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Magnetometer access and analysis

Magnetometer access and analysis

Owned by Christopher Stubbs
Last updated: Dec 17, 2022

1. VPN

vpn.rc.fas.harvard.edu 

stubbs@fasrc

Google authenticator code for FASRC


2. login

ssh stubbs@login.rc.fas.harvard.edu

cat4FARC!

google authenticator code. 

ssh stubbs@graph01.rc.fas.harvard.edu

raspberry PI direct access by 

ssh pi@10.245.20.16

lisefasrc-bang


cd to
/home/pi/Desktop/lise_magnet/data


there are individual circular buffer data files, timestamp is seconds after Unix epoch. Need a converter for that: for OSX:

date -r 123439819723 '+%m/%d/%Y:%H:%M:%S'

then 3 axes of B field data

3. data access


mapping of IP to physics locations at

https://hu.sharepoint.com/:x:/r/sites/DeanofScience/_layouts/15/Doc.aspx?sourcedoc=%7BE9F63980-D467-46BB-8C05-E9624622F0F7%7D&file=List%20of%20RPi%20Devices.xlsx&action=default&mobileredirect=true


getting from Unix epoch to date on R Pi machines: 

pi@raspberrypi:~/Desktop/lise_magnet/data $ head -1 data.out.5

1669345229,34174,31034,30232

pi@raspberrypi:~/Desktop/lise_magnet/data $ date --date="@1669345229"

data xfer: 

scp pi@10.245.20.23:~/Desktop/lise_magnet/data/data* . 
but beware duplicate file names! 


Status on Dec 16 2022

deviceoldestnewestnotes
RIPIR1

Mon 21 Nov 2022 02:48:59 PM EST

Tue 13 Dec 2022 01:11:58 PM EST

data collection died on Dec 13
2022-12-13-13-11-18 socket write successfull
2022-12-13-13-11-48 socket write successfull
2022-12-13-14-46-19 Error: Arduino serial port is idle.
2022-12-13-16-20-40 Error: Arduino serial port is idle.
2022-12-13-17-55-01 Error: Arduino serial port is idle.

RPIR2

ssh: connect to host 10.245.20.26 port 22: Network is unreachable

RPIR3

ssh: connect to host 10.245.20.25 port 22: Network is unreachable

PRIR4

Thu 24 Nov 2022 10:00:29 PM EST

Fri 16 Dec 2022 09:09:15 PM EST

this one seems to be working. 
RPIR5

Fri 25 Nov 2022 12:04:35 PM EST

Fri 16 Dec 2022 09:18:51 PM EST

also working
RPIR6Dec 15

Fri 16 Dec 2022 09:31:44 PM EST

also working, but taking data at 1 Hz not 1/10 Hz. . Only a few days of data stored
RPIR7Nov 30 Dec 16 working OK
RPIR8Nov 30 Dec 15working OK
RPIR9Nov 30 Dec 16working OK
RPIR10

ssh: connect to host 10.245.20.18 port 22: Network is unreachable

RPIR11Nov 29 Dec 15

working OK

RPIR12Nov 29Dec 16working OK


data storage estimate. 

3 axes plus timestamp, over around 3 weeks, requires 5.3M

empty disk space is around 27G

So we could store 4500 times as much data. That's enough for two centuries. 



Tool for conversion of JSON to CSV files: dasel on MAC. brew install dasel

$ dasel -r json -w csv < sample.json 
color,id,value
red,1,#f00
green,2,#0f0
blue,3,#00f

Nope, didn't work. Evidently json2tsv works better?

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