] = 0xFF; |
amateusz | 0:3968e3a2e047 | 18 | for(byte_counter=0; byte_counter<9; byte_counter++) |
amateusz | 0:3968e3a2e047 | 19 | RAM[byte_counter] = 0x00; |
amateusz | 0:3968e3a2e047 | 20 | } |
amateusz | 0:3968e3a2e047 | 21 | DS1820::DS1820 (PinName data_pin) : _datapin(data_pin), _parasitepin(NC) |
amateusz | 0:3968e3a2e047 | 22 | { |
amateusz | 0:3968e3a2e047 | 23 | int byte_counter; |
amateusz | 0:3968e3a2e047 | 24 | |
amateusz | 0:3968e3a2e047 | 25 | _last_temperature = NULL; |
amateusz | 0:3968e3a2e047 | 26 | _parasite_power = false; |
amateusz | 0:3968e3a2e047 | 27 | for(byte_counter=0; byte_counter<8; byte_counter++) |
amateusz | 0:3968e3a2e047 | 28 | ROM[byte_counter] = 0xFF; |
amateusz | 0:3968e3a2e047 | 29 | for(byte_counter=0; byte_counter<9; byte_counter++) |
amateusz | 0:3968e3a2e047 | 30 | RAM[byte_counter] = 0x00; |
amateusz | 0:3968e3a2e047 | 31 | } |
amateusz | 0:3968e3a2e047 | 32 | |
amateusz | 0:3968e3a2e047 | 33 | void DS1820::_auto_convert_temperature() |
amateusz | 0:3968e3a2e047 | 34 | { |
amateusz | 0:3968e3a2e047 | 35 | convert_temperature(DS1820::this_device); |
amateusz | 0:3968e3a2e047 | 36 | } |
amateusz | 0:3968e3a2e047 | 37 | |
amateusz | 0:3968e3a2e047 | 38 | void DS1820::enable_auto_convert(float interval) |
amateusz | 0:3968e3a2e047 | 39 | { |
amateusz | 0:3968e3a2e047 | 40 | _autoConvert.attach(this, &DS1820::_auto_convert_temperature, interval); |
amateusz | 0:3968e3a2e047 | 41 | } |
amateusz | 0:3968e3a2e047 | 42 | |
amateusz | 0:3968e3a2e047 | 43 | bool DS1820::onewire_reset() |
amateusz | 0:3968e3a2e047 | 44 | { |
amateusz | 0:3968e3a2e047 | 45 | // This will return false if no devices are present on the data bus |
amateusz | 0:3968e3a2e047 | 46 | bool presence=false; |
amateusz | 0:3968e3a2e047 | 47 | _datapin.output(); |
amateusz | 0:3968e3a2e047 | 48 | _datapin.mode(PullUp); |
amateusz | 0:3968e3a2e047 | 49 | _datapin = 0; // bring low for 500 us |
amateusz | 0:3968e3a2e047 | 50 | wait_us(500); |
amateusz | 0:3968e3a2e047 | 51 | _datapin.input(); // let the data line float high |
amateusz | 0:3968e3a2e047 | 52 | _datapin.mode(PullUp); |
amateusz | 0:3968e3a2e047 | 53 | wait_us(90); // wait 90us |
amateusz | 0:3968e3a2e047 | 54 | if (_datapin.read()==0) // see if any devices are pulling the data line low |
amateusz | 0:3968e3a2e047 | 55 | presence=true; |
amateusz | 0:3968e3a2e047 | 56 | wait_us(410); |
amateusz | 0:3968e3a2e047 | 57 | return presence; |
amateusz | 0:3968e3a2e047 | 58 | } |
amateusz | 0:3968e3a2e047 | 59 | |
amateusz | 0:3968e3a2e047 | 60 | void DS1820::onewire_bit_out (bool bit_data) |
amateusz | 0:3968e3a2e047 | 61 | { |
amateusz | 0:3968e3a2e047 | 62 | _datapin.output(); |
amateusz | 0:3968e3a2e047 | 63 | _datapin = 0; |
amateusz | 0:3968e3a2e047 | 64 | wait_us(5); |
amateusz | 0:3968e3a2e047 | 65 | if (bit_data) { |
amateusz | 0:3968e3a2e047 | 66 | _datapin.input(); // bring data line high |
amateusz | 0:3968e3a2e047 | 67 | _datapin.mode(PullUp); |
amateusz | 0:3968e3a2e047 | 68 | wait_us(55); |
amateusz | 0:3968e3a2e047 | 69 | } else { |
amateusz | 0:3968e3a2e047 | 70 | wait_us(55); // keep data line low |
amateusz | 0:3968e3a2e047 | 71 | _datapin.input(); |
amateusz | 0:3968e3a2e047 | 72 | _datapin.mode(PullUp); |
amateusz | 0:3968e3a2e047 | 73 | } |
amateusz | 0:3968e3a2e047 | 74 | } |
amateusz | 0:3968e3a2e047 | 75 | |
