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+# onewire Module
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+
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+## ow.check_crc16()
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+Compute the 1-Wire CRC16 and compare it against the received CRC.
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+
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+####Syntax
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+`ow.check_crc16(buf, inverted_crc0, inverted_crc1[, crc])`
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+
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+#### Parameters
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+ - `buf` string value, data to be calculated check sum in string
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+ - `inverted_crc0` LSB of received CRC
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+ - `inverted_crc1` MSB of received CRC
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+ - `crc` CRC starting value (optional)
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+
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+#### Returns
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+`bool` true, if the CRC matches; false for mismatch.
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+
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+## ow.crc16()
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+Compute a Dallas Semiconductor 16 bit CRC. This is required to check the integrity of data received from many 1-Wire devices. Note that the CRC computed here is **not** what you'll get from the 1-Wire network, for two reasons:
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+
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+1. The CRC is transmitted bitwise inverted.
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+2. Depending on the endian-ness of your processor, the binary representation of the two-byte return value may have a different byte order than the two bytes you get from 1-Wire.
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+
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+#### Syntax
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+`ow.crc16(buf[, crc])`
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+
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+#### Parameters
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+ - `buf` string value, data to be calculated check sum in string.
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+ - `crc` CRC starting value (optional)
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+
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+#### Returns
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+`crc16` the CRC16, as defined by Dallas Semiconductor.
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+
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+## ow.crc8()
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+Compute a Dallas Semiconductor 8 bit CRC, these are used in the ROM and scratchpad registers.
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+
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+#### Syntax
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+`ow.crc8(buf)`
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+
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+#### Parameters
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+`buf` string value, data to be calculated check sum in string.
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+
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+#### Returns
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+CRC result as byte.
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+
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+## ow.depower()
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+Stop forcing power onto the bus. You only need to do this if you used the 'power' flag to `ow.write()` or used a `ow.write_bytes()` and aren't about to do another read or write.
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+
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+#### Syntax
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+`ow.depower(pin)`
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+
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+#### Parameters
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+`pin` 1~12, IO index
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+
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+#### Returns
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+`nil`
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+
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+####See also
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+ - [ow.write()](#owwrite)
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+ - [ow.write_bytes()](#owwrite_bytes)
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+
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+## ow.read()
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+Read a byte.
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+
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+####Syntax
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+`ow.read(pin)`
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+
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+#### Parameters
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+`pin` 1~12, IO index
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+
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+#### Returns
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+Byte read from slave device.
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+
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+## ow.read_bytes()
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+Read multi bytes.
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+
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+#### Syntax
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+`ow.read_bytes(pin, size)`
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+
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+#### Parameters
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+ - `pin` 1~12, IO index
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+ - `size` number of bytes to be read from slave device
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+
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+#### Returns
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+`string` bytes read from slave device
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+
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+## ow.reset_search()
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+Clear the search state so that it will start from the beginning again.
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+
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+#### Syntax
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+`ow.reset_search(pin)`
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+
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+#### Parameters
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+`pin` 1~12, IO index
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+
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+#### Returns
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+`nil`
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+
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+## ow.search()
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+Look for the next device.
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+
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+#### Syntax
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+`ow.search(pin)`
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+
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+#### Parameters
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+`pin` 1~12, IO index
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+
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+#### Returns
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+`rom_code` string with length of 8 upon success. It contains the rom code of slave device. Returns `nil` if search was unsuccessful.
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+
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+#### See also
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+[ow.target_search()](#owtargetsearch)
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+
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+## ow.select()
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+Issue a 1-Wire rom select command, make sure you do the `ow.reset(pin)` first.
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+
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+#### Syntax
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+`ow.select(pin, rom)`
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+
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+#### Parameters
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+ - `pin` 1~12, IO index
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+ - `rom` string value, len 8, rom code of the salve device
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+
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+#### Returns
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+`nil`
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+
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+#### Example
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+```lua
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+-- 18b20 Example
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+pin = 9
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+ow.setup(pin)
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+count = 0
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+repeat
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+ count = count + 1
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+ addr = ow.reset_search(pin)
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+ addr = ow.search(pin)
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+ tmr.wdclr()
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+until (addr ~= nil) or (count > 100)
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+if addr == nil then
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+ print("No more addresses.")
