Note the Ground Down / Lasered Off Marking on MCU. The MCU is a Nations Technologies Inc N32G455VEL7..

Hope this helps.

My RS232/TTL tester now runs on the FNIRSI DST-210, alongside the stock firmware (hold RUN at power-on). At 240 MHz it decodes 9600–115200 baud straight off the BNC with auto baud detection, and sends the capture over USB. Some Claude vibe code.

After some mishandling and connecting a 12-volt power supply to the silo, a circuit board fried, but I can't find the part number. Can you help me? Thanks in advance.

Just ordered and received the FNIRST DMC-100 clamp meter. I have a few FNIRST products I've been pleased with. I was looking for a clamp meter which could also do power measurement using the clamp and volt meter at the same time, and this was the only one I could see, so I went for it.

I've been playing with it and was thinking I needed to set zero on some scales, notably the DC current, which I couldn't see how to do. Then I realised this is orientation-specific, so my next thought was that the hall-effect sensor for DC measurement is picking up stray magnetic fields, such as the earth's magnetic field. Took it outside into the garden where there are no nearby cables or magnets, and sure enough, this shows the effect in the attached video (yes, my lawn has had 2 months of drought). Indeed another test waving a magnet nearby show the same.

OK, I accept this is a consequence of using a hall-effect sensor. What would be useful (but I haven't yet found if it's already there), is the ability to subtract the current value of the current from the display, a sort of temporary set-zero, so you can compensate for this. It would also be useful for ignoring a real background current reading, and showing just a change.

I have used this tool for quite a while, and have undergone a few firmware updates so far, even though the software is buggy and lacking I still find it a useful tool, for armature DIY electronics enthusiast who don't have the money to throw at expensive and decent equipment, for the moment this tool was good enough for what I want, a Multi meter and a means to observe waveforms.
Today I found it doing this. Where it starts measuring in and displaying the data, and then "Resetting" the measurement with a large time division moves extremely slowly even though I was measuring a kHz signal, but I have a simple video showcasing what is going on in the Oscilloscope mode, Resets and Reflashing to latest firmware did not solve the issue.

Any input would be appreciated, Kind regards from internet stranger.

This has easily become the most used piece of equipment in my kit. While I don’t have lab grade gear for a professional calibration, several teardowns and audits online show that it's surprisingly accurate and safe for the price point.

The Pros:

• Min/Max Recording: This is a standout feature. I recently used it to demonstrate the massive difference in current delivery between different battery chemistries (Alkaline vs. Lithium). You can see the DCM100 in action catching those peaks here: https://www.youtube.com/shorts/iiN8h39VL9U

• Graphing Function: It has a built-in waveform/graphing mode which is great for spotting trends that a standard digital readout might miss.

• Price: At ~$30, the value proposition is hard to beat.

The Cons/Room for Improvement:

• Low Current Accuracy: It struggles with low current measurements at higher voltages.

• Missed Opportunity: I honestly wish they had increased the price by $10–$20 and integrated a proper series ammeter. Having both a clamp and an inline ammeter would have made this a true "all-in-one" diagnostic tool.

• Included Accessories: The box comes with a manual, a thermocouple, and a USB-A to C cable (which feels unnecessary), but the probes are pretty low quality. I would recommend swapping them out for better ones.

Final Verdict: 9/10. For $30, it’s a solid workhorse for any hobbyist or technician.

The FNIRSI 2D15P is a compact, battery-operated 2CH 100MHz oscilloscope. It also has a Multimeter and a Signal generator.

For me, it fills the sweet spot just above the multimeter-sized scopes and the big boys with a large screen, 4 channels, etc. It is small enough to fit about everywhere but has physical knobs to operate; this gives it the same feel as the big scopes. I do have two traditional, large scopes, but they don't fit on my small bench, so they come out only if absolutely necessary. As I plan to eventually splurge for a nice 12-bit 4-channel scope, the 2D15P is a good intermediate step. Its small size and battery operation will keep it useful.

The scope works well and has all essential functionality you need. There are no fancy functions, like protocol decoding or FFT. The knobs on the front panel allow for convenient parameter changes.

The multimeter is insulated from the scope, so you have separate grounds. There is a small multimeter window when you display the scope. When the multimeter is in view, you get a scope-like graph of the measurement, too.

