Fit a Digital Camera to an Analog Oscilloscope for DSO Functions

Some engineers and hobbyists prefer to use old reliable tools and equipment over their modern-day counterparts. Programmer and electronics hobbyist Joseph Eoff are one of those who would rather hang on to his over 30-year-old Telequipment D43 cathode-ray oscilloscope, rather than upgrade to a digital version. "The D43 is cantankerous and not what you'd call precise. That's OK. I'm cantankerous and not overly precise, either, so we're a good match," Eoff explains. "I don't do much with high-frequency stuff, so the 13MHz bandwidth is sufficient. The D43 has a slight advantage over most modern scopes in that it has a 100 microvolt per division voltage scale."

While his old D43 is a beast, it does have its limitations, including the ability to grab screenshots of measurements. Telequipment did make a camera for the D43, but they are difficult to come by, so Eoff did the next best thing and fitted a digital camera to the o-scope using a 3D-printed housing (note the original prototype on the right, which was scrapped). His current version uses a Logitech C270 HD Webcam, which lets users adjust the focus when the housing is removed; otherwise the 3D-printed would have to be as long as the shortest distance the camera can "see" for a fixed camera.

Eoff paired the camera with a cross-platform custom code he created using the PyQT5 toolkit and OpenCV to capture images from the oscilloscope and uses NumPy to manipulate them. For those interested, Eoff has uploaded a detailed walkthrough of his Telequipment D43 camera solution on his project page.