@@ -13,10 +15,10 @@ Compute the 1-Wire CRC16 and compare it against the received CRC.
...
@@ -13,10 +15,10 @@ Compute the 1-Wire CRC16 and compare it against the received CRC.
-`crc` CRC starting value (optional)
-`crc` CRC starting value (optional)
#### Returns
#### Returns
`bool`true, if the CRC matches; false for mismatch.
true if the CRC matches, false otherwise
## ow.crc16()
## ow.crc16()
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:
Computes 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:
1. The CRC is transmitted bitwise inverted.
1. The CRC is transmitted bitwise inverted.
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.
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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@@ -25,98 +27,98 @@ Compute a Dallas Semiconductor 16 bit CRC. This is required to check the integr
...
@@ -25,98 +27,98 @@ Compute a Dallas Semiconductor 16 bit CRC. This is required to check the integr
`ow.crc16(buf[, crc])`
`ow.crc16(buf[, crc])`
#### Parameters
#### Parameters
-`buf` string value, data to be calculated check sum in string.
-`buf` string value, data to be calculated check sum in string
-`crc` CRC starting value (optional)
-`crc` CRC starting value (optional)
#### Returns
#### Returns
`crc16`the CRC16, as defined by Dallas Semiconductor.
the CRC16 as defined by Dallas Semiconductor
## ow.crc8()
## ow.crc8()
Compute a Dallas Semiconductor 8 bit CRC, these are used in the ROM and scratchpad registers.
Computes a Dallas Semiconductor 8 bit CRC, these are used in the ROM and scratchpad registers.
#### Syntax
#### Syntax
`ow.crc8(buf)`
`ow.crc8(buf)`
#### Parameters
#### Parameters
`buf` string value, data to be calculated check sum in string.
`buf` string value, data to be calculated check sum in string
#### Returns
#### Returns
CRC result as byte.
CRC result as byte
## ow.depower()
## ow.depower()
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.
Stops 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.
#### Syntax
#### Syntax
`ow.depower(pin)`
`ow.depower(pin)`
#### Parameters
#### Parameters
`pin` 1~12, IO index
`pin` 1~12, I/O index
#### Returns
#### Returns
`nil`
`nil`
####See also
####See also
-[ow.write()](#owwrite)
-[ow.write()](#owwrite)
-[ow.write_bytes()](#owwrite_bytes)
-[ow.write_bytes()](#owwrite_bytes)
## ow.read()
## ow.read()
Read a byte.
Reads a byte.
####Syntax
####Syntax
`ow.read(pin)`
`ow.read(pin)`
#### Parameters
#### Parameters
`pin` 1~12, IO index
`pin` 1~12, I/O index
#### Returns
#### Returns
Byte read from slave device.
byte read from slave device
## ow.read_bytes()
## ow.read_bytes()
Read multi bytes.
Reads multi bytes.
#### Syntax
#### Syntax
`ow.read_bytes(pin, size)`
`ow.read_bytes(pin, size)`
#### Parameters
#### Parameters
-`pin` 1~12, IO index
-`pin` 1~12, I/O index
-`size` number of bytes to be read from slave device
-`size` number of bytes to be read from slave device
#### Returns
#### Returns
`string` bytes read from slave device
`string` bytes read from slave device
## ow.reset()
## ow.reset()
Perform a 1-Wire reset cycle.
Performs a 1-Wire reset cycle.
#### Syntax
#### Syntax
`ow.reset(pin)`
`ow.reset(pin)`
#### Parameters
#### Parameters
`pin` 1~12, IO index
`pin` 1~12, I/O index
#### Returns
#### Returns
-`1` if a device responds with a presence pulse.
-`1` if a device responds with a presence pulse
-`0` if there is no device or the bus is shorted or otherwise held low for more than 250 µS.
-`0` if there is no device or the bus is shorted or otherwise held low for more than 250 µS
## ow.reset_search()
## ow.reset_search()
Clear the search state so that it will start from the beginning again.
Clears the search state so that it will start from the beginning again.
#### Syntax
#### Syntax
`ow.reset_search(pin)`
`ow.reset_search(pin)`
#### Parameters
#### Parameters
`pin` 1~12, IO index
`pin` 1~12, I/O index
#### Returns
#### Returns
`nil`
`nil`
## ow.search()
## ow.search()
Look for the next device.
