You need not spend a ton of money to get a feature-packed oscilloscope, provided you don’t need high bandwidth. While the oscilloscope works well, the free software needs help.
After seeing the Uni-Trend (Uni-T) UTG962E Function/Arbitrary Waveform Generator ($182), we at EE World bought one and, at the same time, ordered a UPO1202 200 MHz oscilloscope ($339). With a 10% discount from a trade show, we bought both for under $500, including shipping. That kept the bean counters at bay.
We were even able to skip a 100 MHz model and go for 200 MHz. We didn’t try for a four-channel model, figuring that the only difference would be two additional channels.
Having reviewed a high-end Tektronix 4 Series B oscilloscope, I didn’t have high hopes for a low-cost 200 MHz instrument. I was, however, pleasantly surprised by the UPO1202’s long list of features.
What do you get for $339?

Accessories included a North American power cord, a USB-A cable, and two 200 MHz oscilloscope probes, as shown in Figure 1. I expected to get 100 MHz probes, assuming 200 MHz would require paying more. Not so. The probes come with the usual removable clip tips and ground wire with an alligator clip. Also included is a ground tip that lets you connect to a nearby IC ground pin or ground pad on a PCB. You additionally get a protected probe tip to minimize the chance of accidentally shorting the tip when probing IC pins.
Aside from the hardware accessories, the UPO1202 oscilloscope packs many features into its firmware. For example, you get a 3@frac12;-digit DMM, pass/fail testing, waveform recording (8 ksamples), and waveform saving for playback, analysis and archiving. For quick documentation of your measurements, use the screen-capture button in the lower-right corner of the buttons shown in Figure 2.

The UPO1202 oscilloscope provides the usual vertical, horizontal, and trigger knobs and settings. Pressing on the horizontal and vertical position buttons lets you return them to their default positions. Pushing on the scale knobs lets you toggle between fine and course adjustments.
The trigger section includes the trigger menu button, which lets you select the trigger type. The oscilloscope provides numerous options, including edge, delay, number of edges, runt, delay, and bus triggers (RS-232, I2C, and SPI). The mode button lets you select among Auto, Normal, and Single triggering. You can also select the single-trigger mode from the Single button in the panel’s upper right corner. More on triggering to follow.
In addition to setting time per division, the horizontal section provides a menu button that adds features such as displaying a dual window. That’s useful when you need to zoom in on a section of a captured waveform.
In addition to the print-screen button, the menu section shown in Figure 2 contains eleven other buttons. Start with the display button, which provides settings that include display brightness (default is 50%), graticule brightness (1% to 100%), backlight, color on/off, and color invert for those who prefer black traces on a white screen. The vector/dot (vector default) setting lets you look at the individual waveform points without the oscilloscope connecting them.
The Multipurpose knob lets you scroll through and select parameters within the settings. Push it to save your selection. Below the knob is a button with a square. That brings up additional options, such as an alphanumeric selection grid for naming signals, setting file names for saving data, and so on. The arrow buttons also let you move through selection options. These buttons will illuminate when active.
The six vertical buttons along the screen’s right side function as soft keys, which change depending on the menu. For menus with more than six options, use the left-right button at the bottom to reach additional settings, then use it again to go back to the top menu setting. Use the Menu button at the top to remove menu settings from the screen and see the full waveform.
Menu buttons enhance signal analysis

The Meas(ure) button in Figure 2 lets you select from parameters that provide insight into circuit behavior (Figure 3), including user-defined parameters. You can set the source to either analog input or to the result of a math function. Figure 4 shows the User Define menu. The oscilloscope provides short descriptions of the options. Here, you can see a description of FFFR. You can use this and the seven other similar parameters to measure the timing differences on signals across channels.
The Acquire menu lets you select how the UPO1202 oscilloscope captures signals. For example, you can choose from normal, peak, high-res, or averaging. When using the averaging function to reduce the effects of noise, you can set it to powers of two from 2 to 8192.

You can also use the acquire menu to select the oscilloscope’s memory depth, which ranges from 7 ksamples to 56 Msamples. An automatic mode lets the oscilloscope choose the memory depth.
As with perhaps all digital oscilloscopes, the UPO1202 oscilloscope includes cursors. Pressing the Cursor button lets you choose vertical cursors for time or frequency measurement (more on FFTs later). Selecting the voltage option lets you make voltage measurements between the two lines.
Figure 5 shows the X-axis cursors in white and the Y-axis in yellow. A table shows the positions of each cursor and the difference between them. For the Y-axis, you can choose to display the difference in time or frequency, which gives you an idea of a rising or falling edge’s frequency content.

