muxrplot

Logging and plotting the voltnut way

This is the example output of mplot. Data was captured with mplotlogger. Both scripts are part of this project. The device polled was Keithley 2015 via USB Serial rs232. But you should be able to make it work with any device with minor tweaks.

Clone the repo

git clone git@github.com:sirmo/muxrplot.git
cd muxrplot

Setup a virtualenv (optional)

Virtualenv lets you install all the prerequisites for this program in the repo directory itself. This way you don't have to modify anything on your system. To initialize virtualenv, do the following:

virtualenv env
source env/bin/activate

By the way you will have to run the activate command every time you want to run mplot with a new session. Once activated you will usually see a (env) in your prompt.

Install

To install mplot on your system:

make install

Once installed you can run.

> mplotlogger -h
usage: mplotlogger [-h] [-d DEVICE] [-i INTERVAL] [outfile]

positional arguments:
  outfile

optional arguments:
  -h, --help            show this help message and exit
  -d DEVICE, --device DEVICE
                        Path to the serial device
  -i INTERVAL, --interval INTERVAL
                        Polling interval

and:

> mplot -h
mplot
usage: mplot [-h] [-t TITLE] [-y YDIGITS] [infile] [outfile]

positional arguments:
  infile
  outfile

optional arguments:
  -h, --help            show this help message and exit
  -t TITLE, --title TITLE
                        title to be used in the chart

Example Usage

Suppose you have a Keithley 2000, 2001 or similar connected to /dev/cu.usbserial

> mplotlogger -d /dev/cu.usbserial target/my_first_capture
logging to: target/my_first_capture
|

If you check directory target (provided you've made one) and file my_first_capture you should see a comma delimited file which contains the captured data.

> head target/my_first_capture
timestamp;value
1496033039.2;9.9999562
1496033040.2;9.99995613
1496033041.2;9.99997087
1496033042.21;9.99996245
1496033043.21;9.9999628
1496033044.21;9.99996742
1496033045.21;9.99997018
1496033046.22;9.99995482
1496033047.22;9.99996508

To plot this data you invoke the mplot:

> mplot target/my_first_capture
mplot
target/my_first_capture (29-May-2017)
max: 9.99997749
min: 9.99994525
p-p: 0.00003224
o: 6.782e-06
samples: 137
duration: 0d 00:02.16
mean: 9.99995736

The end result, will be a .png file target/my_first_capture.png:

Install issues

If you run into install issues during make install try using pip separately, and make sure numpy and scipy are installed properly. For some reason these two seem to give me most problems.

pip install scipy
pip install numpy