amateusz | 0:3968e3a2e047 | 76 | void DS1820::onewire_byte_out(char data) // output data character (least sig bit first). |
amateusz | 0:3968e3a2e047 | 77 | { |
amateusz | 0:3968e3a2e047 | 78 | int n; |
amateusz | 0:3968e3a2e047 | 79 | for (n=0; n<8; n++) { |
amateusz | 0:3968e3a2e047 | 80 | onewire_bit_out(data & 0x01); |
amateusz | 0:3968e3a2e047 | 81 | data = data >> 1; // now the next bit is in the least sig bit position. |
amateusz | 0:3968e3a2e047 | 82 | } |
amateusz | 0:3968e3a2e047 | 83 | } |
amateusz | 0:3968e3a2e047 | 84 | |
amateusz | 0:3968e3a2e047 | 85 | bool DS1820::onewire_bit_in() |
amateusz | 0:3968e3a2e047 | 86 | { |
amateusz | 0:3968e3a2e047 | 87 | bool answer; |
amateusz | 0:3968e3a2e047 | 88 | _datapin.output(); |
amateusz | 0:3968e3a2e047 | 89 | _datapin = 0; |
amateusz | 0:3968e3a2e047 | 90 | wait_us(5); |
amateusz | 0:3968e3a2e047 | 91 | _datapin.input(); |
amateusz | 0:3968e3a2e047 | 92 | _datapin.mode(PullUp); |
amateusz | 0:3968e3a2e047 | 93 | wait_us(5); |
amateusz | 0:3968e3a2e047 | 94 | answer = _datapin.read(); |
amateusz | 0:3968e3a2e047 | 95 | wait_us(50); |
amateusz | 0:3968e3a2e047 | 96 | return answer; |
amateusz | 0:3968e3a2e047 | 97 | } |
amateusz | 0:3968e3a2e047 | 98 | |
amateusz | 0:3968e3a2e047 | 99 | char DS1820::onewire_byte_in() // read byte, least sig byte first |
amateusz | 0:3968e3a2e047 | 100 | { |
amateusz | 0:3968e3a2e047 | 101 | char answer = 0x00; |
amateusz | 0:3968e3a2e047 | 102 | int i; |
amateusz | 0:3968e3a2e047 | 103 | for (i=0; i<8; i++) { |
amateusz | 0:3968e3a2e047 | 104 | answer = answer >> 1; // shift over to make room for the next bit |
amateusz | 0:3968e3a2e047 | 105 | if (onewire_bit_in()) |
amateusz | 0:3968e3a2e047 | 106 | answer = answer | 0x80; // if the data port is high, make this bit a 1 |
amateusz | 0:3968e3a2e047 | 107 | } |
amateusz | 0:3968e3a2e047 | 108 | return answer; |
amateusz | 0:3968e3a2e047 | 109 | } |
amateusz | 0:3968e3a2e047 | 110 | |
amateusz | 0:3968e3a2e047 | 111 | bool DS1820::search_ROM() |
amateusz | 0:3968e3a2e047 | 112 | { |
amateusz | 0:3968e3a2e047 | 113 | return search_ROM_routine(0xF0); // Search ROM command |
amateusz | 0:3968e3a2e047 | 114 | } |
amateusz | 0:3968e3a2e047 | 115 | |
amateusz | 0:3968e3a2e047 | 116 | bool DS1820::search_alarm() |
amateusz | 0:3968e3a2e047 | 117 | { |
amateusz | 0:3968e3a2e047 | 118 | return search_ROM_routine(0xEC); // Search Alarm command |
amateusz | 0:3968e3a2e047 | 119 | } |
amateusz | 0:3968e3a2e047 | 120 | |
amateusz | 0:3968e3a2e047 | 121 | bool DS1820::search_ROM_routine(char command) |
amateusz | 0:3968e3a2e047 | 122 | { |
amateusz | 0:3968e3a2e047 | 123 | extern bool DS1820_done_flag; |
amateusz | 0:3968e3a2e047 | 124 | extern int DS1820_last_descrepancy; |
amateusz | 0:3968e3a2e047 | 125 | extern char DS1820_search_ROM[8]; |
amateusz | 0:3968e3a2e047 | 126 | int descrepancy_marker, ROM_bit_index; |
amateusz | 0:3968e3a2e047 | 127 | bool return_value, Bit_A, Bit_B; |
amateusz | 0:3968e3a2e047 | 128 | char byte_counter, bit_mask; |
amateusz | 0:3968e3a2e047 | 129 | |
amateusz | 0:3968e3a2e047 | 130 | return_value=false; |
amateusz | 0:3968e3a2e047 | 131 | if (!DS1820_done_flag) { |
amateusz | 0:3968e3a2e047 | 132 | if (!onewire_reset()) { |
amateusz | 0:3968e3a2e047 | 133 | DS1820_last_descrepancy = 0; // no devices present |
