The DSO-500K is a 2-Channel 500kS/s oscilloscope with a maximum analog bandwidth of 150kHz. The highly rated Scoppy Android app is used to control the scope and display the waveform data. The oscilloscope connects to your Android device via USB or Wi-Fi.

Specifications

• Up to 500kS/s sample rate (250kS/s with both channels enabled)
• Analog bandwidth: 150kHz
• Record length: 2048 samples per channel in RUN mode, 100kS total for single shot captures
• Input Impedance: 1MΩ / 22pF
• Maximum Input voltage range: +/- 6V (1X probes)
• Coupling: AC/DC
• Connectivity (to Android device): USB, Wi-Fi
• Display Modes: YT, FFT, FFT+YT, X-Y, X-Y+YT
• Trigger Types: Rising edge/falling edge
• Trigger Modes: Auto/Normal (Run Mode + Single captures)
• Cursors: YT and FFT horizontal and vertical cursors
• On-screen measurements: Vmin, Vmax, Vpp, Frequency, Period, Duty
• Snapshot measurements (screen or sample record): Mean, DC RMS, AC RMS
• Export data format: CSV
• Access to all pins of the Raspberry Pi Pico
• Signals can be input via 0.1” header pins or BNC connectors
• Signal generator - square wave up to 1.25MHz, sine wave - 1kHz
• AC and DC coupling of the input signals
• Indicator LEDs: Status, Wi-Fi and Trigger
• FFT Window functions: Hann, Hamming, Blackman, Rectangle
• FFT Vertical units: dBm, dBmV, V
• Logic Analyser: 25MS/s (requires soldering extra headers to the board - not supplied). No protocol decoding as yet.
• Unlocks all premium features of the Scoppy Android app (i.e. upgrading to the premium version of the app is not required)
• See the Scoppy project on GitHub for the features of the Scoppy oscilloscope firmware and Android app

What you'll need

• An Android device that's running Android version 6.0 (Marshmallow) or higher with the Scoppy app installed. The device must also support USB OTG (On-The-Go) - most modern phones/tablets do. If you are able to install the Scoppy app from the Play Store then (Google thinks) it does support USB OTG.
• A compatible OTG cable/adapter (you can buy one from us or supply your own). Even if you are planning to use Wi-Fi, I highly recommend having a compatible OTG (On-The-Go) cable so you can access the firmware settings in the event you can't connect via Wi-Fi (eg. if your Wi-Fi password changes or the Wi-Fi settings in the firmware were entered incorrectly). The OTG adapter plugs into the USB port of your Android device.

Open Source Hardware

The hardware is open source and you are free to install your own firmware onto the embedded Pico W board (however, if you do this you are on your own as we can't provide support for custom firmware).

Please Note:

• Android device and scope probes are NOT included

Features

Triggering

The DSO-500K supports AUTO and NORMAL trigger modes and RISING EDGE and FALLING EDGE trigger types. The trigger level is set either by dragging the trigger indicator, tapping the trigger level buttons or tapping the trigger badge at the bottom of the screen. Long-pressing the LEVEL button will set the trigger level to the center of the displayed waveform.

Cursors

Horizontal and vertical cursors are available in both YT (ie. normal oscilloscope) and FFT modes. In YT mode, the horizontal (X) cursor measurements include position, period and frequency. Vertical (Y) cursor measurements include the voltage and the delta between the two cursors.

FFT

• Window functions: Hann, Hamming, Blackman, Rectangle
• Vertical units: dBm, dBmV, V
• Separate adjustments for start/stop frequency, center, span and vertical scale and position
• Tap and hold the SPAN, CENTER, SCALE and POSITION buttons to set these to their default values
• The FFT and YT views can be displayed simultaneously

X-Y Mode

Standard X-Y mode as found on most oscilloscopes. Also includes a LINES option to join all samples points with lines instead of displaying individual dots. This can make the output look much nicer for some signals.

The X-Y mode view can be displayed simultaneously with the YT waveforms.

Roll Mode

Displays the waveform data as it is captured instead of waiting for the complete waveform record. Roll mode is automatically activated when the Time/Div setting is 100ms/div or more.

Single shot captures

Pressing the SINGLE button will capture a single waveform record of up to 100k samples. Can be used with either AUTO triggering (to capture the waveform immediately) or NORMAL triggering (to capture the waveform after a trigger event occurs).

8-channel Logic Analyzer

Headers can be soldered to the board to access the Logic Analyzer inputs. The logic analyzer sample rate is 25MS/s and the maximum voltage is 3.3V.

Protocol decoding is not available but the waveform record can be saved and imported into other software (eg. sigrok/pulseview).

AC/DC Coupling

Removing the jumpers from the DC coupling pins will enable AC coupling.

Measurements

On screen measurements include Vmin, Vmax, Vpp, Frequency, Time (Period) and Duty Cycle for each channel. Tapping the measurements will open the configuration screen. The configuration screen can also be accessed via the channel badges.

Measurements can be displayed for a single waveform (snapshot). These snapshot measurements can encompass the entire sample record or just those samples displayed on the screen. The measurements available include Vmin, Vmax, Vpp, Vmean, Vdc-rms, Vac-rms, Frequency, Period and Duty Cycle. The snapshot measurements can be displayed by long-pressing the on-screen measurements or via the channel badges.

Signal generator

The signal generator can produce square waves of between 10Hz and 1MHz or a PWM encoded sine wave of 1kHz. The PWM encoded sine wave can be converted to an analog sine wave using the onboard low pass filter.

Documentation

Detailed documentation is available for the app and hardware. While the intuitive user interface of the Scoppy Android app means it can easily be used without consulting the documentation, you might - for example - be interested in discovering the five different ways of changing the horizontal timebase. We encourage you to check out the independent reviews of the app on the Play Store.