Bluetooth module for the Fnirsi FNB48 USB tester and a brief look at the software

Not long ago, I posted a review of the new model of the Fnirsi FNB48 USB tester and mentioned that both a Bluetooth module and software for it were expected. I received the module quite a while ago, but the software only arrived now, just as promised, so today I'm adding to my previous review.

Unfortunately, the module isn't sold separately. As I understand it, though, it was sent free of charge as a bonus to the first 100 buyers, and I got one too. New buyers can choose either the tester alone or the tester with a BT module; the price difference is $6.


It came packed in a foam box, so it would have been very difficult to damage in transit. Inside was a small circuit board.


The module is a board similar to the original lower board; even the markings on the back are exactly the same as on the one included with the tester.
I described a similar approach in my review of the ZY1276 tester, but there I had to buy the BT module separately. The additional board also had space for connecting a battery.

Here, it's simply a small board with a BT module soldered onto it, based on an RS02A1 chip I've never come across before. There is some information about it online, though. The 1276 used the more familiar HC-05.
It connects via four spring-loaded contacts, and there's also a small switch nearby.


To install it, remove the four screws, take out the old board, and put the new one in its place. In other words, all you need is a screwdriver. The switch will be on the top edge of the case, but it's so tiny that it's easier to just turn it on and leave it on, especially since it draws only 1–2 mA.


The manager also immediately sent me a link to an archive containing the Android software, instructions, and a new firmware version. When I asked when the PC software would be available, he said it would be after their New Year.

I copied the file to my phone and launched it. The software installed, then automatically started searching for devices, but at first it only found some neighbors' TVs.


I had to connect the tester to a computer and update the software from version 0.6 to 0.9. While I was at it, I opened the menu and double-checked that Bluetooth was enabled in the settings.


After that, the software found the tester without any problems, and interestingly, all the other “extra” devices disappeared.
Next, tap “Connect,” then “Login,” and you'll get to the program's main screen. There were also language settings on the previous screen, but the software launched in Russian automatically for me.


At first, the software showed some inexplicable 5 V and 1 A. It turned out I also had to tap “Start” in the upper-right corner of the screen.
After that, everything worked normally: the current measured values appeared on screen. I also found that the software only works in portrait orientation; it doesn't respond to screen rotation. Given how it's designed, though, it might actually be worse if it rotated.

To display the graph, tap “Start” below it. Unfortunately, even with the minimum setting of 1 s/div, the maximum refresh rate of the “waveform” is about 8–10 times per second. I was hoping they'd include an actual oscilloscope mode.
The VA and D+D- buttons select whether to display the measured current and voltage in the power circuit or the voltage on the data lines. CH1 and CH2 turn the current and voltage traces on the graph on and off.


Also, the graph is really tiny; it's clearly much larger in the description. I can't figure out how to enlarge it. My smartphone's screen resolution is 1920x1080, so that may be the reason. Along the way, I noticed that the picture in the manual is mirrored :)


There’s a function for controlling fast-charging protocols. For some reason, activating it initially switches to Huawei mode, but after you select the output voltage, it switches to QC. I couldn’t select any other protocol.
When I tried connecting it to a PD charger, I found that the tester only controls QC mode: I couldn’t set the voltage above 12 V, even though the charger can supply up to 20 V in PD mode.


There’s a brief hint about the protocol-control function, and a warning appears when you turn the mode on or off.


You can also access a mode for measuring the capacity of power bank batteries. It all works well and is convenient, but as I’ve already mentioned, there’s a calculation error.
I may be wrong, of course, but I checked again: after setting it to discharge for 30 minutes, the tester measured 0.267 Ah. The output was about 5 V, the input was set to 3.7 V, and the efficiency to 90%.
By my calculations:
0.267/3.7x5=360 mAh, without accounting for efficiency
360/0.9=400 mAh
But the tester showed 320 mAh...


And finally, a rather unusual mode: an alarm that triggers when a parameter goes outside the set limits. You can set the operating voltage range and maximum current, and enable an audible alarm and/or vibration. The “disable alarm” switch actually turns it on.
The function works: the phone beeps and vibrates if, for example, you set the minimum threshold to 5 V and the voltage then drops to 4.9 V. If the readings return to the allowed range, the alarm stops.


That’s about it for now.
To sum up, the function works, and I have no complaints about the stability of either the module itself or the software. I turned it on and off, lost and restored the connection, and the app worked without errors.
But in my opinion, the app is very basic. It needs an oscilloscope mode, full protocol control with protocol selection, a logger that can save to a file, and graph scaling.
Frankly, it’s missing quite a lot, and you can tell the developers rushed to release it. On the other hand, I was told before New Year’s that the software would be ready in 45 days, and they got it done in 30. Still, it clearly needs more work.

I don’t know what the PC software will be like, or how much this software will be updated later. But in my opinion, even if you don’t get the Bluetooth module, you won’t be missing out on much, at least for now.

And of course, there’s still the question of whether the power bank battery capacity measurement (calculation) is accurate. I also didn’t notice any difference in how the tester works with the new firmware version; I think they only added BT support.

That’s all from me. I hope this was useful, even if brief :)