amateusz | 0:3968e3a2e047 | 134 | } else { |
amateusz | 0:3968e3a2e047 | 135 | ROM_bit_index=1; |
amateusz | 0:3968e3a2e047 | 136 | descrepancy_marker=0; |
amateusz | 0:3968e3a2e047 | 137 | onewire_byte_out(command); // Search ROM command or Search Alarm command |
amateusz | 0:3968e3a2e047 | 138 | byte_counter = 0; |
amateusz | 0:3968e3a2e047 | 139 | bit_mask = 0x01; |
amateusz | 0:3968e3a2e047 | 140 | while (ROM_bit_index<=64) { |
amateusz | 0:3968e3a2e047 | 141 | Bit_A = onewire_bit_in(); |
amateusz | 0:3968e3a2e047 | 142 | Bit_B = onewire_bit_in(); |
amateusz | 0:3968e3a2e047 | 143 | if (Bit_A & Bit_B) { |
amateusz | 0:3968e3a2e047 | 144 | descrepancy_marker = 0; // data read error, this should never happen |
amateusz | 0:3968e3a2e047 | 145 | ROM_bit_index = 0xFF; |
amateusz | 0:3968e3a2e047 | 146 | } else { |
amateusz | 0:3968e3a2e047 | 147 | if (Bit_A | Bit_B) { |
amateusz | 0:3968e3a2e047 | 148 | // Set ROM bit to Bit_A |
amateusz | 0:3968e3a2e047 | 149 | if (Bit_A) { |
amateusz | 0:3968e3a2e047 | 150 | DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] | bit_mask; // Set ROM bit to one |
amateusz | 0:3968e3a2e047 | 151 | } else { |
amateusz | 0:3968e3a2e047 | 152 | DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] & ~bit_mask; // Set ROM bit to zero |
amateusz | 0:3968e3a2e047 | 153 | } |
amateusz | 0:3968e3a2e047 | 154 | } else { |
amateusz | 0:3968e3a2e047 | 155 | // both bits A and B are low, so there are two or more devices present |
amateusz | 0:3968e3a2e047 | 156 | if ( ROM_bit_index == DS1820_last_descrepancy ) { |
amateusz | 0:3968e3a2e047 | 157 | DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] | bit_mask; // Set ROM bit to one |
amateusz | 0:3968e3a2e047 | 158 | } else { |
amateusz | 0:3968e3a2e047 | 159 | if ( ROM_bit_index > DS1820_last_descrepancy ) { |
amateusz | 0:3968e3a2e047 | 160 | DS1820_search_ROM[byte_counter] = DS1820_search_ROM[byte_counter] & ~bit_mask; // Set ROM bit to zero |
amateusz | 0:3968e3a2e047 | 161 | descrepancy_marker = ROM_bit_index; |
amateusz | 0:3968e3a2e047 | 162 | } else { |
amateusz | 0:3968e3a2e047 | 163 | if (( DS1820_search_ROM[byte_counter] & bit_mask) == 0x00 ) |
amateusz | 0:3968e3a2e047 | 164 | descrepancy_marker = ROM_bit_index; |
amateusz | 0:3968e3a2e047 | 165 | } |
amateusz | 0:3968e3a2e047 | 166 | } |
amateusz | 0:3968e3a2e047 | 167 | } |
amateusz | 0:3968e3a2e047 | 168 | onewire_bit_out (DS1820_search_ROM[byte_counter] & bit_mask); |
amateusz | 0:3968e3a2e047 | 169 | ROM_bit_index++; |
amateusz | 0:3968e3a2e047 | 170 | if (bit_mask & 0x80) { |
amateusz | 0:3968e3a2e047 | 171 | byte_counter++; |
amateusz | 0:3968e3a2e047 | 172 | bit_mask = 0x01; |
amateusz | 0:3968e3a2e047 | 173 | } else { |
amateusz | 0:3968e3a2e047 | 174 | bit_mask = bit_mask << 1; |
amateusz | 0:3968e3a2e047 | 175 | } |
amateusz | 0:3968e3a2e047 | 176 | } |
amateusz | 0:3968e3a2e047 | 177 | } |
amateusz | 0:3968e3a2e047 | 178 | DS1820_last_descrepancy = descrepancy_marker; |
amateusz | 0:3968e3a2e047 | 179 | if (ROM_bit_index != 0xFF) { |
amateusz | 0:3968e3a2e047 | 180 | for(byte_counter=0; byte_counter<8; byte_counter++) |
amateusz | 0:3968e3a2e047 | 181 | ROM[byte_counter] = DS1820_search_ROM[byte_counter]; |
amateusz | 0:3968e3a2e047 | 182 | return_value = true; |
amateusz | 0:3968e3a2e047 | 183 | } |
amateusz | 0:3968e3a2e047 | 184 | } |
