DS1822,1920 1 wire thermometer
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Posts: 46,084
I am relatively new to the basic stamp, and i have successfully been
able talk to my ds1822 dallas 1 wire thermometer, however they come
default for 12 bit, which is a slow conversion, I have tried several
different sequences to write to the configuration register of the
sensor to change it to 9 bit resolution which would be a faster
conversion, I am using a BS2P24 and the OWOUT command, from what i
understand by reading dallas docs that after i send the write
scratchpad command my pointer is set at location 2, 0 and 1 are read
only, and that I should be able to just send binary 00 to it for
resolution change, if anyone has a sample command that successfully
initializes the write scratchpad and then sends data to the config
registers, would be greatly appreciated.
-christopher
able talk to my ds1822 dallas 1 wire thermometer, however they come
default for 12 bit, which is a slow conversion, I have tried several
different sequences to write to the configuration register of the
sensor to change it to 9 bit resolution which would be a faster
conversion, I am using a BS2P24 and the OWOUT command, from what i
understand by reading dallas docs that after i send the write
scratchpad command my pointer is set at location 2, 0 and 1 are read
only, and that I should be able to just send binary 00 to it for
resolution change, if anyone has a sample command that successfully
initializes the write scratchpad and then sends data to the config
registers, would be greatly appreciated.
-christopher
Comments
Make sure you are using the correct mode for OWOUT.
mode 1 resets the bus then sends data a byte at a time.
mode 2 sends data a byte at a time THEN resets the bus.
'reset bus then send skip rom
OWOUT OWpin, 1, [noparse][[/noparse]$CC]
'send write scratchpad command and 3 bytes of data then reset the bus
OWOUT OWpin, 2, [noparse][[/noparse]$4E, $00, $00, $00]
Chuck Chargin Jr.
At 06:46 PM 9/30/2003 +0000, you wrote:
>I am relatively new to the basic stamp, and i have successfully been
>able talk to my ds1822 dallas 1 wire thermometer, however they come
>default for 12 bit, which is a slow conversion, I have tried several
>different sequences to write to the configuration register of the
>sensor to change it to 9 bit resolution which would be a faster
>conversion, I am using a BS2P24 and the OWOUT command, from what i
>understand by reading dallas docs that after i send the write
>scratchpad command my pointer is set at location 2, 0 and 1 are read
>only, and that I should be able to just send binary 00 to it for
>resolution change, if anyone has a sample command that successfully
>initializes the write scratchpad and then sends data to the config
>registers, would be greatly appreciated.
>-christopher
>
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