PyRealTime Plot is a Python based tool that leverages the QT framework to plot data
in real time. It is fully configurable by the user in terms of the data source for
plots and which plots are on and plotting data. The data can be sent in packets of
any length and plotted on any one of the 255 user-definable plot types.
This project is developed for Python 2.7 (x64). It requires the following
dependencies to run:
- numpy
- pyqtgraph
- PyQt5
In order to open up the GUI, simply run the command 'python main.py'.
The GUI is meant to be flexible and allow the user to configure the plots available
via the file config.json. The configuration file allows the user to specify the types
of plots that are available, the properties of each plot and the data source for the
plots. Each plot described in the config file can be added or removed at runtime and
has a data type. The data type is the a unique identifier that is used to determine,
which numbers from the data source are to go to each plot. Check the config.example
file for more details on how each plot and data source can be configured.
In order to start plotting data, the data sent via the data source must adhere to a
certain format. The data sent via the data source is expected to be any number of 4
byte floats accompanied by one byte indicating the data type, and an 8 byte stop
signal, which is the float binary representation of NaN sent indicating the end of a
packet. The number of bytes in the payload of the packet (every byte except for the
8 byte stop signal) must be a multiple of 5 as the payload is made up of 4 byte floats
and their 1 byte data types. The displayed plots are updated each time a packet is
received. Each float should be sent least significant byte first. In the following
example, the bytes are transmitted from left to right.
Float transmission format example:
0xTT 0xNN 0xNN 0xNN 0xNN
0xTT => byte corresponding to the data type
0xNN => byte corresponding to the float representation of the transmitted number
In order to send the number -0.0027 with data type 0x00, the transmission would be:
0x00 0x7c 0xf2 0x30 0xbb
-0.0027 is stored as 0xbb30f27c, so notice that the float is transmitted with the
least significant byte FIRST.
After sending the floats and their data types, two NaNs must be sent to signal that
the end of the packet has been reached and the plots should be updated:
NaN transmission:
0xff 0xff 0xff 0x7f 0xff 0xff 0xff 0x7f
Here's what transmitting -0.0027 with data type 0x00 and -0.0433 with data type
0x01 in the same packet would look like:
0x00 0x7c 0xf2 0x30 0xbb 0x01 0x57 0x5b 0x31 0xbd 0xff 0xff 0xff 0x7f 0xff 0xff 0xff 0x7f
- Fork it!
- Create your feature branch:
git checkout -b my-new-feature - Commit your changes:
git commit -am 'Add some feature' - Push to the branch:
git push origin my-new-feature - Submit a pull request :D
This tool was originally developed in order to plot data coming from a
microcontroller over a serial port. Specifically, it was developed to plot IMU
sensor data in real time to analyze noise that was caused by motor vibrations on
a drone. Even though it was made with that purpose in mind, it was designed to
general enough that it can plot any sequence of floats coming from a file or from
a serial port.
- Different data sources for each plot
- Socket based data source
- Different y-axis types (i.e. log)