amateusz | 0:3968e3a2e047 | 185 | if (DS1820_last_descrepancy == 0) |
amateusz | 0:3968e3a2e047 | 186 | DS1820_done_flag = true; |
amateusz | 0:3968e3a2e047 | 187 | } |
amateusz | 0:3968e3a2e047 | 188 | return return_value; |
amateusz | 0:3968e3a2e047 | 189 | } |
amateusz | 0:3968e3a2e047 | 190 | |
amateusz | 0:3968e3a2e047 | 191 | void DS1820::search_ROM_setup() |
amateusz | 0:3968e3a2e047 | 192 | { |
amateusz | 0:3968e3a2e047 | 193 | extern bool DS1820_done_flag; |
amateusz | 0:3968e3a2e047 | 194 | extern int DS1820_last_descrepancy; |
amateusz | 0:3968e3a2e047 | 195 | extern char DS1820_search_ROM[8]; |
amateusz | 0:3968e3a2e047 | 196 | DS1820_done_flag = false; |
amateusz | 0:3968e3a2e047 | 197 | DS1820_last_descrepancy = 0; |
amateusz | 0:3968e3a2e047 | 198 | int i; |
amateusz | 0:3968e3a2e047 | 199 | for (i=0; i<8; i++) |
amateusz | 0:3968e3a2e047 | 200 | DS1820_search_ROM[i]=0x00; |
amateusz | 0:3968e3a2e047 | 201 | } |
amateusz | 0:3968e3a2e047 | 202 | |
amateusz | 0:3968e3a2e047 | 203 | void DS1820::read_ROM() |
amateusz | 0:3968e3a2e047 | 204 | { |
amateusz | 0:3968e3a2e047 | 205 | // NOTE: This command can only be used when there is one DS1820 on the bus. If this command |
amateusz | 0:3968e3a2e047 | 206 | // is used when there is more than one slave present on the bus, a data collision will occur |
amateusz | 0:3968e3a2e047 | 207 | // when all the DS1820s attempt to respond at the same time. |
amateusz | 0:3968e3a2e047 | 208 | int i; |
amateusz | 0:3968e3a2e047 | 209 | onewire_reset(); |
amateusz | 0:3968e3a2e047 | 210 | onewire_byte_out(0x33); // Read ROM id |
amateusz | 0:3968e3a2e047 | 211 | for (i=0; i<8; i++) |
amateusz | 0:3968e3a2e047 | 212 | ROM[i]=onewire_byte_in(); |
amateusz | 0:3968e3a2e047 | 213 | } |
amateusz | 0:3968e3a2e047 | 214 | |
amateusz | 0:3968e3a2e047 | 215 | void DS1820::match_ROM() |
amateusz | 0:3968e3a2e047 | 216 | { |
amateusz | 0:3968e3a2e047 | 217 | // Used to select a specific device |
amateusz | 0:3968e3a2e047 | 218 | int i; |
amateusz | 0:3968e3a2e047 | 219 | onewire_reset(); |
amateusz | 0:3968e3a2e047 | 220 | onewire_byte_out( 0x55); //Match ROM command |
amateusz | 0:3968e3a2e047 | 221 | for (i=0; i<8; i++) |
amateusz | 0:3968e3a2e047 | 222 | onewire_byte_out(ROM[i]); |
amateusz | 0:3968e3a2e047 | 223 | } |
amateusz | 0:3968e3a2e047 | 224 | |
amateusz | 0:3968e3a2e047 | 225 | void DS1820::skip_ROM() |
amateusz | 0:3968e3a2e047 | 226 | { |
amateusz | 0:3968e3a2e047 | 227 | onewire_reset(); |
amateusz | 0:3968e3a2e047 | 228 | onewire_byte_out(0xCC); // Skip ROM command |
amateusz | 0:3968e3a2e047 | 229 | } |
amateusz | 0:3968e3a2e047 | 230 | |
amateusz | 0:3968e3a2e047 | 231 | bool DS1820::ROM_checksum_error() |
amateusz | 0:3968e3a2e047 | 232 | { |
amateusz | 0:3968e3a2e047 | 233 | char xCRC=0x00; |
amateusz | 0:3968e3a2e047 | 234 | int i; |
amateusz | 0:3968e3a2e047 | 235 | for(i=0; i<7; i++) // Only going to shift the lower 7 bytes |
amateusz | 0:3968e3a2e047 | 236 | xCRC = CRC_byte(xCRC, ROM[i]); |
amateusz | 0:3968e3a2e047 | 237 | // After 7 bytes CRC should equal the 8th byte (ROM CRC) |
amateusz | 0:3968e3a2e047 | 238 | return (xCRC!=ROM[7]); // will return true if there is a CRC checksum error |
amateusz | 0:3968e3a2e047 | 239 | } |
amateusz | 0:3968e3a2e047 | 240 | |
amateusz | 0:3968e3a2e047 | 241 | bool DS1820::RAM_checksum_error() |
