RoadTest: Picoscope 2205A Oscilloscope
Evaluation Type: Independent Products
Did you receive all parts the manufacturer stated would be included in the package?: True
What other parts do you consider comparable to this product?: Hantek 6022BE usb oscilloscope 20MHz / UNI-T UTD2025C benchtop 25MHz.
What were the biggest problems encountered?: Could not load the captured *.csv file for importing into AWG.
At first I would like to thank Pico Technology Ltd and Element 14 for this wonderful opportunity to review a smart device like PICOScope 2205A.
PicoScope 2205A overview:
Its not kind of a high spec equipment but a handy tool for those who need a “scope” anywhere anytime. Its small enough to fit in your pocket but strong enough to provide a bench-top performance and smart enough to give you flexible operations. In a single word, it just a ‘perfect’ entry level PC based Oscilloscope.
Number of channel - 02
Bandwidth - 25 MHz
Sampling rate (max) - 200MS/sec for single channel and 100MS/sec for double channel
Vertical resolution - 8 bits
Buffer size - 16k
AWG bandwidth - 100 kHz
Input range - +/- 20Vpk max
What does make it special?
Ok, I have to admit that there is not much specialty in the oscilloscope. But what makes it unique is the flexible operations and the ultimate freedom of processing data using the PC software…. ‘sky is the limit’.
It can be used as a ‘spectrum analyzer’ or ‘high speed data acquisition interface’.
Data storage in different formats and programmable APIs give unlimited opportunity for interfacing it with other softwares and offline signal processing.
And obviously its portability gives benefit over a bench-top scope.
What’s in the box?
Picoscope 2205A contains –
simplest setup one can afford for general purpose testing equipments.
Basic signal test:
Probes are connected but left open without any input signal to get the 50Hz effect.
Case01 – my laptop is running on battery
Scope view and spectrum view – 20mV pk2pk noise
Case 02 – laptop is connected to the mains power
However its due to the absence of earth connection. An external earth connection keeps the 50Hz noise low.
Working with sinusoidal waves –
Taking a 10Khz sinusoidal wave with 500kS/sec
Scope view Spectrum view
Signal becomes a little bit noisy as usual if I plug the laptop in the mains lines. Persistence mode can give a better view.
The sampling rate can be changed by the user. But the toolbar shows approximate number of samples, the minimum that would be representing on the window. Actual sampling rates are selected automatically which can be viewed by selecting the signal properties.
I tried to view the sinusoidal signal at around 100kS/sec and found the following output.
For 1:1 attenuation it has a bandwidth of 15MHz. Input resistance 1Mohms and capacitance 46pF.
For 10:1 attenuation it has a bandwidth of 60MHz. input resistance 10Mohms and capacitance 15pF.
Highlighted features of PicScope6:
Data storage formats -
It's possible to store both current waveform on the window and the full buffer as slides.
Channel options –
Different Probe types can be selected from 'Channel Option'
Resolution is usually of 8bit --> 256 steps where it can be increased up to 12bits. This enhancement actually features a moving average filter.
Resolution enhancement causes the noisy spikes over the sinusoidal signal be flattened and widened as it acts like a low-pass filter.
Buffer overview –
Previous buffered waveforms can be browsed and searched through this window.
Spectrum view –
PicoScope introduces some basic but effective features over its spectrum analyzer.
Spectrum bins – it has a huge buffer length comparing with the bench-top scopes like UTD2025C 25MHz. So number of frequency bins is large to divide the spectrum into more steps. But at the same time it takes much time to generate the spectrum view for longer bins.
For 50 kHz sin wave with spectrum bins = 16384 & Window Function --> Blackman : PicoScopes clearly generates far better spectrum view but much slower than UTD2025C bench-top
Window functions – Display modes - Range -
Persistence mode -
PicoScope can keep the track of the old waveforms in persistence mode where new waveforms are superimposed with bright colors on the old waveforms in faded colors. Along the intensity of color, persistence mode uses different colors for different frequency components.
Advanced Trigger -
Picoscope has advanced trigger which can be configured by the user for analyzing different forms of wave shapes like analog signal following a window, level dropout after a pusle train, interval between two successive edges, detecting pulses of same width etc.
Tools – 'Tools' menu provides some features like Basic Math Functions, working with Custom Probes, Alarm generation on the activity of a particular event, Masking an input signal with offset values, racoring Macro for repetitive task, Serial Decoding of CAN, I2C, SPI, and UART protocol and AWG – the arbitrary waveform generator.
MATH FUNCTION MASK
Another interesting feature of PicoScope is the capability of generating various general purpose signals with a good range of frequency and amplitude.
Sweep modes can be a useful tool to emulate a frequency response of a system.
Bandwidth of the signal generator is 100 kHz and amplitude is +/- 2 Vpk.
The Arbitrary Waveform Generator [AWG] is a useful tool to generate a waveshape from the previously loaded data of an input channel. Also it supports *.csv files to load a sequence of data to form a waveshape.
Unfortunately I could not load *.csv files to AWG which was captured from an input channel. I’ll take a deeper look on the length of data stream later on, hopefully it can be figured out.
At higher frequency generated waveform looses its shape.
5 kHz Square wave by signal generator 100 kHz Square wave by signal generator
Working with Bio-signal:
I have tested the ECG trainer kit developed by our Department of Biomedical Physics and Technology, University of Dhaka with PicoScope. I have found it very interesting as the ECG signal [LEAD1] was pretty clean without any sort of shielding over the hardware. Generally the bench-top oscilloscope gives much noise [mostly 50Hz]. But this time I have connected the PicoScope with the desktop PC which was directly powered by the mains AC and still PicoScope managed to produce a comparatively clean signal. However, I have to use the on board opto-isolator of the trainer kit. Most importantly, the spectrum view is kind of amazing - because it helps me to find out the characteristics of the signal and noise apart. Also it gives the opportunity to store data, import it to elsewhere and implement further signal processing like digital filters.
And yes, I have to admit that this tool is very effective for analyzing bio-signals, specially when a portable solution is needed.
ECG Trainer Kit My ECG on PicoScope6 [Lead1 combination]
Hi Kamrul, thanks very much for your detailed review of the PicoScope 2205A oscilloscope; we appreciated the time and effort you put into it. I'm not sure why the CSV file import to the waveform generator didn't work - if you give our support team a call I'm sure they can solve it for you. Their details are on the Pico website www.picotech.com
Thanks again for your review, we enjoyed reading it.
Business Development Manager
Pico Technology Ltd.
I had not taken a deep look at this product, but I can see some very interesting possibilities now that I have seen it in operation.