Using the FlexSEA GUI

Important: we are currently working hard on adding functionality to the GUI. A major code reorganization is planned (to have a cleaner, more object oriented project) for the coming weeks. Any GUI documentation or screenshot will be outdated by the end of today… This post contains only a few tips and tricks.

Getting started, launching the program:

  • We do not have an installer for the GUI; you have to compile it from the sources. All the details are in Installing the FlexSEA GUI Development Tools. All of the info below assumes you are using Linux.
  • Open a terminal and navigate to your build/release directory (in my case it’s ../FlexSEA-Git-Exp/FlexSEA/execute-gui-1/build/). You should see ‘execute-gui-1’.
  • To avoid COM port permissions issues we launch the program in root mode: sudo ./execute-gui-1. Keep the terminal open and visible, it will display useful information.
  • You should now see the config tab:


Connect your board:

  • Connect a FlexSEA board to your computer via USB. If you are using a VM, make sure that it sees your device. dmesg -T should list it. Note the COM port (typically ttyACM0). Example:
  • dmesg
  • Make sure that the right COM port and Slave are selected. Click Open COM and wait for ‘Success’
  • At this point you are ready to use the GUI. Explore the different tabs!

When it doesn’t work… and other pieces of advice:

  • In the current software version the PSoC only tries to connect to USB at boot. It’s easier to get it to properly work with your VM if you are in it when you connect the USB cable.
  • Always keep the terminal open to see what’s happening.
  • If you can’t connect, or you keep getting “No bytes”: 1) Make sure that you selected the right slave, 2) Make sure that you are using the same software version on the two devices and 3) power cycle (turn off battery power, disconnect and re-connect USB).
  • Sometimes it takes a few seconds for Stream to start. Monitor the terminal window; if you see at least one “48 bytes read” be patient and it’ll start working.
  • The Plot window refreshes at 35Hz. Keep that in mind while analyzing signals.
  • Always close the GUI before disconnecting USB.

Example #1: read Execute’s sensors:

  • Connect Execute to your Linux computer via USB. No battery power at this time.
  • Launch the GUI (sudo ./execute-gui-1)
  • Open the COM port. Make sure it says ‘Success’
  • Click on the Execute tab and click on Stream ON. You should see values refreshing. Execute’s RGB LED should also be steady Green.


  • Apply battery power if needed (please note that many analog readings are wrong on USB power, as we are not getting exactly 5V)
  • You can plot variables in the Plot tab.