amateusz | 0:3968e3a2e047 | 242 | { |
amateusz | 0:3968e3a2e047 | 243 | char xCRC=0x00; |
amateusz | 0:3968e3a2e047 | 244 | int i; |
amateusz | 0:3968e3a2e047 | 245 | read_RAM(); |
amateusz | 0:3968e3a2e047 | 246 | for(i=0; i<8; i++) // Only going to shift the lower 8 bytes |
amateusz | 0:3968e3a2e047 | 247 | xCRC = CRC_byte(xCRC, RAM[i]); |
amateusz | 0:3968e3a2e047 | 248 | // After 8 bytes CRC should equal the 9th byte (RAM CRC) |
amateusz | 0:3968e3a2e047 | 249 | return (xCRC!=RAM[8]); // will return true if there is a CRC checksum error |
amateusz | 0:3968e3a2e047 | 250 | } |
amateusz | 0:3968e3a2e047 | 251 | |
amateusz | 0:3968e3a2e047 | 252 | char DS1820::CRC_byte (char xCRC, char byte ) |
amateusz | 0:3968e3a2e047 | 253 | { |
amateusz | 0:3968e3a2e047 | 254 | int j; |
amateusz | 0:3968e3a2e047 | 255 | for(j=0; j<8; j++) { |
amateusz | 0:3968e3a2e047 | 256 | if ((byte & 0x01 ) ^ (xCRC & 0x01)) { |
amateusz | 0:3968e3a2e047 | 257 | // DATA ^ LSB CRC = 1 |
amateusz | 0:3968e3a2e047 | 258 | xCRC = xCRC>>1; |
amateusz | 0:3968e3a2e047 | 259 | // Set the MSB to 1 |
amateusz | 0:3968e3a2e047 | 260 | xCRC = xCRC | 0x80; |
amateusz | 0:3968e3a2e047 | 261 | // Check bit 3 |
amateusz | 0:3968e3a2e047 | 262 | if (xCRC & 0x04) { |
amateusz | 0:3968e3a2e047 | 263 | xCRC = xCRC & 0xFB; // Bit 3 is set, so clear it |
amateusz | 0:3968e3a2e047 | 264 | } else { |
amateusz | 0:3968e3a2e047 | 265 | xCRC = xCRC | 0x04; // Bit 3 is clear, so set it |
amateusz | 0:3968e3a2e047 | 266 | } |
amateusz | 0:3968e3a2e047 | 267 | // Check bit 4 |
amateusz | 0:3968e3a2e047 | 268 | if (xCRC & 0x08) { |
amateusz | 0:3968e3a2e047 | 269 | xCRC = xCRC & 0xF7; // Bit 4 is set, so clear it |
amateusz | 0:3968e3a2e047 | 270 | } else { |
amateusz | 0:3968e3a2e047 | 271 | xCRC = xCRC | 0x08; // Bit 4 is clear, so set it |
amateusz | 0:3968e3a2e047 | 272 | } |
amateusz | 0:3968e3a2e047 | 273 | } else { |
amateusz | 0:3968e3a2e047 | 274 | // DATA ^ LSB xCRC = 0 |
amateusz | 0:3968e3a2e047 | 275 | xCRC = xCRC>>1; |
amateusz | 0:3968e3a2e047 | 276 | // clear MSB |
amateusz | 0:3968e3a2e047 | 277 | xCRC = xCRC & 0x7F; |
amateusz | 0:3968e3a2e047 | 278 | // No need to check bits, with DATA ^ LSB xCRC = 0, they will remain unchanged |
amateusz | 0:3968e3a2e047 | 279 | } |
amateusz | 0:3968e3a2e047 | 280 | byte = byte>>1; |
amateusz | 0:3968e3a2e047 | 281 | } |
amateusz | 0:3968e3a2e047 | 282 | return xCRC; |
amateusz | 0:3968e3a2e047 | 283 | } |
amateusz | 0:3968e3a2e047 | 284 | |
amateusz | 0:3968e3a2e047 | 285 | void DS1820::convert_temperature(devices device) |
amateusz | 0:3968e3a2e047 | 286 | { |
amateusz | 0:3968e3a2e047 | 287 | // Convert temperature into scratchpad RAM for all devices at once |
amateusz | 0:3968e3a2e047 | 288 | int delay_time = 750; // Default delay time |
amateusz | 0:3968e3a2e047 | 289 | char resolution; |
amateusz | 0:3968e3a2e047 | 290 | if (device==all_devices) |
amateusz | 0:3968e3a2e047 | 291 | skip_ROM(); // Skip ROM command, will convert for ALL devices |
amateusz | 0:3968e3a2e047 | 292 | else { |
amateusz | 0:3968e3a2e047 | 293 | match_ROM(); |
amateusz | 0:3968e3a2e047 | 294 | if (FAMILY_CODE == FAMILY_CODE_DS18B20 ) { |
amateusz | 0:3968e3a2e047 | 295 | resolution = RAM[4] & 0x60; |
amateusz | 0:3968e3a2e047 | 296 | if (resolution == 0x00) // 9 bits |
