Pico USB Scope for the Raspberry Pi

According to Pico Technology, the beta release of its drivers for the PicoScope oscilloscopes, useful for running on ARM-based single board computers, is available. That includes development systems such as the BeagleBone Black and the ever-popular Raspberry Pi, also known as the RBPi. For the RBPi, the drivers are a specialized armhf build under the control of its Raspbian OS. Pico Technology is offering this Beta release with some caveats.

Although the developers claim to have taken care of ensuring implementation of almost all the driver features, they may not work in all cases. The developers mention that the recommended systems requirement for the drivers specifies resources that most embedded systems will not be able to fulfill entirely. That means when the system is busy, the driver may not have enough resources for processing the data, which may result in the device being dropped or the application to hang. They also expect power surges, fuse blowing and port damage and to guard against this, they suggest powering the system through a separate USB hub.

All this makes it sound like the drivers are more suitable for advanced do-it-yourself people. It also suggests that the drivers are useful for working on other platforms, but Pico may not yet be in a position to offer support for these implementations. At present Pico is focusing their support for only two platforms – the RBPi and the BeagleBone Black.

The Pico USB Scope has advanced display software that assigns almost all the display area to the waveform. Therefore, the user is able to see the maximum amount of data at a time. Additionally, this makes the viewing area much larger and of a higher resolution than that available on a traditional bench top oscilloscope.

The large display area also makes it easier to create a customizable split-screen display for viewing multiple channels or for projecting different views of the same signal simultaneously. The software is capable of displaying both oscilloscope output and spectrum analyzer traces at the same time. Moreover, the software can flexibly control each waveform individually for zoom, pan and other filter settings.

Oscilloscopes frequently require using an analog or DC offset. Most PicoScope Oscilloscopes offer this valuable feature. With DC offset, you can get back the vertical resolution, which is usually lost while measuring small signals. In practice, an analog offset typically adds a DC voltage to the input signal. This is useful if the signal is beyond the range of the ADC of the scope. By adding an offset, the signal is brought back within the range and the display can use a more sensitive range.

For testing purposes, an AWG or arbitrary waveform generator is often required. This generates electrical waveforms that can be either a single-shot or repetitive. With an AWG, you can generate any arbitrarily defined wave shape to inject into a DUT or device under test for analysis by the PicoScope. The progress of the signal through the DUT confirms its proper operation and enables pinpointing any fault inside.

Deep-memory versions of the PicoScope oscilloscopes offer waveform-buffering sizes up to 2 gigasamples, which is much larger than that offered by competing scopes of traditional bench top or PC-based design. A hardware acceleration technique ensures the PicoScope does not slow down while using deep memory and displaying at full speed.