| Line No. | Rev | Author | Line |
|---|---|---|---|
| 1 | 6 | kaklik | //***************************************************************************** |
| 2 | // File Name : ds18b20.c |
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| 3 | // Title : Dallas 1-Wire DS18B20 Temperature Sensor Library |
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| 4 | // Revision : 3 |
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| 5 | // Notes : |
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| 6 | // Target MCU : Atmel AVR series |
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| 7 | // Editor Tabs : 4 |
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| 8 | // |
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| 9 | //***************************************************************************** |
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| 10 | |||
| 11 | //----- Include Files --------------------------------------------------------- |
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| 12 | #include "rprintf.h" // include rprintf function library |
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| 13 | #include "dallas.h" // include dallas support |
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| 14 | #include "ds18b20.h" // include ds18b20 support |
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| 15 | |||
| 16 | void ds18b20Init(void) |
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| 17 | { |
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| 18 | // initialize the 1-wire |
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| 19 | dallasInit(); |
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| 20 | } |
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| 21 | |||
| 22 | u08 ds18b20Setup(dallas_rom_id_T* rom_id, u08 resolution, s08 alarm_low, s08 alarm_high) |
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| 23 | { |
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| 24 | u08 error; |
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| 25 | |||
| 26 | // check resolution |
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| 27 | if ((resolution < DS18B20_RES_MIN) || (resolution > DS18B20_RES_MAX)) |
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| 28 | return DALLAS_RESOLUTION_ERROR; |
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| 29 | |||
| 30 | // check address |
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| 31 | error = dallasAddressCheck(rom_id, DS18B20_FAMILY); |
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| 32 | if (error != DALLAS_NO_ERROR) |
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| 33 | return error; |
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| 34 | |||
| 35 | // reset and select node |
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| 36 | error = dallasMatchROM(rom_id); |
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| 37 | if (error != DALLAS_NO_ERROR) |
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| 38 | return error; |
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| 39 | |||
| 40 | // starts writting at address 0x02, T_H |
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| 41 | dallasWriteByte(DS18B20_WRITE_SCRATCHPAD); |
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| 42 | dallasWriteByte(alarm_high); |
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| 43 | dallasWriteByte(alarm_low); |
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| 44 | |||
| 45 | // convert resolution to bitmask |
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| 46 | // valid value are 9-12 encoded as 0-4, resolution stored in bits 5&6 and bits 0-4 are always one |
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| 47 | resolution = ((resolution - 9) << 5) | 0x60; |
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| 48 | dallasWriteByte(resolution); |
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| 49 | |||
| 50 | // reset and select node |
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| 51 | error = dallasMatchROM(rom_id); |
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| 52 | if (error != DALLAS_NO_ERROR) |
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| 53 | return error; |
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| 54 | |||
| 55 | // start reading at address 0x00 |
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| 56 | dallasWriteByte(DS18B20_READ_SCRATCHPAD); |
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| 57 | |||
| 58 | dallasReadByte(); // 0x00, temp lsb |
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| 59 | dallasReadByte(); // 0x01, temp msb |
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| 60 | |||
| 61 | // verify the data |
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| 62 | if ((s08)dallasReadByte() != alarm_high) // 0x02, alarm high |
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| 63 | return DALLAS_VERIFY_ERROR; |
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| 64 | if ((s08)dallasReadByte() != alarm_low) // 0x03, alarm low |
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| 65 | return DALLAS_VERIFY_ERROR; |
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| 66 | if (dallasReadByte() != resolution) // 0x04, resolution |
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| 67 | return DALLAS_VERIFY_ERROR; |
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| 68 | |||
| 69 | return DALLAS_NO_ERROR; |
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| 70 | } |
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| 71 | |||
| 72 | u08 ds18b20Start(dallas_rom_id_T* rom_id) |
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| 73 | { |
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| 74 | u08 error; |
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| 75 | |||
| 76 | // check address |
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| 77 | error = dallasAddressCheck(rom_id, DS18B20_FAMILY); |
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| 78 | if (error != DALLAS_NO_ERROR) |
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| 79 | return error; |
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| 80 | |||
| 81 | // reset and select node |
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| 82 | error = dallasMatchROM(rom_id); |
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| 83 | if (error != DALLAS_NO_ERROR) |
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| 84 | return error; |
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| 85 | |||
| 86 | // send convert command |
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| 87 | dallasWriteByte(DS18B20_CONVERT_TEMP); |
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| 88 | |||
| 89 | return DALLAS_NO_ERROR; |
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| 90 | } |
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| 91 | |||
| 92 | /*------ DallasTempGetResult ------*/ |
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| 93 | u08 ds18b20Result(dallas_rom_id_T* rom_id, u16 *result) |
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| 94 | { |
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| 95 | u08 error; |
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| 96 | |||
| 97 | union int16_var_U |
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| 98 | { |
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| 99 | u16 i16; |
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| 100 | u08 i08[2]; |