amateusz | 0:3968e3a2e047 | 297 | delay_time = 94; |
amateusz | 0:3968e3a2e047 | 298 | if (resolution == 0x20) // 10 bits |
amateusz | 0:3968e3a2e047 | 299 | delay_time = 188; |
amateusz | 0:3968e3a2e047 | 300 | if (resolution == 0x40) // 11 bits. Note 12bits uses the 750ms default |
amateusz | 0:3968e3a2e047 | 301 | delay_time = 375; |
amateusz | 0:3968e3a2e047 | 302 | } |
amateusz | 0:3968e3a2e047 | 303 | } |
amateusz | 0:3968e3a2e047 | 304 | onewire_byte_out( 0x44); // perform temperature conversion |
amateusz | 0:3968e3a2e047 | 305 | if (_parasite_power) |
amateusz | 0:3968e3a2e047 | 306 | _parasitepin = 1; // Parasite power strong pullup |
amateusz | 0:3968e3a2e047 | 307 | wait_ms(delay_time); |
amateusz | 0:3968e3a2e047 | 308 | // Timeout auto_get_new_temperature; |
amateusz | 0:3968e3a2e047 | 309 | // float timeout_time = ((float)delay_time)/1000.0; |
amateusz | 0:3968e3a2e047 | 310 | // auto_get_new_temperature.attach(this, &DS1820::_temperature, timeout_time); // update _last_temperture automagically |
amateusz | 0:3968e3a2e047 | 311 | _temperature(); |
amateusz | 0:3968e3a2e047 | 312 | |
amateusz | 0:3968e3a2e047 | 313 | if (_parasite_power) |
amateusz | 0:3968e3a2e047 | 314 | _parasitepin = 0; |
amateusz | 0:3968e3a2e047 | 315 | } |
amateusz | 0:3968e3a2e047 | 316 | |
amateusz | 0:3968e3a2e047 | 317 | void DS1820::read_RAM() |
amateusz | 0:3968e3a2e047 | 318 | { |
amateusz | 0:3968e3a2e047 | 319 | // This will copy the DS1820's 9 bytes of RAM data |
amateusz | 0:3968e3a2e047 | 320 | // into the objects RAM array. Functions that use |
amateusz | 0:3968e3a2e047 | 321 | // RAM values will automaticly call this procedure. |
amateusz | 0:3968e3a2e047 | 322 | int i; |
amateusz | 0:3968e3a2e047 | 323 | match_ROM(); // Select this device |
amateusz | 0:3968e3a2e047 | 324 | onewire_byte_out( 0xBE); //Read Scratchpad command |
amateusz | 0:3968e3a2e047 | 325 | for(i=0; i<9; i++) { |
amateusz | 0:3968e3a2e047 | 326 | RAM[i] = onewire_byte_in(); |
amateusz | 0:3968e3a2e047 | 327 | } |
amateusz | 0:3968e3a2e047 | 328 | } |
amateusz | 0:3968e3a2e047 | 329 | |
amateusz | 0:3968e3a2e047 | 330 | bool DS1820::set_configuration_bits(unsigned int resolution, devices device) |
amateusz | 0:3968e3a2e047 | 331 | { |
amateusz | 0:3968e3a2e047 | 332 | bool answer = false; |
amateusz | 0:3968e3a2e047 | 333 | resolution = resolution - 9; |
amateusz | 0:3968e3a2e047 | 334 | if (resolution < 4) { |
amateusz | 0:3968e3a2e047 | 335 | if (device==all_devices) |
amateusz | 0:3968e3a2e047 | 336 | skip_ROM(); |
amateusz | 0:3968e3a2e047 | 337 | else |
amateusz | 0:3968e3a2e047 | 338 | match_ROM(); |
amateusz | 0:3968e3a2e047 | 339 | resolution = resolution<<5; // align the bits |
amateusz | 0:3968e3a2e047 | 340 | RAM[4] = (RAM[4] & 0b00011111) | resolution; // mask out old data, insert new |
amateusz | 0:3968e3a2e047 | 341 | write_scratchpad ((RAM[2]<<8) + RAM[3]); |
amateusz | 0:3968e3a2e047 | 342 | // store_scratchpad (DS1820::this_device); // Need to test if this is required |
amateusz | 0:3968e3a2e047 | 343 | answer = true; |
amateusz | 0:3968e3a2e047 | 344 | } |
amateusz | 0:3968e3a2e047 | 345 | return answer; |
amateusz | 0:3968e3a2e047 | 346 | } |
amateusz | 0:3968e3a2e047 | 347 | |
amateusz | 0:3968e3a2e047 | 348 | int DS1820::read_scratchpad() |
amateusz | 0:3968e3a2e047 | 349 | { |
amateusz | 0:3968e3a2e047 | 350 | int answer; |
