Oscilloscopes can be an electronics engineer's best friend. These highly versatile tools are helpful, from basic debug to verification tests to compliance checks for standards. Not only are their measurements varied, but so are their form factors. Two common styles are "bench" scopes, which go on a bench, and PC-based oscilloscopes, which, until now, have primarily used USB. An Ontario-based EE graduate student, Aleska Bjelorlic, is launching a Crowd Supply campaign for an open source software-defined oscilloscope. The four-channel ThunderScope has up to 350 megahertz of bandwidth and can stream acquisition data to a PC at one gigasamples per second.
Since we last covered ThunderScope, Bjelorlic and friends have further developed the hardware to a near-final state and have continued extensive work on the software side.
ThunderScope comes in an unassuming box that is just large enough to house 4 BNC connectors, a compensation output, four fully-functional front-end stages, an ADC, and an Artix-7 FPGA to capture the data and transfer it to the PC.
A key breakthrough with this design is utilizing the high-bandwidth capability of Thunderbolt. To speed up development, Bjelorlic relied on PCIe as an interface. However, the plan had always been to incorporate USB 3.2 Gen2 and Thunderbolt interfaces to prevent ThunderScope from being trapped inside a desktop PC's case.
ThunderScope's sampling architecture shares a single 1 gigasample/s 8-bit ADC across the four channels. As a result, up to 350 MHz of analog bandwidth is available on a single channel. When using two channels, the bandwidth of each is 200 MHz. And when using three or four channels, the usable bandwidth is 100 MHz.
Like traditional oscilloscopes, the front-end has adjustable voltage steps that allow for ranges from 1 mV to 10 V per division while using a 1:1 probe. We are happy to see that, unlike some USB-based scopes, ThunderScope offers a probe-compensation circuit on the front panel.
Andrew Lapadat developed the software architecture. The primary components are Electron and React, which gives the UX functionality in Windows and Linux. Lapadat already implemented basic functionality like scaling, waveform drawing, and basic math. Users are encouraged to contribute capabilities like protocol triggering and decoding to the ThunderScope GitHub repository.
Pricing and availability details have not been released yet. However, in the extensive project logs, Bjelorlic mentioned a price goal of less than $500. Additionally, the above video from November 2021 says there is a need for at least one more minor board revision. Visit ThunderScope's Crowd Supply page and sign up for updates to know when it becomes available for pre-order.