Developer info

This page is especially for those who like to develop new software for the HeartTuner, like games, biofeedback tools and special visualizations, Internet connectivity, statistical analyses, custom design measuring probes, etc. We have put the basic tools and info here on this page for you. Please study this first, before asking questions.


Connector wiring

The device allows for a signal for EKG to be measure with a grounding wire on both wrists. This has proven to be a good enough alternative to a grounding wire on the left leg.
The two electrodes each have a signal wire and a grounding wire. The grounding wires are internally connected to the ground of the device. The two signal wires are being measured differentially for each channel.


The HeartTunerPro software outputs two data files that con be used as input for various applications. Although there are possibly more elegant solutions to this, effectively a common text file that is updated regularly can be read by many applications without heavy losses on speeds and performance.

Both files are located in the program folder, usually C:\Program Files\HeartTuner01.

The Emotional Index and Amplitude data (EIdata.txt)

This file is updated every 1 second and contains four figures, the Emotional Index and the Amplitude for each channel. These figures are the result of calculating the Septrum data and checking for the highest peak in a limited interval.

Both the HeartWaves Valentine game as the Harmonic Module use this data.

The format is:


For programmers in Visual Basic, here is some sample code that demonstrates how this data could be read. We suggest to use a timer or check the file date to see when new data is available.

Sample code for reading EIdata.txt

The full Septrum data (log.SEP)

This file is updated every 4 seconds and contains the full Septrum Graph data point set. It contains 64 points for each channel. The file is being appended to every time new data is calculated and thus it gradually grows in size.

The format is:

000 value0 value1 value2 ... valueN<newline>
001 value0 value1 value2 ... valueN<newline>

The last pair in the file is the most recently written data. (Use a pointer to the end and search from there to get the data in quick.)

Some sample Visual Basic code to read the Septrum data.

FFT Analysis (log.FFT)

The FFT analysis of the raw data is filed cumulatively in the log.FFT file. The format is the same as the log.SEP file, although there are 128 data points on each channel.

Raw Data (log.txt)

This is the whole history of raw data. As the Septrum and FFT file, it is useful for post measurement statistical analysis and graphing. Yet it can also be used for life input response, because the data is update regularly. Just scan for the file to change and take the last portion of it to get access to the real-time raw data.

The format is:

23-9-2002 (date)
16:08:23 (time)
value(t=0)ch1 value(t=0)ch2
value(t=1)ch1 value(t=1)ch2
value(t=2)ch1 value(t=2)ch2
value(t=3)ch1 value(t=3)ch2
value(t=N)ch1 value(t=N)ch2

Download sample Visual Basic project.