amateusz | 0:3968e3a2e047 | 351 | read_RAM(); |
amateusz | 0:3968e3a2e047 | 352 | answer = (RAM[2]<<8) + RAM[3]; |
amateusz | 0:3968e3a2e047 | 353 | return answer; |
amateusz | 0:3968e3a2e047 | 354 | } |
amateusz | 0:3968e3a2e047 | 355 | |
amateusz | 0:3968e3a2e047 | 356 | void DS1820::write_scratchpad(int data) |
amateusz | 0:3968e3a2e047 | 357 | { |
amateusz | 0:3968e3a2e047 | 358 | RAM[3] = data; |
amateusz | 0:3968e3a2e047 | 359 | RAM[2] = data>>8; |
amateusz | 0:3968e3a2e047 | 360 | match_ROM(); |
amateusz | 0:3968e3a2e047 | 361 | onewire_byte_out(0x4E); // Copy scratchpad into DS1820 ram memory |
amateusz | 0:3968e3a2e047 | 362 | onewire_byte_out(RAM[2]); // T(H) |
amateusz | 0:3968e3a2e047 | 363 | onewire_byte_out(RAM[3]); // T(L) |
amateusz | 0:3968e3a2e047 | 364 | if ( FAMILY_CODE == FAMILY_CODE_DS18B20 ) { |
amateusz | 0:3968e3a2e047 | 365 | onewire_byte_out(RAM[4]); // Configuration register |
amateusz | 0:3968e3a2e047 | 366 | } |
amateusz | 0:3968e3a2e047 | 367 | } |
amateusz | 0:3968e3a2e047 | 368 | |
amateusz | 0:3968e3a2e047 | 369 | void DS1820::store_scratchpad(devices device) |
amateusz | 0:3968e3a2e047 | 370 | { |
amateusz | 0:3968e3a2e047 | 371 | if (device==all_devices) |
amateusz | 0:3968e3a2e047 | 372 | skip_ROM(); // Skip ROM command, will store for ALL devices |
amateusz | 0:3968e3a2e047 | 373 | else |
amateusz | 0:3968e3a2e047 | 374 | match_ROM(); |
amateusz | 0:3968e3a2e047 | 375 | onewire_byte_out(0x48); // Write scratchpad into E2 command |
amateusz | 0:3968e3a2e047 | 376 | if (_parasite_power) |
amateusz | 0:3968e3a2e047 | 377 | _parasitepin=1; |
amateusz | 0:3968e3a2e047 | 378 | wait_ms(10); // Parasite power strong pullup for 10ms |
amateusz | 0:3968e3a2e047 | 379 | if (_parasite_power) |
amateusz | 0:3968e3a2e047 | 380 | _parasitepin=0; |
amateusz | 0:3968e3a2e047 | 381 | } |
amateusz | 0:3968e3a2e047 | 382 | |
amateusz | 0:3968e3a2e047 | 383 | int DS1820::recall_scratchpad(devices device) |
amateusz | 0:3968e3a2e047 | 384 | { |
amateusz | 0:3968e3a2e047 | 385 | // This copies the E2 values into the DS1820's memory. |
amateusz | 0:3968e3a2e047 | 386 | // If you specify all_devices this will return zero, otherwise |
amateusz | 0:3968e3a2e047 | 387 | // it will return the value of the scratchpad memory. |
amateusz | 0:3968e3a2e047 | 388 | int answer=0; |
amateusz | 0:3968e3a2e047 | 389 | if (device==all_devices) |
amateusz | 0:3968e3a2e047 | 390 | skip_ROM(); // Skip ROM command, will recall for ALL devices |
amateusz | 0:3968e3a2e047 | 391 | else |
amateusz | 0:3968e3a2e047 | 392 | match_ROM(); |
amateusz | 0:3968e3a2e047 | 393 | onewire_byte_out(0xB8); // Recall E2 data to scratchpad command |
amateusz | 0:3968e3a2e047 | 394 | wait_ms(10); // not sure I like polling for completion |
amateusz | 0:3968e3a2e047 | 395 | // it could cause an infinite loop |
amateusz | 0:3968e3a2e047 | 396 | if (device==DS1820::this_device) { |
amateusz | 0:3968e3a2e047 | 397 | read_RAM(); |
amateusz | 0:3968e3a2e047 | 398 | answer = read_scratchpad(); |
amateusz | 0:3968e3a2e047 | 399 | } |
amateusz | 0:3968e3a2e047 | 400 | return answer; |
amateusz | 0:3968e3a2e047 | 401 | } |
amateusz | 0:3968e3a2e047 | 402 | void DS1820::_temperature() |
amateusz | 0:3968e3a2e047 | 403 | { |
amateusz | 0:3968e3a2e047 | 404 | char scale = 'c'; |
