Manual data logging and analysis
Guide to manual data viewing with Ardono IDE ‘Serial Plotter’

Install Arduino IDE software on you computer/device, see here for guide.

Install Arduino sketch V10 on Ardiono UNO processor, click here to download.

Check you have Arduino board correctly connected by clicking on: ‘Tool’ and then ‘Port’ see example below:

Please note, you may be a different port number (i.e. not COM18) depending on your computer/device setup

Then click on: ‘Tool’ and then ‘Serial Plotter’ see example below:

The displayed signal with vary if crocodile clips open or closed circuit, see example below:


If you have a signal source available such as signal generator you can set to LOW voltage (say 0.1 Volts) and low frequency (say 0.1 Hz).

CAUTION! Don’t connect the PhyLink electronics to more than 2 Volt or the Analogue to Digital converter (ADS1118) could be damaged


To minimize electrical noise use the green lead (with plug & crocodile clip) to connect ground/negative of Arduino board to ground of signal generator as shown below:


Make a note of the number of the communication port (for example, Com 1, Com 2 …) allocated to PhyLink by looking under ‘Tools’ then ‘Port’ on Arduino IDE.
Guide to manual data analysis with ‘CoolTerm’ and ‘Sigview’



CoolTerm is a simple (freeware) serial port terminal program which can record data (voltage measurements) sent from PhyLink to your computer/device.


Roger Meier’s CoolTerm data logger software can be downloaded from


Close Arduino IDE (and Serial Plotter) as this may block CoolTerm from working correctly.


After installing CoolTerm select ‘Connection’ then ‘Options’ as shown below:

Then under the ‘Options’ menu select ‘Port’ and click the ‘down arrow’ to show list of communication ports (Com 1, Com 5, COM 12 …) the numbers will be different on each computer. Select the port being used to communicate with PhyLink, see below:

If you are unsure which Port number PhySense is using look under ‘Tools’ then ‘Port’ with Arduino IDE then close Arduino IDE

Select ‘Connection’ then ‘Options’ then drop down menu under ‘Baudrate’ as shown below:
The default baud rate is 9600. To improve performance PhyLink is usually set to 1200.
Select ‘Connection’ then ‘Connect’ as shown below:
The voltage measurements should appear as a long column of (changing) numbers, see below.
If the numbers are all zero trying touching an input wire with your finger to see if they change. If they don’t change or you don’t see any numbers something has gone wrong and you’ll need to check settings.
Select ‘Connection’ then ‘Capture to Textfile’ then ‘Start’ as shown below:


Choose file name for text file (*.txt) and folder to save in, as shown in example below:


When you want to stop saving measurements to text file select ‘Connection’ then ‘Capture to Textfile’ then ‘Stop’ (or Pause) as shown below:



The saved text file with contain the data (voltage measurements) which can be plotted and analysed. You can open/view the data with Notepad or Word, see example below:


The data should be a long column of numbers which change. If the numbers are all zero or don’t change something has gone wrong and you’ll need to repeat measurement .


Example data file recorded with PhyLink below.


Waveform: Sine wave

Frequency: 0.1Hz (100 mHz)

Amplitude: 0.1V (100 mV)

Arduino sketch: V10

Voltage range: ± 2.048 V

Sample rate: 128 samples per second (SPS)


If you want to record multiple channels click here to see guide



Sigview is a real-time and offline signal analysis program with wide range of powerful signal analysis tools including Fast Fourier Transform (FFT). SigView is shareware software which can be downloaded from (and used for free for 21 days) from:

You could use an alternative FFT program for the following signal analysis


Install and start SigView. From the SigView menu, select ‘File’ then ‘ASCII files’ then ‘Import signal (decimal comma)..’ see example below:


Then select and ‘Open’ the saved data (*.txt) file, see example below:


Enter the sample rate. In our example, 128 samples per second. Then click ‘OK’ see example below:


All the data will be displayed in a window, see example below:


To see the data more clearly, select ‘Edit’ then select ‘ Extract signal part (from-to)” then enter from ‘0’ to the max value of range interested. In the example below we’ve zoomed in to see 120 seconds.


Zoomed in view of waveform is then displayed, see example below:


Select ‘Signal tools’ then ‘FFT spectrum analysis’ see example below:


The data will be displayed in frequency spectrum, see example below:

To see the frequency spectrum more clearly, select ‘Edit’ then select ‘ Extract signal part (from-to)” then enter from ‘0’ to the max value of range interested, in our example 0.24Hz, see below:

Zoomed in view of frequency spectrum is then displayed, see example below:

In real measurements waveforms are distorted and harmonics appear


The fundamental frequency is 0.1 Hz which was the frequency set on the signal generator, see below:


Repeatedly measuring the fundamental frequency can be manually intensive so the PhyLink software aims to automate the process.