The Probe-Scope Is a 60MHz 250Msps Oscilloscope That Fits in Your Hand
After the release of his PIC32MZ EF based 20Msps oscilloscope with an integrated 1-inch by 1-inch OLED screen for readouts, Electrical Engineer, Mark Omo has again unveiled his new design, the self-contained 60MHz 250Msps Probe Scope oscilloscope with the probe in cable form factor.
The Probe-scope oscilloscope which runs at 250Msps and has a bandwidth of 60MHz was designed to bridge the large market gap between existing low-performance low-cost open-source oscilloscopes and expensive professional closed-source oscilloscopes.
The new innovation to the world of oscilloscopes is in three sectional parts: the programmable gain amplifier, acquisition hardware and, the input /divider buffer. The open-source PIC32MZ-based oscilloscope has its acquisition hardware built in it and plugs directly into a PC via USB. The signal is passed from the input /divider buffer through a fixed 30X divider and buffered through an op-amp to a 15V range. It is later piped over a differential op-amp and added to an offset signal produced by a DAC before passing along to the gain settings of the PGA. The signal is attenuated by an ADRF6518 PGA with a little bit of anti-aliasing before it is sent to the analog devices’ AD9481 ADC to be conditioned and further handled off to a MachXO2-4000 FGPA to be stored into a 128Mb HyperRAM, set for one trigger. From the HyperRAM, a PIC32MZ EF microcontroller connected to the FGPA reads it off and shoots it over USB to a connected PC.
According to Omo,
“The Probe-Scope grows as you grow, giving you as many channels as you have USB ports, the probe scope is almost infinitely expandable to tens (or more!) of channels”. He also stated that the design us ready to be taken to market, stating that, ” the hardware design Is complete; our final PCBs were produced and assembled by PCBWay and functioned as expected right out of the box”. Omo and team are planning on using the same design for volume manufacturing, with only minor changes to the connectors.
As a competitor against Rigol’s DS1054Z digital oscilloscope sold for $350, Omo hopes to keep the cost of the Probe-scope at $100. Meanwhile, a detailed walkthrough of his Probe-Scope project has been uploaded on Hackaday for those who might be interested in building theirs.