amateusz | 0:3968e3a2e047 | 405 | float answer, remaining_count, count_per_degree; |
amateusz | 0:3968e3a2e047 | 406 | int reading; |
amateusz | 0:3968e3a2e047 | 407 | read_RAM(); |
amateusz | 0:3968e3a2e047 | 408 | reading = (RAM[1] << 8) + RAM[0]; |
amateusz | 0:3968e3a2e047 | 409 | if (reading & 0x8000) { // negative degrees C |
amateusz | 0:3968e3a2e047 | 410 | reading = 0-((reading ^ 0xffff) + 1); // 2's comp then convert to signed int |
amateusz | 0:3968e3a2e047 | 411 | } |
amateusz | 0:3968e3a2e047 | 412 | answer = reading +0.0; // convert to floating point |
amateusz | 0:3968e3a2e047 | 413 | if ( FAMILY_CODE == FAMILY_CODE_DS18B20 ) { |
amateusz | 0:3968e3a2e047 | 414 | answer = answer / 8.0; |
amateusz | 0:3968e3a2e047 | 415 | } else { |
amateusz | 0:3968e3a2e047 | 416 | remaining_count = RAM[6]; |
amateusz | 0:3968e3a2e047 | 417 | count_per_degree = RAM[7]; |
amateusz | 0:3968e3a2e047 | 418 | answer = answer - 0.25 + (count_per_degree - remaining_count) / count_per_degree; |
amateusz | 0:3968e3a2e047 | 419 | } |
amateusz | 0:3968e3a2e047 | 420 | |
amateusz | 0:3968e3a2e047 | 421 | if (scale=='C' or scale=='c') |
amateusz | 0:3968e3a2e047 | 422 | answer = answer / 2.0; |
amateusz | 0:3968e3a2e047 | 423 | else |
amateusz | 0:3968e3a2e047 | 424 | // Convert to deg F |
amateusz | 0:3968e3a2e047 | 425 | answer = answer * 9.0 / 10.0 + 32.0; |
amateusz | 0:3968e3a2e047 | 426 | // return answer; |
amateusz | 0:3968e3a2e047 | 427 | _last_temperature = answer; |
amateusz | 0:3968e3a2e047 | 428 | } |
amateusz | 0:3968e3a2e047 | 429 | |
amateusz | 0:3968e3a2e047 | 430 | float DS1820::temperature(char scale) |
amateusz | 0:3968e3a2e047 | 431 | { |
amateusz | 0:3968e3a2e047 | 432 | // The data specs state that count_per_degree should be 0x10 (16), I found my devices |
amateusz | 0:3968e3a2e047 | 433 | // to have a count_per_degree of 0x4B (75). With the standard resolution of 1/2 deg C |
amateusz | 0:3968e3a2e047 | 434 | // this allowed an expanded resolution of 1/150th of a deg C. I wouldn't rely on this |
amateusz | 0:3968e3a2e047 | 435 | // being super acurate, but it does allow for a smooth display in the 1/10ths of a |
amateusz | 0:3968e3a2e047 | 436 | // deg C or F scales. |
amateusz | 0:3968e3a2e047 | 437 | if (_last_temperature == NULL) { |
amateusz | 0:3968e3a2e047 | 438 | convert_temperature(); |
amateusz | 0:3968e3a2e047 | 439 | wait_ms(800); |
amateusz | 0:3968e3a2e047 | 440 | } |
amateusz | 0:3968e3a2e047 | 441 | return _last_temperature; |
amateusz | 0:3968e3a2e047 | 442 | } |
amateusz | 0:3968e3a2e047 | 443 | |
amateusz | 0:3968e3a2e047 | 444 | bool DS1820::read_power_supply(devices device) |
amateusz | 0:3968e3a2e047 | 445 | { |
amateusz | 0:3968e3a2e047 | 446 | // This will return true if the device (or all devices) are Vcc powered |
amateusz | 0:3968e3a2e047 | 447 | // This will return false if the device (or ANY device) is parasite powered |
amateusz | 0:3968e3a2e047 | 448 | if (device==all_devices) |
amateusz | 0:3968e3a2e047 | 449 | skip_ROM(); // Skip ROM command, will poll for any device using parasite power |
amateusz | 0:3968e3a2e047 | 450 | else |
amateusz | 0:3968e3a2e047 | 451 | match_ROM(); |
amateusz | 0:3968e3a2e047 | 452 | onewire_byte_out(0xB4); // Read power supply command |
amateusz | 0:3968e3a2e047 | 453 | return onewire_bit_in(); |
amateusz | 0:3968e3a2e047 | 454 | } |