HackSpace magazine

Meet the Maker: Timon Skerutsch

By Andrew Gregory. Posted

The Arduino and its ecosystem are ubiquitous in hardware development, thanks to its open architecture, cheapness of price, and abundance of ports; the Raspberry Pi is ubiquitous in computing, thanks again to its low price, the exposed GPIO pins, and its free Linux operating system. Wouldn’t it be great if you could combine them, taking a Raspberry Pi Compute Module and adding some extras to make it slot more easily into hardware development, just like the Arduino? 

That’s the idea behind the Piunora. We featured this little board when it was in its crowdfunding stage and, now it’s being manufactured and distributed, we thought we’d check in with its maker, Timon Skerutsch, to find out how the journey from crowdfunding to product has been going. Spoiler alert – it’s been a lot of hard work…

“Back in December 2020, I posted on Twitter a prototype of Piunora. I had no idea at that point that I’d turn it into a product; it was just that the Raspberry Pi Compute Module was always something that interested me. I made some hacky carriers for the older modules and [was] just playing around. 

“The initial idea came from Scott Shawcroft at Adafruit, who works on CircuitPython. He was like, somebody should just make Compute Module 4, but in an Arduino form factor. And that stuck with me. I thought, I can do that, it’s not too hard. 

“Over a weekend I threw out that first design, and people were, like, really into it. I’d always been thinking about starting a side business – before that I was working on this Linux tablet thing – and manufacturing process-wise, it’s fairly easy to make these kind of boards: it’s just a PCB. It’s a good startup product, you know.

“I started to set up a company, which was a fair bit of work, at least in Germany, all of the paperwork. And then I got in contact with Crowd Supply. Helen Leigh there, she’s a friend of mine, and she kind of talked me into that. I was thinking, you know, it’s not so expensive, I could get the funds together from my own money. But it’s less risk if I have someone else’s money for that, and anyway, a [crowdfunding campaign] helps you to gauge demand for a product. 

“And then it was three months of work, of preparation for the campaign. The trickiest part was gauging pricing – you have to give people a price without actually knowing what the production will cost. There are so many factors – in four months’ time pricing will be different, components might not be available. The shortage was already beginning, so there was pressure on to lock in a price for components before they went up. There were several weeks of back and forth with my manufacturer, building up that partnership more. And then making all of the media content for the campaign and PR stuff – that was a ton of work. I actually took a vacation for that – I took three weeks off my day job. 

“So, that definitely was a full-time job, for at least a month, to do all of the writing and comparison stuff   that you have to make: how am I different to others? And what do I offer you?

“The video alone took two and half weeks, and that’s just a 1-minute, 20-second teaser video. For anyone who’s thinking of crowdfunding a product launch, the best thing you can do is have people who you can work with, who can support you – don’t do everything by yourself.

“I think at the end of the crowdfunding, I’d reached 120%,130% of the initial target. I’d hoped for a little bit more, but I got funded, which is what counts at the end of the day. After that, I started beta testing with people; I made the first initial run with a manufacturer to test. First of all, you have to test the manufacturing: is everything the way I want it to be? Ordering PCBs and soldering them yourself is different to instructing someone else to produce something. There’s a lot of little details there that you have to get right. 

“And, in between all of that, I was constantly fiddling with the design. The first prototype was like 90% feature complete. But the last 10% of UI UX: what should the legends look like?; what should I put there? Like, what information is important? Where should I place connectors; where are they most accessible? That’s a huge usability thing. If you want to make it a good product – one that people actually use, rather than buy and stick in a drawer somewhere – that takes quite a lot of time. So, I would say that the optimisation part took me another six weeks’ worth of work, drawn out over about five months. 

“Shortly after the campaign, I bought all of the components immediately, which was kind of a risk because the design wasn’t 100% finalised. But, you know, the shortage was hitting, and everything I needed was depleting in stock rapidly. So I had to buy it, even if I didn’t know for sure I’d be using it. And the other thing was that I didn’t even have the funds at that point. I had to buy components with my own money – luckily I had enough savings to be able to do that. 

“In other circumstances I would have probably not needed to do that but, because of the circumstances, I just needed to do it immediately. That’s why I put out the money – to secure the components. Everything else, I paid afterwards, like PCBs and manufacturing costs. 

“There was a lot of logistical back and forth, a lot of corresponding with people; that was the biggest strain, because I had a day job and, on top of that, there was this constant list of five or six background tasks. Even if it was just an email that I had to send, it was constantly on my mind. Because if you don’t do anything, it’s not getting done, because you’re the only person doing it – that’s another reason to have a team member, someone to help you. 

“There was a delay in production with a high-density connector for the Compute Module; that was another three or four weeks, because the manufacturer was not confident to just use an optical inspection [an automatic optical inspection, where solder joints are inspected visually]. It was so fine-pitched that it was hitting the limits of their machines so, at the last minute, I had to make this electrical tester that dropped in in place of the Compute Module and checked the connections electrically. For more complex products, the testing process can sometimes exceed the engineering time of the actual product. It’s quite a task to make these testers, and I was hoping I wouldn’t have to do that, because it’s a simplistic product without [many] active components. I didn’t anticipate that.