Looks for the next device.
#### Syntax
#### Syntax
`ow.search(pin)`
`ow.search(pin)`
#### Parameters
#### Parameters
`pin` 1~12, IO index
`pin` 1~12, I/O index
#### Returns
#### Returns
`rom_code` string with length of 8 upon success. It contains the rom code of slave device. Returns `nil` if search was unsuccessful.
`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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@@ -125,14 +127,14 @@ Look for the next device.
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@@ -125,14 +127,14 @@ Look for the next device.
[ow.target_search()](#owtargetsearch)
[ow.target_search()](#owtargetsearch)
## ow.select()
## ow.select()
Issue a 1-Wire rom select command. Make sure you do the `ow.reset(pin)` first.
Issues a 1-Wire rom select command. Make sure you do the `ow.reset(pin)` first.
#### Syntax
#### Syntax
`ow.select(pin, rom)`
`ow.select(pin, rom)`
#### Parameters
#### Parameters
-`pin` 1~12, IO index
-`pin` 1~12, I/O index
-`rom` string value, len 8, rom code of the salve device
-`rom` string value, len 8, rom code of the salve device
#### Returns
#### Returns
`nil`
`nil`
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@@ -195,38 +197,38 @@ end
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@@ -195,38 +197,38 @@ end
[ow.reset()](#owreset)
[ow.reset()](#owreset)
## ow.setup()
## ow.setup()
Set a pin in onewire mode.
Sets a pin in onewire mode.
#### Syntax
#### Syntax
`ow.setup(pin)`
`ow.setup(pin)`
#### Parameters
#### Parameters
`pin` 1~12, IO index
`pin` 1~12, I/O index
#### Returns
#### Returns
`nil`
`nil`
## ow.skip()
## ow.skip()
Issue a 1-Wire rom skip command, to address all on bus.
Issues a 1-Wire rom skip command, to address all on bus.
#### Syntax
#### Syntax
`ow.skip(pin)`
`ow.skip(pin)`
#### Parameters
#### Parameters
`pin` 1~12, IO index
`pin` 1~12, I/O index
#### Returns
#### Returns
`nil`
`nil`
## ow.target_search()
## ow.target_search()
Set up the search to find the device type `family_code`. The search itself has to be initiated with a subsequent call to `ow.search()`.
Sets up the search to find the device type `family_code`. The search itself has to be initiated with a subsequent call to `ow.search()`.
#### Syntax
#### Syntax
`ow.target_search(pin, family_code)`
`ow.target_search(pin, family_code)`
#### Parameters
#### Parameters
-`pin` 1~12, IO index
-`pin` 1~12, I/O index
-`family_code` byte for family code
-`family_code` byte for family code
#### Returns
#### Returns
`nil`
`nil`
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@@ -235,15 +237,15 @@ Set up the search to find the device type `family_code`. The search itself has t
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@@ -235,15 +237,15 @@ Set up the search to find the device type `family_code`. The search itself has t
[ow.search()](#owsearch)
[ow.search()](#owsearch)
## ow.write()
## ow.write()
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.
Writes 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.
#### Syntax
#### Syntax
`ow.write(pin, v, power)`
`ow.write(pin, v, power)`
#### Parameters
#### Parameters
-`pin` 1~12, IO index
-`pin` 1~12, I/O index
-`v` byte to be written to salve device
-`v` byte to be written to salve device
-`power` 1 for wire being held high for parasitically powered devices
-`power` 1 for wire being held high for parasitically powered devices
#### Returns
#### Returns
`nil`
`nil`
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@@ -252,15 +254,15 @@ Write a byte. If `power` is 1 then the wire is held high at the end for parasiti
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@@ -252,15 +254,15 @@ Write a byte. If `power` is 1 then the wire is held high at the end for parasiti
[ow.depower()](#owdepower)
[ow.depower()](#owdepower)
## ow.write_bytes()
## ow.write_bytes()
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.
Writes 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.
#### Syntax
#### Syntax
`ow.write_bytes(pin, buf, power)`
`ow.write_bytes(pin, buf, power)`
#### Parameters
#### Parameters
-`pin` 1~12, IO index
-`pin` 1~12, IO index
-`buf` string to be written to slave device
-`buf` string to be written to slave device
-`power` 1 for wire being held high for parasitically powered devices
-`power` 1 for wire being held high for parasitically powered devices