| 1 | /* $Id: ds1820.h,v 1.2 2010/03/23 07:57:04 simimeie Exp $ |
| 2 | * USB interface for ds1820 |
| 3 | * This file handles everything that has to do with the temperature probes. |
| 4 | * (C) Michael "Fox" Meier 2009 |
| 5 | * There are two modes: KISS (keep it simple stupid), activated when you |
| 6 | * define KISS, can only ever support one probe on the bus. When KISS is |
| 7 | * not defined, multiple probes are supported up to a compile time maximum, |
| 8 | * and the bus is searched for probes. |
| 9 | */ |
| 10 | |
| 11 | #ifndef __DS1820_H__ |
| 12 | #define __DS1820_H__ |
| 13 | |
| 14 | #include <inttypes.h> |
| 15 | |
| 16 | /* Number of probes supported */ |
| 17 | #define DS1820_MAXPROBES 4 |
| 18 | |
| 19 | #ifdef KISS /* We can only ever handle one probe in this mode, so override define */ |
| 20 | #undef DS1820_MAXPROBES |
| 21 | #define DS1820_MAXPROBES 1 |
| 22 | #endif |
| 23 | |
| 24 | #define DS1820FLAG_SLOTINUSE 0x01 /* 1 if this slot is in use */ |
| 25 | #define DS1820FLAG_PARASITE 0x02 /* 1 if the device is parasite powered */ |
| 26 | |
| 27 | #define DS1820_CMD_SEARCHROM 0xF0 |
| 28 | #define DS1820_CMD_SKIPROM 0xCC |
| 29 | #define DS1820_CMD_MATCHROM 0x55 |
| 30 | #define DS1820_CMD_READROM 0x33 |
| 31 | #define DS1820_CMD_CONVERTT 0x44 |
| 32 | #define DS1820_CMD_READSCRPAD 0xBE |
| 33 | #define DS1820_CMD_READPOWER 0xB4 |
| 34 | |
| 35 | struct probe { |
| 36 | uint8_t family; |
| 37 | uint8_t serial[6]; |
| 38 | uint8_t flags; |
| 39 | uint8_t lasttemp[2]; /* Temperature we read last */ |
| 40 | uint32_t lastts; /* Timestamp when we last read it */ |
| 41 | }; |
| 42 | |
| 43 | extern struct probe ds1820probes[DS1820_MAXPROBES]; |
| 44 | |
| 45 | /* Inits ds1820 code and bus */ |
| 46 | void ds1820init(void); |
| 47 | |
| 48 | /* Actively pull down the bus. For hard resetting probes that have gone |
| 49 | * bonkers. */ |
| 50 | void ds1820killbus(void); |
| 51 | |
| 52 | /* Scan the bus to find all probes. Populates the ds1820probes array. */ |
| 53 | void ds1820scan(void); |
| 54 | |
| 55 | /* Tells one probe to do temperature conversion. Since that takes |
| 56 | * about 1 second, you will need to wait that long before |
| 57 | * calling ds1820updateprobe. |
| 58 | * the number is the index number for the ds1820probes array. */ |
| 59 | void ds1820queryprobe(uint8_t probenum); |
| 60 | |
| 61 | /* Reads the answer from the probe queried with ds1820queryprobe |
| 62 | * before and updates its data. |
| 63 | * the number is the index number for the ds1820probes array. |
| 64 | * Returns 1 on successful update, 0 otherwise */ |
| 65 | uint8_t ds1820updateprobe(uint8_t probenum); |
| 66 | |
| 67 | #endif /* __DS1820_H__ */ |