“I also didn’t realise that I needed CE certification to sell in Europe, because they removed some exceptions in recent years that they had in place before. So, I also had to rush to get CE certified. Yeah, there’s so much documentation you have to write for all of these things. If you do it all yourself, build things yourself, test things yourself, you don’t have to communicate anything, you can just do it because you know what to do. But, if you have to educate a whole other team on what’s in your head and what to do   and it’s just you know… even down to making designs for the little labels that go on the box, designing the box, specifying how it should be packaged. You have to tell people to add a length of adhesive tape for sealing the box. It’s so many little things that add up to a ton of work, really. Buying stickers – it’s not something you think of when you’re making electronics, but it’s part of the thing.

The Piunora

“I made the Piunora because there wasn’t anything out there that was Linux, catering to electronics prototyping specifically. The Raspberry Pi, for example, is a computer. You can do electronics with it, but it’s not made for that purpose. It’s got this [unlabelled] 40-pin header interface, you know, you have to count pins to find the right spot, and there are a lot of little details that add up to a wall that you have to go over for starting a prototype.

“With a Piunora, you plug it into a computer, it’s easy to hook up the wires; there’s silkscreen [labelling] so you know what everything is. You have analogue interfaces, which the Raspberry Pi doesn’t have, you have some buttons and some inputs and outputs that you don’t have to add when you’re prototyping; you can just get on with it. 

“I’ve added a NeoPixel LED, an analogue input, an ADC. One thing that was very important for me because it’s so big in the electronics space, is the Qwiic connector for I2C, which enables you to hook up these little boards that SparkFun and Adafruit make… It’s just a lot of these small little things that are nice to have when you’re doing electronics prototyping. I’m working on something at the moment, and I have my accelerometer connected. I don’t have to find out where the I2C ports are: it’s just plug and play – basic. Load up the Python driver and that’s it. It’s also important to me that all of the pins are labelled, at least important ones. And one other thing the Raspberry Pi doesn’t have is that it doesn’t break out the PCI Express ports; being able to add an SSD, or even a SIM card connector, is useful in some sensor deployment applications.  

“I’ve not completely finished my vision for USB mass storage on the Piunora, but it’s kind of there. And you do have that on the Raspberry Pi 4. But the issue is the Raspberry Pi 4 has much higher base power consumption because more peripherals are present. With Piunora, it’s about 560 milliamps at peak, if you don’t have anything connected. That means you can connect it to a computer via a USB 3.0 cable (a USB 3.0 port can do 900 milliamps). And, if you connect it to the USB-C port, it can then be a USB device, which is where I always wanted it to be. It’s always felt like, for prototyping, it’s kind of tricky to have to connect to WiFi, or have a screen plus keyboard, and find out the IP address, SSH into it, enable SSH… it’s like a process. I wanted [it] more like Arduino: plug it in, it boots, and it becomes accessible via a serial port. And that’s something that the Raspberry Pi can’t do. 

“At the moment, I can kind of do Arduino-style – I can SSH in, or I can sit at a porch terminal kind of broke with it. But, if you’ve worked with CircuitPython before, when you connect, it becomes a mass storage device where you just edit the code directly on the microcontroller.

“That’s very specific to CircuitPython, and I’m a huge fan of that. You just plug it in. It’s like a USB stick that pops up and there’s a code.py file. OK, and you just write your code and press Save. And then you know, the microcontroller reloads and has the new code running, which is super-cool for rapid prototyping. I wanted to also have mass storage, so you can drop files on it and have them transferred to the active file system, and then be able to work with them without having to do SFTP or something: just like drag and drop files around, that kind of workflow. I had it working as like a proof of concept, but I want to get it more robust.

“It’s still early days, but I’ve had a bit of feedback already from people using the Piunora. It’s always kind of hard, because a lot of people buy it and do things but they never get back to you about it. Somebody connected it to a kind of Motorola laptop – Motorola made this laptop without any brains with it, where you can plug in your phone and then it becomes like a laptop – just HDMI and USB input. And people hacked that together like a Raspberry Pi and it had this huge clunky thing on the back. They have apparently [got] a similar device, and they made a laptop out of it, which is kind of cool because everything is on one side. So, you can just make this whole pluggy thing with it, because all the connectors are on the front. 

“I can’t tell you the name, but there is a large research institute using them for medical research, which I never expected to happen.

“I saw a lot of IC companies order it, so I assume a lot of people use it for testing jigs, or something like that. FTDI bought a lot of them. I’ve no idea what they exactly do – I guess some lab applications. 

“One reason why I want to do some more tutorials, or publish projects with the Piunora, is to give people something to work off, because I feel a lot of people get started by following Adafruit guides or something similar. I packed a ton of features into the Piunora, and I know what you can do with it. But I think it’s communication work that I still have to do to – to show people what exactly you can do with it, and get the imagination flowing.

“One thing that I’ve done this year is make a Piunora operating system image, which is a modified Raspberry Pi OS image that sets everything up for you, so you don’t have to fiddle around with scripts and stuff – everything’s ready to go. 

“I think it’s easy to get started right away at the moment, but I want to show what things you can combine. You can, I don’t know, control NeoPixels from a browser, for example. I want to take the powerful Linux computer that the Raspberry Pi 4 is and show people what you can do with it when you combine it with electronics. 

“That’s why I made Piunora – to make that hurdle a bit easier.”

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