The unit was delivered on time despite the holiday season traffic. The cal procedure is well described, even for an Arduino novice no problems at all. I sought for a small USB controlled linear load. To my surprise MightyWatt offered exactly what I needed. And now that it is sitting on my bench I am surprised how well it performs. The accompanying software appears to be well designed and is pretty handy for most standard DC load tasks, at least for what I can tell after a few hours testing. All in all: Well done Jakub! Looking forward to more projects with MightyWatt...

I bought MightyWatt in order to build a hardware prototype for charging and discharging a single Li-Ion battery. I needed a device which parameters can be set to different values at any time. Fortunately I found MightyWatt, which is a perfect solution for this project. I am giving the highest rating for each category and I can ensure you that both the designer and the product deserve it!

Product:
MightyWatt works exactly as the designer describes it. Load parameters (voltage, current, power and resistance) can be set very precisely and the measurements are very exact. I connected a calibrated voltmeter and ammeter into my circuit and the readings are the same as these from MightyWatt. The size of the load is very small compared to commercial products and it's also incomparable cheaper. There is a documentation describing how to assemble and calibrate it, so even someone who doesn't have much experience in working with hardware, could do that. Just need to follow the steps which are written very clear and in an easy way and really everyone will understand them.
The software is also very user-friendly and easy to work with. After connecting MightyWatt to Arduino, uploading a sketch and connecting it to the battery, you just write a parameter and its value in a manual mode or program it (so that you can start a customized scenario for your tests) and that's it! You can set a watchdog monitoring the parameter you entered so if something goes wrong and the parameter exceeds set value, the load will be automatically disconnected. You can also disconnect the load at any time by pressing the "stop" button and start it again at any time - the load responses immediately. Moreover, the designer provided a very useful option to log all the data to a text file.
One of the best things was that after buying this product I needed a customized functionality of its software in order to charge the battery, not only discharge it. I contacted the designer again and he added an extra mode for this (constant voltage inverted phase) and now it is possible to charge a Li-Ion battery with CC/CV method. So if you buy a cheap power supply "wall wart" type, you can easily build a battery charger for charging your battery! Great job!
I need to admit, that everything is open-hardware open source - you can access the C# code and do anything you want with it. Just like the designer states on the product page!

Shipping:
I was ordering MightyWatt from Czech Republic to Singapore. The whole ordering procedure and the shipment were much faster than I expected them to be, especially after experiences with other stores. After transaction, the designer customized the parameters and sent his product immediately. Everything was wrapped in a bubble wrap and ensured that it will arrive safe. I needed to split the invoice into two separate invoices and the designer replied immediately and split it for me.

Documentation:
Documentation for this product is written very clearly so everyone can understand it. There are steps how to assemble and calibrate MightyWatt, explanation how to work with the GUI and a detailed description how all of it works and how the data is being sent.
I am sure, that everyone can work with it, even someone who never had worked with hardware before.

Communication:
Communication with the designer was (and still is - even 2 months after buying his product!!!) just excellent! At the beginning he explained me everything what I wanted to know. His replies are long and full of details and he is making sure that I will understand everything well. I told him about my project and he shared with me his ideas even when the problem wasn't directly linked to his product. He was and still is very helpful. You really get the feeling that he cares about his customers. This is the first time when I met such seller, who makes so much effort and keeps in touch with his customer all the time.

MightyWatt is an excellent device, it works perfectly and I get absolutely no issues with it. The designer made a really huge effort with his product. He is very friendly and helpful and you can be sure, that he will help you with anything. If I have another similar project, I will buy MightyWatt again! I would be also interested in buying other products from this designer.

I am 100% satisfied with it and I am strongly recommending it!

I haven't fully tested it, but I have seen great accuracy after calibration. It's quite small and durable as well. The creator was quite helpful with my questions.