Meeting with Nick Marchuk, a professor at a Northwestern University in Illinois, found that there weren’t enough of the expensive desktop tools available for all students to experiment with their circuits. With his co-creator, David Meyer, they decided to do something about it and created nScope so that everyone could have access and for less than the cost of a textbook. Our interview discusses why exactly they needed a something like the nScope, the development process they went through, and the capabilities of their low-cost tool. For more info about their tool, go to their website - http://www.nscope.org/.
Nick: I’m with nScope. It's a bread-boardable USB oscilloscope, power supply and function generator. It’s a tool that we give to students so that they can learn how to build a circuit, and then debug it. Because usually the first time you build it doesn't work. So you need to be able to see why it's not working and try to fix it.
Josh: Could you tell me a little bit more about the exact functionality here. You say, a power supply, analog-out and analog-in?
Nick: So we get ± five volts up to 200 milliamps. That's enough to power op-amps and LEDs, but not quite enough to power a motor. It monitors the power, so if you short it, it will turn itself off and save your computer. So that's always nice. We have four analog inputs, so you can see four different channels simultaneously. We have two analog out and two PWM out and then you could use those to be inputs to your circuit and then see what your circuit does to them and feed them back in again.
Josh: Excellent. Now this is interfaced with a computer, would you mind demonstrating the program?
Nick: Yeah, so I just have a laptop here (the software runs on Windows, Linux and Mac). We get power over USB and then we use the screen for data. So on this board, I've got a couple of circuits. One is a temperature sensor and that's the yellow line. So if I warm up one of the components, the yellow line goes up to show that the voltage is increased and if I touch the other component it comes back down. And it's nice and noisy because the the sensor has a gain of about 100. So the little bit of noise gets amplified as well as the signal. And so when you start to build circuits like this you you start to get familiar with “Oh, you know, the signal is too small", that's why I built the circuit to amplify, "and now there's noise", so I should probably build a filter. And you get a very kind of hands on intuitive feeling for why we build circuits and how we debug them.
Josh: Excellent. And is that a sine wave I see down there? Is that one of the outputs?
Nick: Yeah, that's one of the outputs. We can set it to be bipolar, meaning positive/negative, or unipolar, all positive. We can change the frequency and the amplitude. And that might be something you feed into a speaker, or you feed into a motor and make the motor move in that way.
Josh: And so what was the inspiration? Why did you do this project in the first place?
Nick: Yeah, so I was a graduate student in mechanical engineering. And we have a class for mechanical engineers learning how to build electronics, and it's usually around 100 students every year, and the lab had eight benches. So you'd have like five people sitting at a bench and one person doing all the work and the rest just watching. And we decided it was a bad experience. So we said let's flip this class (at the time it was very popular to flip classes). And rather than a textbook, the students would buy a kit. And they would get to watch videos online to learn how to build. And then they'd use their kit at home and in class to do the learning. And we were buying kits from other suppliers and mixing and matching and nothing was working the way we wanted it to. So we said, "you know what, let's just make our own." And for five years, I designed a board and we used it for a year and then I fixed it, and we use it again. And and after five years, the hardware is done and some other schools contacted us saying, "hey, we heard that you're doing this thing, can we buy it?" And it was a sign to us like, "hey, let's, let's try a company." We put it on Kickstarter, and had a lot of success on Kickstarter. We shipped 2,300 units over three months. And then that seed money has allowed us to start a company. We sell these on Amazon and it's been a really fun experience to live that startup culture and get the product into the hands of my kids for education and there's not much stress on us because we still have our full time jobs. We're learning a lot about how to run a business and how to do hardware and how to support the software so it's been a lot of fun.