Some electronics come as a single PCB. They have CPU and everything on just one board.

Other electronics are a shield for an Arduino. So these are always two boards. The Arduino and the other PCB.

You probably don't want to exchange the Arduino unless it is broken. Does it break that often or are the two boards just the predecessors of the one board solution?

What are the benefits/downsides to having one/two boards?

  • $\begingroup$ For folks who do a lot with Arduino, shields/hats/wings/whatever are freshman-year parts, 80% solutions for low-experience makers who want to say "I built this line-follower/temp-logger/smartcam/printer/etc" after snapping together 2 parts and flashing the demo project code. Since any extra pins are typically blocked by the shield, they are not even very expandable or customizable. Most would be better off with a single board; turn-key code for noobs, and a slightly more complex than a plain uno board procedure for vets to code with C++. $\endgroup$
    – dandavis
    Dec 18, 2020 at 22:42

3 Answers 3


Many 3d printer motherboards are based on Arduino/Atmega microcontroller and just add some stepper motor drivers, MOSFETs and such in a single board. That explains why you use the Arduino IDE to update or modify their firmware.

Now why you would want to use an Arduino + an Arduino shield board like RAMPS? Well if you're not good at electronics, are happy with the cost of your own board, don't care much about upgrades/modding beyond what is possible with your board, maybe you shouldn't, it might be overwhelming.

There are several advantages with using Arduino with a shield for your 3d printer, "two boards are not just the predecessors of the one board solution", no.

1) It is moddable/exandable/upgradable/has replacable parts. If your printer came with its own motherboard that doesn't have additional or enough pins to add more fans, enclosure lights, a second extruder, an LCD and you want to, it sucks. RAMPS can do that, it has plenty of extra pins. It is upgradable. You want to replace the stepper drivers with a new one? Or you accidentally damaged the one you have? Fear not, you can just replace that instead of the whole motherboard. Think if it like other motherboards being PCs on which you can't change the CPU, RAM and GPU.

2) It is here for a long time, you will be able to acquire one for a long time. There isn't just one company making RAMPS or similar sheilds. Sometimes 3d printing companies go out of business or stop producing your particular motherboard. RAMPS is likely here to stay. Because Arduino is very likely here to stay.

3) As said above, not just one company owns or makes RAMPS or other Arduino shields. Besides the possibility of your motherboard not being produced anymore, there's also the advantage of not being at the mercy of one companies pricing and shipping policies. This is true for some other boards as well though.

4) It is possibly cheaper than what have you. I don't want to post a link, but one company right now is selling their derivative of Printrboard for like $180. Check the cost of Arduino Mega, stepper drivers and a RAMPS board yourself, quite a difference. That said, there are some boards which are close in price.

5) It's an Arduino. Why is this a good thing by itself? Because many people who have a 3d printer are tinkerers/makers and they already use Arduino for other projects. It is open source with a rich library to control many things. The modding and upgrades for your 3d printer which can be done with Arduino is another level higher. Or it can be a good learning experience for your future Arduino projects. If on the other hand you already use Arduino and are experienced with it, you might use it just because you know how to control it/fix it better than some specialized board you haven't seen before. Plus for a guy like you your 3d printer's motherboard will be an "off-the-shelf" part, that's nice, right?

Video on RAMPS: https://www.youtube.com/watch?v=FYJn6FuWOv4


There isn't really a big advantage to one solution or the other. The approach of having separate boards means it is more modular and broken parts can be replaced more easily, but electronics don't break on their own: it is almost always user error. If you are even a tiny bit careful when assembling your electronics, you won't ever have anything break and the advantage of having modular electronics is moot. On the other hand, there's no disadvantage to using modular electronics either.

Of course, another advantage of modular electronics is that you can upgrade separate components (for instance, swap in better stepper drivers). The value of this advantage depends on whether you eventually want to upgrade.

  • $\begingroup$ Agree, although even the wisest of us do some stupid things sometimes. I've fried the some components on some PCBs (one being a Printrboard) just because I placed the probes of a voltmeter in the wrong locations. Also, from the answer it seems like you'll want to replace some components only when you damage them. But another case is when you want to upgrde them. Still, valid point. $\endgroup$
    – Leo Ervin
    Feb 7, 2016 at 10:34
  • $\begingroup$ If I look from a different angle. A single board having less modules, therefore needs less assembling and therefore smaller risk of accidentally breaking the electronics? $\endgroup$ Feb 7, 2016 at 12:35
  • $\begingroup$ Nah. The assembling consist of just plugging a female socket to a male header or vice-versa. I have never heard of anyone breaking either when connecting them, they are sturdy. And you can't connect wrong component to the wrong place because their connectors are positioned physically differently, you can tell by just looking. As for the few power cables which have to be screwed in place, well if you're having trouble getting them right than like I said you don't know much about electronics and are better off with a single board controller. $\endgroup$
    – Leo Ervin
    Feb 7, 2016 at 15:38

There is an advantage to the one who builds the shield: They don't have to design the circuit that is on the Arduino (main board), possibly even including Wifi or USB communication. The components on board are more expensive in small volumes, so the ready made boards are even competitive in price. Developers get a proven and well known board, with perfect support in software toolchains. Depending on the solution, they might even have less trouble with certification, as the high frequency components are already known. So, they only have to design the shield, holding some motor controllers, sensors or similar.

This makes it possible to produce small amounts of units very fast, which is also a benefit for the end users / end customers. It makes niche solutions possible at lower cost. Being able (if at all) to swap out a single component is likely not a real benefit, except if you enjoy taking your electronics apart.


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