Ascii file source, read binary value in file
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Hi,
I would like to read a file (on a linux filesystem) using the ASCII file data source. The file simply contains either a 0 or a 1 depending on a condition. No other characters or data are present in the file.
I can't figure out how to get the ASCII file data source to read this. It is looking at the correct file but I am not sure about what I should put in the additional settings for point identifier, value index etc. Any hints?
Cheers
Jeremy -
Oops, I meant to post this in 'User help', although this is somewhat hardware related as I am trying to access the GPIO pins on a Raspberry Pi (if successful I will post the steps here/on the wiki for others).
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Well, after playing around with this - I (mostly) have a solution using python, but it's pretty ugly and inefficient.
I would really like it if I could read the bit directly into mango as above.Again, the file just contains a single bit; a zero or a one, which changes as the input changes.
@phildunlap, perhaps you have some idea about how to do this? -
Also looking to implement similar data points for GPIO.
I have resorted to a "grep" and using the filename as a point identifier, which is ugly in itself, but the real problem is getting the binary data ("1" or "0") to be properly read into the regex. What I seem to be getting is a 1 if the regex matches, not the actual value of the regex pattern. Are there any examples for regex patters for binary data such as the GPIO values?
Thanks in advance.
Aldo
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This post is deleted! -
Hey guys, sorry I never saw this... I took a bit of a hiatus.
Yes you can do this with the ASCII file data source. Simply point the datasource at the file, configure a data point as follows:
Point Identifier:
Point Identifier Index: 2
Value Index: 1
Value Regex: (0|1)()So the trick here is to leave the point identifier totally empty and then capture an empty group at some point in our regex.