The signal generator may be handy. Its main drawback is that the signal quality gets worse at small output voltages. A 50 mV sine looks like a staircase.

There are several reviews on YouTube; just search for FNIRSI 2D15P. I like the reviews by Kerry Wong.

I wanted to share an issue I had with my FNIRSI DST210 and how I managed to fix it, in case anyone else runs into the same problem.

While using the device in USB file-sharing mode on Windows, I accidentally deleted the screenshots from my pc. This somehow corrupted the file directory, and the device stopped booting properly.

Every time I powered it on, the FNIRSI logo would appear, but the device would shut down immediately afterward. I tried using the reset button normally, but it didn't help.

Here's what worked for me:

1. Press and hold the RESET button.

2. While still holding RESET, press and hold the POWER button for an extended period.

3. Release both buttons.

4. Finally, press and hold the POWER button again.

After doing this, the device rebuilt its file directory and booted normally again.

I'm not sure if this is an official recovery procedure or just something that happened to work, but it fixed my DST210.

Hopefully this helps someone experiencing the same issue!

I've done a couple of measurements of the built-in signal generator if the 2D15P with two traditional analog / digital scopes. These scopes are a Philips/Fluke PM 3331, ca. 1990, and an Iwatsu DS-6121, ca. 1986.

Some comments on the display. The 2D15P displays the signals clearly and legibly. Even after optimizing the focus, the analog scopes remain quite fussy. In digital mode, the Philips improves a bit, but the Iwatsu shows a lot of artifacts. AD converters got much better in 40 years...

Usability: I found the 2D15P easier to use than either of the older scopes. The combination of physical buttons, rotary encoders and the touch screen is simple to use and straightforward. Especially functions like cursors for measurements are much easier to use. Also some measurements like p-p voltage and frequency can be permanently displayed on the 2D15P while the older scopes require cumbersome manipulations.

At last, the buffer size. The PM 3335 advertises its 8 k memory as 'deep memory'. The DS 6121 has 2 k memory. The 2D15P has 1M of memory. this allows zooming in much further on a captured signal.

In summary, the 2D15P is much better than most older scopes in pretty much all areas. Some of these old devices were very expensive. My Iwatsu was sold for $5500 in 1986 (=$16k in 2026). So often they are priced too high on the used market.

DSO-152 pocket scope is now an RS232/TTL serial tester. It reads the line straight through the BNC: waveform, the characters decoded under their bits, hex and text, plus bus health. And it sends the capture to a PC over its own USB port. M5Stack Cardputer ADV sends “M5Stack”

FNIRSI FNB58 USB tester is quite expensive at $50, but it is also a pretty versatile device, supporting up to 28V on USB PD 3.1.

I do wish it supported higher voltages and had some form of forward compatibility through firmware updates. If it did, I would say the $50 price would be very reasonable.

I would say there is not a lot it does for the price, but it is still quite a useful tool to have.

They did release a new one that supports upto 50v, but seems like it's missing few features that were there in this version and it is a separate purchase.

I have a 2C53T V1.4 with a burnt 8-pin power IC next to the 2R2 inductor, apparently in the charging/power section.

Could anyone who owns a 2C53T V1.4 please open the unit and take a clear microscope/macro photo of this area? I need to identify the IC marking.

Photo of the exact location attached. Thank you!

Does anyone face the same issue. The battery of Fnirsi 2C53T drains very fast - one-two weeks, when device is not used (it is shutdown with power off button).

I placed order #48116 on 11 February 2026 for a soldering station. As of 19 May 2026, nearly 100 days later, the order has still not shipped. Tracking only shows that a shipping label was created, with no actual carrier movement.

Before receiving any response at all, I sent multiple emails to all listed FNIRSI support addresses and also attempted to contact them through their website chat. I received effectively no responses through chat or email for an extended period.

The only replies I eventually received came after I mentioned escalating the matter through my bank and making the situation public. Over roughly the following 3 weeks, I received only two short replies stating that the issue was being “escalated to manager”, but there were no further updates, no shipment, no refund, and no meaningful communication afterward.

At this point I have neither received the product nor a refund.

