1. VPN
vpn.rc.fas.harvard.edu
...
ssh pi@10.245.20.16
lisefasrc-bang
cd lisemagnetto
/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...
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
| device | oldest | newest | notes |
|---|---|---|---|
| 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 |
| 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 |
| RPIR6 | Dec 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 |
| RPIR7 | Nov 30 | Dec 16 | working OK |
| RPIR8 | Nov 30 | Dec 15 | working OK |
| RPIR9 | Nov 30 | Dec 16 | working OK |
| RPIR10 | ssh: connect to host 10.245.20.18 port 22: Network is unreachable | ||
| RPIR11 | Nov 29 | Dec 15 | working OK |
| RPIR12 | Nov 29 | Dec 16 | working 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?