Next, we have the bus menu, which lets you decode common bus signals such as RS-232, I2C, and SPI.
Triggering is essential for any signal measurement, and today’s oscilloscope features a wide range of triggers. I wanted to look at digital signals from a USB keyboard as a triggering exercise. To gain access to the bus, a USB breakout board was used to connect an oscilloscope probe. Here’s where a triggering issue arose that took some time to solve.
USB keyboards send a series of pulses at a rate of 2.25 kHz, informing the host that the keyboard is connected. That pulse stream is consistent, repeating every 444 µsec. When you press a key, the keyboard sends an additional and unique pulse stream for each character. Triggering on those intermittent pulses presents a challenge. You can’t use a simple edge trigger because the oscilloscope will trigger on the initial edge of the 2.25 kHz pulse stream. All pulses have the same amplitude, so there’s nothing unique about the intermittent pulse streams.
Unlike a high-end oscilloscope, the UPO1202 oscilloscope and others in its class lack a box or zone trigger, which lets you draw an onscreen box that initiates a trigger whenever a signal enters or exits the box. Higher-end oscilloscopes have touch screens and mouse controls for drawing such a box. Inexpensive oscilloscopes have neither.
Given that the keyboard produces the same pulse stream every time, you can view one pulse series and count the rising edges. In this case, there were 18 (Figure 6).

Using the Nth Edge trigger, I set the oscilloscope to trigger whenever it saw 20 rising edges and used single-capture mode. That let the instrument trigger when I pressed a key. The animation in Figure 7 shows a sequence of two keystrokes.

Math and FFT
The UPO1202 oscilloscope packs a wide array of math functions, including log, sin, cos, and sqrt (Figure 8).

An FFT function is available through the Math button in the vertical section of the front panel. It lets you choose the frequency range in two ways. You can either set the high and low-frequency limits, or you can set a center frequency and range. I used a frequency range from 500 kHz to 10 MHz on a 1 MHz square wave in the video below:
The video shows three windows you can attain this through the Horizontal button. The next video shows the square wave (upper right), its FFT (lower trace), and a spectrogram (upper left) that can show time variations of frequency. The colors in the scrolling window correspond to the amplitude of the FFT frequencies. The fundamental frequency appears in red because of its high amplitude relative to the harmonics.
When using an FFT, you often need to use a window to view desired frequency characteristics and limit discontinuities. The UPO1202 oscilloscope lets you select from popular Hanning, Hamming, Blackman, and rectangular windows. Not sure which one to use? Then use the Help button and scroll down using the Multifunction knob to the FFT section. There, you’ll find brief explanations with tradeoffs in choosing an FFT window.
While color represents amplitude in the spectrogram. In the time domain, the oscilloscope’s digital phosphor feature uses color to indicate how frequently a signal illuminates a particular screen pixel. That’s helpful for identifying intermittent signals or seeing variations in a signal. Figure 9 shows colors in the square wave’s tops and bottoms, indicating some noise.
Hardware/firmware suggestions
The UPO1202 represents good value, providing many features for little money. Engineers designing IoT devices, embedded systems, audio, analog, or power circuits who don’t need logic inputs can use this instrument. Its math, FFT, bus decoding features, and ability to save waveforms help you document your designs and analyze signals.
While the display provides a great deal of information, I’d like to see a display of the selected FFT window. Otherwise, you will need to write it in your notebook.
I used a USB flash drive to save the images for this article. That’s a useful feature. Just remember to remove it before turning the oscilloscope on. If you boot the UPO1202 oscilloscope with the flash drive plugged in, it will fail to start. Perhaps that’s how the factory loads the firmware into the unit during manufacturing.
As with anything that packs many features into a limited number of controls, the oscilloscope can get a little confusing to use at the start. Several times I was lost trying to find features or couldn’t remember how to undo something. For example, I set up a dual window to see which portion of the waveforms was displayed but didn’t recall how to undo the small window. It’s in the horizontal settings. Now, I’ll always remember.
Continue to page 2 for a software review.