[Industrial-Grade Accelerometer+Inclinometer] HWT901B-TTL MPU9250 9-axis Gyroscope+Angle(XY 0.05° Accuracy)+Digital Compass+Air Pressure+Altitude, RM3100 Magnetometer Compensation and Kalman Filtering

I have two WIT devices, this one, and one that is IP67 waterproof. Both provide good, reliable measurements that are sufficient to drive my boat's autopilot. There's a learning curve as there is with anything new. But the curve is not too steep. The Help provided by WIT is really outstanding. Download the GitHub package, install it on your Win PC, and go from there. Basically, there's an application that allows you to calibrate/reset the unit, and monitor its functions (GitHub). If you're a programmer, there's also Visual Studio, C# projects you can play with. All in all, this is a great value for the money.

I can't get this sensor to communicate at speeds other than 9600 baud. Even the company's own sample codes can't communicate with it out of the box.The software samples from this company, while they continue to improve, are fair at best.I purchased this sensor to replace one that had failed (failed sensor was from same company). I had high hopes this would be a simple replacement without any changes to code to get a new sensor to work.Guess I'm returning this sensor...sad.

I really like this product. It is everything that is advertised. The after sales service was terrific. Kyle, the company representative held my hand and guided me for the successful operation of this product. I actually could have done it my self since it was so simple but I was just too lazy and took advantage of the great support they give !I am very happy with Wit motion product and especially with Kyle's great after sales support ,

I received the product quite fast. However the cable adaptator had not its ends correctly fitted with the plastic covering. I had to fasten them as they were too loose. Next I could not find on the web site of Wit motion the manual user of what I got, only a very sketchy item with no explanatory text. Finally the PC software I could load on the web site seems to be in chineese and I cannot download an english version of it. So, for the moment, a cheap but useless product. If the seller is able to correct these problems, I'll change my opinionwell, after some efforts I could use the chineese installer (blindly!) get the program installed and pass from the chineese to the english language. The sensor works OK but adjustements in the software are not really intuitive.

I'm using this in my car with an Android head unit that lacks its own compass. The RS-485 version is compatible with the car's 12 volt supply, and the unit could be placed far away but I found a close spot for it without too much magnetic interference. I learned its important to calibrate according to the instructions.

Spent a fair bit of time with this before writing a review.On one hand, it's pretty pricy for an MPU9250. No matter how many times they say "Industrial/Military" grade and "High Performance"- it simply is not. Sensors that meet those requirements are several thousand dollars (see XSens, LORD Microstrain, SBG, etc)- and that's for mid-grade models. So, a sub-$100, with barely any published specification of meaningful parameters and claiming high-performance and military/industrial grade is an exaggeration.On the other hand, it eschews the internal magnetometer of the MPU-9250 for an RM3100, which is a decent magnetic sensor and that, along with a nice metal enclosure and UART to USB-A converter justifies the price point. HOWEVER: the UART to USB converter that came with mine was dead on arrival. I wasted a lot of time to figure that out. Also, it did come with a calibration sheet (which they call "Product Inspection Report")- this was surprising and very appreciated. I don't recognize the standard (QJ 2318-1992), but assuming there's some rigor behind that, it's a plus and not expected at this price point. However, the only parameters appearing in cal sheet are X and Y angles.Some random thoughts on this:1. This is a black box, both figuratively and literally. Doing a google search, I found a picture of the circuitry inside the box- I'm not posting it here, since I don't have rights to the picture, but it's easy enough to find if you're interested. Essentially, there's an ARM processor, MPU-9250(?) chip, barometer sensor, and a castellated RM3100 breakout all on a single mainboard. My assumption is that there's firmware running on the ARM chip that's polling the sensors and stores the data in registers that can be accessed over the UART. Therefore, you only ever talk to the firmware and don't have direct access to the actual sensors. That's not an awful approach, however it leaves a lot of questions regarding what's going on in that firmware.2. Where is Kalman filtering/sensor fusion being done? Is this done in the ARM firmware or the Windows software? It's certainly not in the SDK (I'll get to that in a minute) and there's no distinction in the register map (in their gitbook) as to whether the parameters - or which parameters - are filtered or not. This is bad.3. The Documentation, SDK, and sample code are nice efforts, but it leaves a lot to be desired. They get a grade of C-. They do have sample code for C/C++, Java, python, Matlab, ROS(!) and for Arduino, ESP32, and STM32, but these are poorly documented and are often commented in Chinese and don't actually include all the parameters that this sensor can output. While a lot of this can be figured out- using assumptions and good old trial and error, what's the point of an SDK if it's just for superficial stuff?4. The desktop app is windows only and is okay. Like the SDK, there's little documentation for it and even with English selected, some dialogs are in Chinese. There are features that are unexplained and it crashes a lot. It does have the ability to log the instrument data to different file formats- which is a nice touch.5. There is no IP rating for the enclosure. As a result, I'm going to assume it has no water/moisture resistance.6. There's no light or anything to indicate signs of life on the enclosure. It would be appreciated to have some indicator for power and data activity.7. The cable is permanently attached to the housing, though it looks like it's terminated inside to a 4 pin JST connector. So it looks possible to replace the cable if that were necessary.Bottom Line: I think it's priced appropriately for what you get- if you ignore the marketing fluff about professional/industrial/military. Minis 1 Star for the weak effort at documentation and SDK, and minus 1 Star for a DOA UART to USB converter.

Excelente producto, buena precisión aplicación amigable

No English Windows Driver????