OpenScope MZ Development Kit - Review

Table of contents

RoadTest: OpenScope MZ Development Kit

Author: WarrenW

Creation date:

Evaluation Type: Test Equipment

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?: Arduino based simple scope

What were the biggest problems encountered?: In my case the largest problem was getting the entire unit working with my cell phone as power supply via OTG, monitoring software and signal source via headphones.

Detailed Review:

The Digilent OpenScope MZ is a great piece of portable test gear that just needs a few add-ons to make it a truely oustanding budget scope.

 

The kit arrived from Element14 and Digilent (thanks to both for providing me with a nice tool) and when upacked it contained the PCB nicely stashed away within several layers of antistatic foam along with a Multiway cable that has individual pin sickets on one end for easy connection to the likes of arduino signal sources.

The first task I needed to complete was download the software from Digilent, you will need to install the Digilent Agent to interact between the hardware and the browser based software - this unit is supported by the Waveforms Live browser based software. Do not go to the software section and download waveforms! Instead do a search on the site for the OpenScope MZ and click on the resource center then the getting started, from there you will find a link to the Digilent Agent download, choose your flavour and install the software making sure that if you want to use this as an offline system, to select the offline support options during the installation of the agent .

Next read the manuals or better yet visit the youtube resources available from the resource center to view all the good intel on how the product works and how to get up and running. There are a few tricks!

 

Firstly once you have your software installed (I initially used a PC for this) you connect the OpenScope MZ to the USB port (lead not provided) and right click on the Digilent Icon (wavy green circle with a D in it.) choose to check for updates and install any available then select Launch Waveforms Live. This will open a browser and point it to Waveforms Live . Plug in theOpenScope MZ to any usb port.

 

I found some browsers will not display the site corrrectly but it just may have been the machine I was using as it has several filtering components for adverts etc.

Select add device and the agent option (this might change later when  you setup the networking), this probably themost difficult part of the setup.

If you have no luck with your current browser try another.

 

Once connected the agent interacts with the hardware and checks the firmware, it will prompt to install the latest firmware prior to accessing the device. You will also need to link up some of the leads and perform a calibration.

The device will then be listed and you can open it to display the user interface. It is worthy of note that Digilent has included a simulation mode that allows you to explore the software and the operation of the hardware without the need to purchase any hardware.

This means you can go through the youtube videos and perform the steps shown just by visiting the wbesite, nice touch!

 

The OpenScope has several areas of interest that I have tested and believe the results to be a very fair indication of how well this device performs under set parameters.

  • Dual channel Oscilloscope
  • Arbitrary waveform generator
  • 10 channel logic analyzer
  • 10 channels of GPIO
  • 2 programable power supplies

This thing packs a punch for a physical package that measures about 70mm x 70mm !

 

Of specific interest to me was the waveform generator and the dual channel scope for audio work. I will try to test the logic analyzer and update this roadtest or post it on my blog when I can have a chance to test these features and make sense of them.

 

So to the chase!

My aim was to get the ue OpenScope running on my cell phone using the phones display and linking to it via the wifi hotspot thereby allowing this to be a truely portable item of test equipment.

To achieve this you would need a cell phone with OTG capability to allow the external device to be powered from the phones charging port.

This is where it got a bit tricky. The phones hotspot had to be enabled, then the network connection needed to be setup via the PC to connect to the phones Wifi hotspot . Once completed I then had to search the phones assigned network addresses for the OpenScopes IP address.

This is the address you will need to use for connecting when using the phone as the display (use network settings on the waveforms live page).

 

Setup the connection on the phone and you then have a means to connect to the OpenScope MZ from your phone using the Waveforms Live softwar e.

 

I then tested the waveform generator and was pleased to see that by looping it back into the Scope input you could see the waveform that was being generated.

 

The wavform was checked for cleanliness on an analogue oscilliscope and it was nice and crisp.

The accuracy of the frequency was checked against a very old counter - so accuracy could be questioned but at 500Hz I think this is pretty good!

At 1Mhz the frequency was out by 9Hz - probably the tolerance of my counter is more than this so again pretty happy.

 

I did get the whole phone / OpenScope deal going and was able to take it to check signals as a totally portable item of test equipment.

For clarity sake and ease of capturing images of the scope in action I used the laptop as the display method.

 

Running stereo audio into the OpenScope I was able to capture a nice set of audio waveforms.

The full captured buffer of data can be seen at the top of the screen with the displayed portion highlighted, scrolling the mouse changes the timebase.

The data capture points can be seen when the timebase is set very short.

The sample rates are independant per channel and can lead to some interesting results.

 

To summarise what I have as impressions of this device.

  • Well made and value for money
  • When coupled with a laptop it is very easy to use
  • Accurate frequency for the waveform generator
  • Sine, Triangle, Sawtootth and square waveforms are easy to generate with a few clicks with the addition of DC offset in 100mV increments for any waveform type
  • Dual power supply rails with a  common 0v rail that can source up to 50mA (increments in 1 mV steps up to 4V)
  • Scope inputs can accept up to + or -  20V
  • Very good at audio sampling
  • You get a 10 channel digital analyser as well - not tested as yet
  • Performs  as per the videos and documentation - very confidence inspiring.

 

Areas where you can add-on value to this device.

  • Put it in a case (the resource center has designs and files for this option) I would make one that I could mount BNC sockets for standard scope leads.
  • Add some additional circuitry to block DC voltage on the inputs as per a 'normal' scope

 

As a great low cost hobbyist tool for Low frequency work this is an ideal way to get a cheap dual channel scope and have some fun and learning while you do some testing.

 

Would I recommend it?  - YES as long as it is used within the design parameters, the same as ANY test equipment.

 

Keep checking back for the digital section - I am now extremely busy so getting this section done may take a while

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