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+else
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+ print(addr:byte(1,8))
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+ crc = ow.crc8(string.sub(addr,1,7))
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+ if crc == addr:byte(8) then
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+ if (addr:byte(1) == 0x10) or (addr:byte(1) == 0x28) then
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+ print("Device is a DS18S20 family device.")
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+ repeat
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+ ow.reset(pin)
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+ ow.select(pin, addr)
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+ ow.write(pin, 0x44, 1)
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+ tmr.delay(1000000)
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+ present = ow.reset(pin)
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+ ow.select(pin, addr)
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+ ow.write(pin,0xBE,1)
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+ print("P="..present)
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+ data = nil
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+ data = string.char(ow.read(pin))
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+ for i = 1, 8 do
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+ data = data .. string.char(ow.read(pin))
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+ end
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+ print(data:byte(1,9))
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+ crc = ow.crc8(string.sub(data,1,8))
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+ print("CRC="..crc)
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+ if crc == data:byte(9) then
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+ t = (data:byte(1) + data:byte(2) * 256) * 625
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+ t1 = t / 10000
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+ t2 = t % 10000
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+ print("Temperature="..t1.."."..t2.."Centigrade")
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+ end
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+ tmr.wdclr()
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+ until false
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+ else
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+ print("Device family is not recognized.")
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+ end
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+ else
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+ print("CRC is not valid!")
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+ end
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+end
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+```
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+
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+####See also
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+[ow.reset()](#owreset)
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+
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+## ow.setup()
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+Set a pin in onewire mode.
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+
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+#### Syntax
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+`ow.setup(pin)`
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+
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+#### Parameters
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+`pin` 1~12, IO index
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+
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+#### Returns
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+`nil`
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+
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+## ow.reset()
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+Perform a 1-Wire reset cycle.
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+
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+#### Syntax
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+`ow.reset(pin)`
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+
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+#### Parameters
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+`pin` 1~12, IO index
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+
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+#### Returns
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+ - `1` if a device responds with a presence pulse.
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+ - `0` if there is no device or the bus is shorted or otherwise held low for more than 250 µS.
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+
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+## ow.skip()
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+Issue a 1-Wire rom skip command, to address all on bus.
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+
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+#### Syntax
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+`ow.skip(pin)`
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+
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+#### Parameters
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+`pin` 1~12, IO index
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+
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+#### Returns
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+`nil`
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+
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+## ow.target_search()
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+Set up the search to find the device type `family_code` on the next call to `ow.search()` if it is present.
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+
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+#### Syntax
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+`ow.target_search(pin, family_code)`
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+
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+#### Parameters
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+ - `pin` 1~12, IO index
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+ - `family_code` byte for family code
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+
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+#### Returns
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+`nil`
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+
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+####See also
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+[ow.search()](#owsearch)
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+
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+## ow.write()
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+Write a byte. If `power` is 1 then the wire is held high at the end for parasitically powered devices. You are responsible for eventually depowering it by calling `ow.depower()` or doing another read or write.
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+
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+#### Syntax
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+`ow.write(pin, v, power)`
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+
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+#### Parameters
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+ - `pin` 1~12, IO index
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+ - `v` byte to be written to salve device
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+ - `power` 1 for wire being held high for parasitically powered devices
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+
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+#### Returns
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+`nil`
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+
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+####See also
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+[ow.depower()](#owdepower)
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+
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+## ow.write_bytes()
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+Write multi bytes. If `power` is 1 then the wire is held high at the end for parasitically powered devices. You are responsible for eventually depowering it by calling `ow.depower()` or doing another read or write.
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+
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+#### Syntax
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+`ow.write_bytes(pin, buf, power)`
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+
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+#### Parameters
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+ - `pin` 1~12, IO index
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+ - `buf` string to be written to slave device
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+ - `power` 1 for wire being held high for parasitically powered devices
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+
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+#### Returns
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+`nil`
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+
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+####See also
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+[ow.depower()](#owdepower)
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