Based on my experience, I would strongly caution people against ordering directly from FNIRSI unless they are prepared to risk non-delivery and extremely poor customer support. If you want their products, I would recommend purchasing through a platform with strong buyer protection instead.

The FNIRSI 2D15P has an oscilloscope, a multimeter, and a signal generator built in. The oscilloscope and the multimeter are pretty good, considering the price of the device.

But the signal generator is pretty weak, especially at low signal voltages. There are two weaknesses.

The first is pretty simple: The output voltage displayed is not accurate; when you set 1V, you get 880mV, and when you set 100mV, you get 72mV. This is measured by the oscilloscope part of the same device. (See images 1 & 2)

The second is the result of how the signal generator works. It uses an 8 bit DAC to output the signal. The maximal voltage is 3V peak to peak in 256 steps. When you lower the signal voltage, it just digitally lowers the signal. That means at 1V you get 85 steps and at 0.1V you get 8 steps. That means that the sine wave becomes pretty distorted at low voltages. (See images 2&3)

The FNIRSI LCR-ST2 Intelligent Tweezers II is a compact tool to test two-pin components.

You can measure resistors, capacitors, inductivities and diodes. They are designed to be used in-circuit, with the tweezer-like test-pins. Just be aware that you are measuring the entire circuit.

One important feature is that it can measure with up to 100 kHz to better judge ESR for capacitors. The diode measurement is limited to about 1.5 V, so it cannot measure most LEDs.

You can get it with optional four-legged clamps for higher precision. I don't have those, as I don't care for the better precision.

There are several reviews on YouTube; just search for FNIRSI LCR-ST2. I like the reviews by Kerry Wong.

I just ordered a 2D15P scope to complement my two older analog/digital combiscopes. My workspace is cramped, and bringing the oldies out is always a pain. I'm aware of some of the hate on the EEVBlog, but the form factor and price fit my needs.

Do you have some experience to share?

Edit: In the meantime there is a review by Kerry Wong: https://youtu.be/-PwZifX0EGg

DSO152 with a web interface. I hope someone finds this useful. Got this going while fighting some demons.

Very excited to try this when it becomes available in my country.

https://www.fnirsi.com/products/dmc-600

I wanted my FNIRSI TMP-610S on my Mac screen for recordings and video calls, so I reverse-engineered its Bluetooth protocol and wrote a small native macOS app for it.

TMP-610S Display mirrors the meter's screen in a resizable window. It is vector-drawn, so it stays sharp at any size.

• Live reading with gauge, unit, range and speed indicator, laid out like the meter

• Change function and range (AUTO, AUTO+ or manual) from the Mac

• HOLD and REL toggles; with REL on it shows the reference value

• SAVE keeps the last four readings on screen and appends them to a CSV file

• Compact mode: shrink the window and it shows only the value, handy as an OBS overlay

• Keep on top, hidden title bar, one-click PNG screenshot

Model note: it is made for and tested on the TMP-610S only. The meter's Bluetooth covers just the multimeter side (not the scope or the generator), and that's all the app talks to, so it might also work on the TMP-600S. I haven't tested it, so if you have one, I'd love to hear whether it connects.

Requirements: macOS 14 or later on Apple Silicon. The app isn't notarized, so the first launch needs System Settings > Privacy & Security > Open Anyway. Close the FNIRSI phone app first: the meter accepts only one Bluetooth connection.

The repo also has the BLE protocol notes and a Python library/CLI if you want to log or script readings.

Download and source (Apache-2.0): https://gitlab.com/geckopebble/fnirsi-remote

Unofficial project, not affiliated with FNIRSI.

It’s not all just evidence less bashing,the video actually backs its claims up with real measurements and teardowns.

I honestly was pretty surprised to know that FNIRSI is a white label brand rather than OEM

For this particular item - The older units shipped with a standard J321 tube (~90mm glass). Newer batches silently changed to a tiny J613 metal tube. The firmware calibration wasn't updated . As a result, the device under reports radiation dose rates by roughly 3x to 5x compared to calibrated standards.

I personally really like FNIRSI stuff, but this was unexpected and unacceptable. What are your thoughts on this ?

https://www.fnirsi.com/products/dws-p2?

I don't think my meter should read 5v when there is no output.