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| 101 | } int16_var; |
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| 102 | |||
| 103 | // check address |
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| 104 | error = dallasAddressCheck(rom_id, DS18B20_FAMILY); |
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| 105 | if (error != DALLAS_NO_ERROR) |
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| 106 | return error; |
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| 107 | |||
| 108 | // reset and select node |
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| 109 | error = dallasMatchROM(rom_id); |
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| 110 | if (error != DALLAS_NO_ERROR) |
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| 111 | return error; |
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| 112 | |||
| 113 | // send command |
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| 114 | dallasWriteByte(DS18B20_READ_SCRATCHPAD); |
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| 115 | |||
| 116 | // read results 1 byte at a time |
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| 117 | int16_var.i08[0] = dallasReadByte(); |
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| 118 | int16_var.i08[1] = dallasReadByte(); |
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| 119 | *result = int16_var.i16; |
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| 120 | |||
| 121 | return DALLAS_NO_ERROR; |
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| 122 | } |
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| 123 | |||
| 124 | u08 ds18b20StartAndResult(dallas_rom_id_T* rom_id, u16 *result) |
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| 125 | { |
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| 126 | u08 error; |
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| 127 | |||
| 128 | // start |
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| 129 | error = ds18b20Start(rom_id); |
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| 130 | if(error != DALLAS_NO_ERROR) |
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| 131 | return error; |
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| 132 | |||
| 133 | // wait |
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| 134 | dallasWaitUntilDone(); |
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| 135 | |||
| 136 | // return any errors - results passed by reference |
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| 137 | return ds18b20Result(rom_id,result); |
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| 138 | } |
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| 139 | |||
| 140 | void ds18b20Print(u16 result, u08 resolution) |
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| 141 | { |
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| 142 | // print raw value |
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| 143 | rprintfProgStrM(" 0x"); |
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| 144 | rprintfu16(result); |
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| 145 | rprintfChar(' '); |
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| 146 | |||
| 147 | // print real temp |
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| 148 | rprintfNum(10, 4, TRUE , ' ', result>>4); |
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| 149 | rprintf("."); |
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| 150 | rprintfNum(10, 4, FALSE, '0', (10000*((u32)(result&0x000F)))/16 ); |
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| 151 | rprintfProgStrM(" C"); |
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| 152 | } |
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| 153 | |||
| 154 | /* OLD VERSION |
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| 155 | |||
| 156 | void ds18b20Print(u16 result, u08 resolution) |
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| 157 | { |
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| 158 | u08 numerator; |
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| 159 | |||
| 160 | // print header |
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| 161 | rprintfProgStrM(" 0x"); |
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| 162 | rprintfu16(result); |
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| 163 | rprintfChar(' '); |
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| 164 | |||
| 165 | // extract fractional part |
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| 166 | numerator = result & 0x000F; |
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| 167 | |||
| 168 | // extract integer part |
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| 169 | result >>= 4; |
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| 170 | |||
| 171 | // deal with negative numbers |
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| 172 | if ((s08)result < 0) |
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| 173 | { |
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| 174 | // for negative fractions |
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| 175 | if (numerator) |
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| 176 | { |
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| 177 | numerator = 16-numerator; // fractions are reversed |
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| 178 | ++result; // the integer is one more than 2's complement |
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| 179 | if (!(s08)result) // between -1 and 0 |
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| 180 | rprintfChar('-'); // we have to take care of the negative sign |
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| 181 | } |
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| 182 | } |
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| 183 | |||
| 184 | // print integer part (signed) |
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| 185 | rprintfNum(10,4,1,'0',(s08)result); |
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| 186 | rprintfChar(' '); |
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| 187 | |||
| 188 | //Print fractional part. use numerator for numerator, resolution for denomiator |
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| 189 | // bit resolution setup mask degree resolution |
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| 190 | // -------------- ---------- ----------------- |
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| 191 | // 9 0x00 1/2 |
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| 192 | // 10 0x20 1/4 |
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| 193 | // 11 0x40 1/8 |
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| 194 | // 12 0x60 1/16 |
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| 195 | numerator >>= (12-resolution); // scale fractional part of result to resolution |
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| 196 | resolution = 2 << (resolution - 9); // create denominator as 2^(res-9) |
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| 197 | rprintfNum(10,3,0,0,numerator); |
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| 198 | rprintfChar('/'); |
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| 199 | rprintfNum(10,3,0,0,resolution); |
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| 200 | } |
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| 201 | */ |
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