Remote serial port server (adapter) UART to 1-wire application

 

PS304 Yes 4 Passageway 1Wire Interface , Multiple can be connected to each interface at the same time 1Wire chip （ Or equipment ）. have 64 position ID Search function ; It has the adaptive function of long-distance lines .

ID Search and cable adaptation detection
Send... To the module [WIRE1][FIND], The module returns all the... Mounted on the search line 1Wire chip ID And the output , Every ID Occupy 8 byte . give an example ： Search channel 1 On all the 1Wire chip , The module returns the following information ：S2SREC 28 AA 32 B9 21 20 03 94 2D 85 00 10 20 00 00 7A Total return 16 Bytes of data , Every ID8 byte , So channel 1 There are two on 1Wire chip
chip 1ID： 28 AA 32 B9 21 20 03 94
chip 2ID： 2D 85 00 10 20 00 00 7A

During search , The module will detect the cable parameters , Automatically complete cable adaptation correction . When the 1Wire When there is an error in chip operation , Or change the line length , Or when replacing the cable , The above search operation should be repeated , To get the real-time number of chips and chips ID And the adaptability of the module to the cable performance . notes ： generally speaking , The longer the cable, the longer the search process takes .

DS18B20 Temperature sensor
DS18B20 yes 1Wire Interface temperature sensor , Can be realized 12 Temperature conversion and output function of bit accuracy . The use method is briefly described as follows .
（1） Start a temperature conversion
Send to the chip 0xCC 0x44, S2S Agreement for ： [WIRE1][START][WT2H]CC 44
（2） Reading temperature
Send to the chip 0xCC 0xBE, Then read 2 Bytes .S2S Agreement for ： [WIRE][START][WT2H]CC BE[RD2N]

Module return ： S2SREC C8 010x01C8 Convert to 10 Into the system for 456, according to DS18B20 Data book description , The number of *0.0625=28.5℃.
（3） Reading temperature （ Using chip only ID）
[WIRE][START][WT10H]55 28 AA 32 B9 21 20 03 94 BE[RD2N]（ The underlined part is the known chip ID）
Module return ： S2SREC C8 01
0x01C8 Convert to 10 Into the system for 456, according to DS18B20 Data book description , The number of *0.0625=28.5℃.

DS2431 Memory chips
DS2431 Is a 1024 position 1-Wire EEPROM chip , from Four memory pages , each page 256 position . The data is written into a 8 In byte register , After verification, it is copied to EEPROM Memory . It is characterized by , The four memory pages are independent of each other , You can set write protection or EPROM Simulation mode . Yes 2431 The read-write access of the chip must be in 8 Bytes and the starting address must be 8 Multiple .
（1） Read EEPROM
Send to the chip 0xCC 0xF0+ Two byte starting address , Then read 8 Bytes of data .
example ： Read EEPROM The address of 0~8, [WIRE][START][WT4H]CC F0 00 00[RD8N]
Module return ： S2SREC 31 32 33 34 35 36 37 38
（2） Write EEPROM
2431 The write operation of is divided into write register and register synchronization to EEPROM Two big steps . Write register ： Send to the chip 0xCC 0x0F+ Two byte starting address +8 Bytes of data .[WIRE][START][WT4H]CC 0F 00 00[WT8H]31 32 33 34 35 36 37 38[RD2N]
Module return ： S2SREC 52 D7（0x52D7 Is sent for this data CRC Check the data ）
Read register ： Send to the chip 0xCC 0xAA, read 13 byte （3 A register +8 Byte register data +2 byte CRC）
[WIRE][START][WT2H]CC AA[RD3N][DELAY1][RD10N]
Module return ： S2SREC 00 00 07 31 32 33 34 35 36 37 38 66 B2
The register is synchronized to EEPROM： Send to the chip 0xCC 0x55+ Two byte starting address +0x07
Module return ： S2SREC AA（0xAA Indicates the synchronization is successful ）