When National Instruments developed its virtual instrumentation product, it created a new market and helped many design engineers to explore personal computer as a test and measurement platform. The availability of affordable PCs with every design engineer was market driver at that time to leverage PC/laptop as test and measurement platform with some less costing external data acquisition hardware and software. National Instruments thrived on that model and there are many other small companies offering USB DAQ which are called as USB/PC oscillo-scope.
But now with the most of the electronic design engineers having smart phone, it is just plain common sense of electronics engineer to have an option to use them as test and measurement display if not as platform. This has giving new direction to the development of virtual instrumentation.
The data acquisition hardware combined with a computing platform can now be developed in small form factor hardware of size less than credit card.
This concept has given birth to two interesting virtual instrumentation products now available in the market. They are smartscope from Lab-nation and the Red Pitaya. Good thing about these two products are, they are open source projects. Both are designed using Xilinx FPGAs. The signal frequency and amplitude of the virtual scope displayed on the mobile phone can be controlled through normal touch interface, so there are no knobs.
1. The SmartScope from Lab-nation:
The SmartScope is priced around US$ 200, a little less or more for different packages depending on the external support hardware peripheral you buy.
The SmartScope can be powered using USB cable from the smart phone or through external USB power source. Along with the availability of oscilloscope function, the SmartScope also provides the option to use this device as logic analyser and waveform generator.
The SmartScope supports multiple operating systems including Linux, IoS, android and Windows. But there are issues while you connect to each one of these. SmartScope will only be recognised in case you apply jailbreak patch to your IoS devices (iPhone and iPad). And in case of Android you got to check whether your phone supports USB- OTG. It looks most of the latest android phones doesn't have much of the issue. However we seriously suggest you to check further details at the website:
2. Red Pitaya
Though expensive Red Pitaya is more advanced which has taken care of some of the constraints you face with SmartScope. Although most of the oscilloscope related specifications matches with the SmartScope, Red Pitaya offers smart phone like apps which can be downloaded from a cloud for specific application. You can also develop your own app. Red Pitaya uses Xilinx Zynq FPGA whereas SmartScope uses Spartan FPGA from Xilinx. The use of advanced FPGA makes both the scope extremely reconfigurable. FPGA programmers can apply their skills in enhancing the performance of these devices.
Red Pitaya works like a web server, where it can be accessed from any Internet connected computer or smart phone by typing the IP address on a web browser. Red Pitaya can be connected to your network either using ethernet cable or Wi-Fi. Micro USB port is provided to power the unit and also to connect this device to another console. The Linux powered system comes with power supply, BNC connectors and probes. By having its own DHCP configuration, Red Pitaya can be easily set up. If you wish to set up manually, there is also option to do that. the SD memory card supplied with the unit is loaded with the software, otherwise if you have your own SD memory card, downloading the software into it is not difficult.
The apps presently available for you to download includes oscilloscope, signal generator, spectrum analyser, LCR meter and more. Downloading the apps is easy just like smart phone apps, you got to visit a cloud place called Bazaar from Red Pitaya to download apps.
The option of moving signal data from the MATLAB or getting the signal data into the MATLAB is also offered.
If you're a electronics DIY enthusiast/hobbyist or a student who would like to established your own lab on your desk, better you not invest into a costly oscilloscopes unless you require signal bandwidth above 50 MHz.
The cost of Red Pitaya is 200 US$ higher than Smartscope, which is around US$ 370-470.
The specification of Smart Scope:
Bandwidth: 45 MHz -3dB point
Sample rate: 2 × 100 MS/s
Max pre-trigger position: 16 × full scale
Max post-trigger position: Full scale
Max full voltage scale: 10V/div ±35V input range
Min full voltage scale: 20mV/div
Range: ±35 V
Signal coupling: AC / DC
Precision: 8 bit
Input impedance: 1 MOhm // 10 pF
Waverforms: 200 waveforms/s
Data delay to host: