You Can Build This Raspberry Pi-Powered, 4G Linux Phone

Raspberry Pi
(Image credit: Evan Robinson)

It's easy to build your own desktop PC but, if you want a phone, you usually have to settle for a sealed box that's made by one of a handful of large corporations. Maker Evan Robison wants to change all that as he posted instructions for an open-source, Raspberry Pi-powered called OURPhone with the acronym OURS standing for Open-source, Upgradable, Repairable Smartphone. 

According to Robinson, the idea was to create a smartphone alternative for people looking to control their privacy. He also wanted to make a smartphone that could be easily modified and repaired, so an open-source solution was the perfect fit. The OURphone project has quite a few specs that you’ll find on many smartphones including 4G LTE internet support, GPS support, Bluetooth and WiFi capability, as well as basic phone operations like the ability to call, text and save contacts in an address book.

However, instead of running on Android or iOS, the phone uses Raspberry Pi OS, the Linux-based native operating system for Raspberry Pis. This means that you have very fine control over what software you run on it, but the UI (as pictured) is not particularly touch or phone friendly. You can find all of the code used in the project (as well as detailed instructions) at GitHub.

In his build guide, Robinson is using a Raspberry Pi 3 B+ but there’s no reason you couldn’t upgrade it to a Pi 4. It’s accompanied by a 4G HAT with GSM and GPS antennas. It has a Waveshare touchscreen for video output and user input. A camera can be attached but it isn’t necessary for the build. A pair of headphones with a built-in microphone is used for call support. To keep the unit mobile, it operates off of a couple of 18650 batteries. 

The housing, ade out of 3mm MDF board, is a bit bulky but necessary to contain all of the hardware. It’s laser cut with port access made available all around the edges.

There are already plans in the works to add more features like a Pi upgrade, a capacitive touch screen, and a monitoring system to check the battery level. Robinson asks that anyone interested feel free to improve upon the design and share any changes they implement. He’s also made himself available at LinkedIn for anyone that has questions along the way.

If you want to get a closer look at this Raspberry Pi project, check out the official project page over at GitHub and be sure to follow Evan Robinson for future projects as well as any updates on this one.

Ash Hill
Contributing Writer

Ash Hill is a contributing writer for Tom's Hardware with a wealth of experience in the hobby electronics, 3D printing and PCs. She manages the Pi projects of the month and much of our daily Raspberry Pi reporting while also finding the best coupons and deals on all tech.

  • ezst036
    I like this a lot. Hopefully some future Raspberry Pi Pico or Pi Zero that is fast enough to run a whole operating system could make this physically smaller and thus more manageable. The best part I think is that phone calls across a normal 4G network can be made right from the O.S.

    I'm going to need a new phone soon. I do not want some retail junk with some Android that is impossible to remove so Google can continue spying.
    Reply
  • zackbacher
    Really wish we could start getting content for other sbc’s because raspberry is running stale hardware and currently being scalped for 5x its initial price over the company is heading downhill
    Reply
  • bigbones
    If you lookup what phones the most rich and powerful people use, you will soon realize that everyone is stuck with garbage phones. I truly wish there was a better alternative to android or iOS. And you can't give it up either, you need to be able to use banking apps, etc. Which I doubt work on this.
    Reply
  • Nazosan
    An interesting idea, but I perceive a HUGE problem right off the bat: the cluster-F that is VoLTE. It should have been standardized (I think this is the FCC's domain? Not sure) and made available to all devices in a minimal form, but it's not. It was deemed "good enough" for all 4G phones to fall back to 3G for voice services. VoLTE was treated as a "luxury feature." Now that 3G services are shut down, that "luxury feature" is now as basic as it gets. Problem is, since service providers were allowed to treat VoLTE as a luxury feature not available to everything, they turned it into a complete mess of licenses and checks. Since they wanted to be sneaky about it, they charge companies the licenses, not users. You can't opt in at a user level. This means they had to implement a system of license checks that basically check your device against whitelists of which companies have paid for the "extra feature" for their specific phones to promise better voice quality (aka just using 4G at all for voice.) Needless to say, any device like this will not be in that whitelist. Along with probably exponentially more devices off the list than actually are on it. In other words, to get voice on almost any real service you're probably going to have to pay for data and also pay for some VoIP service such as Google Voice or whatever.

    I love the idea of it. Honestly, we need more fully open phone devices. In fact, it's really stupid we don't have more openness even in Android phones as it is. Many are well known and well supported hardware, but just don't have sufficient interest among those who can do lots of stuff with them. Even among those who do though, driver support can be an issue. We need an OEM to release one that's very open and not try to turn it super commercial (like a certain ONE did...) But also projects to get a good Linux or similar port going need to take off.

    Actually, I feel like for a while now it has been time to move from super limited, super embedded operating systems where just running apps at all basically wrecks battery life and murders the CPU. All these systems we're using now were made in the early 2000s for very weak devices that barely could even run an OS. The way apps actually act is very limited out of necessity with simplistic methods and APIs. Modern apps have had to build up on top of things built up on top of other things and it actually has reached the point that resources are being wasted in even simple operations. Not to mention just how limited things are as a whole. Modern smartphones are sort of already mini computers at this point with almost as much power as a very weak laptop. We should utilize that.

    ezst036 said:
    I like this a lot. Hopefully some future Raspberry Pi Pico or Pi Zero that is fast enough to run a whole operating system could make this physically smaller and thus more manageable. The best part I think is that phone calls across a normal 4G network can be made right from the O.S.

    I'm going to need a new phone soon. I do not want some retail junk with some Android that is impossible to remove so Google can continue spying.
    I'm a bit confused on the first part. Raspberry Pi Zero can run a real Linux. The Pico is actually the exception to the entire line in that it's basically an Arduino rather than a true Raspberry Pi. I mean, to be clear, yes, the RPi Zero is very weak hardware-wise. Though that would possibly be an advantage in regards to a minimalist device like a phone should be. But it does run Linux and could absolutely do this, albeit possibly with annoyances like sound skips or drops or etc when overloaded (you'd definitely have to keep it minimal...)

    Google isn't the one you truly need to worry about spying with service provider ROMs. I've found all sorts of crap on mine from companies that even straight up admit they abuse people's info like "Meta" (Facebook) app and messenger on mine. As much as people don't like that Google has information collection at all, at least they do actually anonymize/etc and generally if you just follow the right methods you can actually pretty much block or control anything that matters in that regard. The real problem is that most people just don't. Ultimately the key here is to take control of your device. Of course, as you say, this still isn't 100% possible with a locked down service provider phone.

    That said, look into LineageOS. Combined with microG to provide some basic alternatives. I think you'll find that you're going to be fairly limited in what you can do on a smartphone in the ways that most people actually use their smartphones (assistants are probably not going to work at all for example) when you go into tinfoil hat territory, but it is possible if you really must. The number of devices that have good LineageOS support is relatively small, so check their wiki thoroughly. As I said above, 4G VoLTE is an issue, so you want to stick to 5G supported devices (luckily 5G is somewhat standard-ish. At least real 5G is.)

    My suggestion, though, is to strike a good balance. Get a good phone that is supported well by LineageOS with active maintainers (something relatively mainline like, ironically, the Google Pixel phones for instance.) Take off the tinfoil hat, but don't give up privacy altogether either. Take control of your data and your apps using the existing methods already built in that no one really uses. Also, when an app pops up asking for permission to access something, think before hitting allow (but also think before hitting deny. You should understand how permissions work. For instance, things like bluetooth/wifi control are within "location access" because an app could figure out your location simply by having control access to those features, but this, on the surface, sounds unintuitive or even incorrect until you realize the why behind it. You don't have to know all the whys, just the whats. Some apps will legitimately need such things, some will not.) Strike the right balance of things and you'll have a device you control with all the privacy that anyone who isn't a secret agent spy acting in a hostile country actually needs. (And if you are a secret agent, you need to stop posting on forums like these!)

    zackbacher said:
    Really wish we could start getting content for other sbc’s because raspberry is running stale hardware and currently being scalped for 5x its initial price over the company is heading downhill
    Agreed 100%. Although the chip shortage kind of hit everyone, not just RPi, it suffered the worst because of its scale. That said, we need other devices for far more important reasons like better hardware capabilities for instance. The problem is none of the others are making the effort to make their devices as big, "standardized" so to speak, as open, and, most importantly, to bring in the third party support. Ultimately it's an issue largely more of marketing than anything else. For everyone else, SBCs seem to be a niche thing they barely bother with. Some make really good SBCs but just don't put in the effort to bring in that support. ODROID has been close a few times, but then they run into the probably even bigger problem that such devices simply aren't open enough usually. The biggest problem there, of course, tends to be that GPUs are a hot mess as a whole. Somehow we, as consumers, allowed GPU designers to make them so super proprietary and locked down that there is more undocumented about the average GPU than even is officially documented. This makes it super hard for devs to write anything that involves the GPU in any more than a cursory fashion. (And even if your average app designer doesn't have to worry about it since they have APIs to use instead, the fundamental problem is at the baseline the drivers/etc those APIs utilize are lacking.) RPi kind of fixed this by having an open GPU -- at the cost of it being a really horrible GPU relatively speaking. I'm not 100% clear on what happened regarding the GPU in the RPi4 though. I think it was supposed to be better, but still really hard to support. (All I know is I did put a RPi4 to use as a "desktop" of sorts and it still is very weak on many tasks such as video watching on the Web.)

    Honestly, what I really wish had happened was more done around the Intel Atom SoCs. There was a lot of potential with x86 chips using Intel GPUs (well known even if still proprietary and locked down) in regards to being extremely accessible to developers. ARM has traditionally been better for low power usage and such, but the Atom SoCs were actually surprisingly decent in that regard too. I feel a lot of potential has been lost by the series basically more or less dying out without truly being utilized. For a short while there was an "Atomic Pi" board which had a semi-decent Atom, but it was never meant for real consumer access (it was designed to go into robots. Large robots I guess because it was huge. The board also had a horrible design for general embedded applications and frankly would have been worse for robots than it should have been.) It never went to major large scale production and I assume all the hardware is sold out by now. There were actually a bunch of little Atom-based "sticks" that were the size of a Roku or etc, plugging into an HDMI port though, so I've seen first-hand how tiny these things can really get and still be surprisingly capable. One of these given a RPi Zero-like board's interfaces would have had enormous potential. I have seen these chips utilized in devices like the GPD Win handheld gaming computers though which weren't too bad overall (limited more by general qualitative choices like a low grade battery that expands, bad cooling design, etc.)

    I feel like SBCs as a whole just aren't given the love they truly deserve. There is just so much potential not being realized.
    bigbones said:
    If you lookup what phones the most rich and powerful people use, you will soon realize that everyone is stuck with garbage phones. I truly wish there was a better alternative to android or iOS. And you can't give it up either, you need to be able to use banking apps, etc. Which I doubt work on this.
    I seem to recall a certain high profile figure being stupidly stubborn for a long time about using a really ancient phone with known major exploits unpatched by the manufacturer. Said person eventually got something newer (naturally an Apple because thinking be hard and easier let others think -- especially for said person) but it is a major problem in general. Especially for government figures (and doubly especially for those who insist on bringing said phone into classified meetings.) Actually, the security thing is a mess as a whole. (Apple had clout early on when they could put their foot down and actually get their way and they had the need to control everything to be what they are, but while Google had the clout, they chose to keep their stuff pretty open and now we have a mess where modern Android phones can't get security updates because the whole system relies on everyone but Google to actually get security fixes out there and even big companies like Samsung are pretty haphazard about getting those patches out there and through stubborn service providers that delay updates to "approve" them and add in their own stock apps and such. Sometimes "open" has its disadvantages...)
    Reply
  • ezst036
    bigbones said:
    And you can't give it up either

    Yeah you can.

    You just choose not to.

    This. ... is why we can't get past an Android/Google and Microsoft and Apple world. The problem is in our mirrors.
    Reply
  • ezst036
    Nazosan said:
    I'm a bit confused on the first part. Raspberry Pi Zero can run a real Linux
    Ideally it would be a Pico. Not a Zero. I only added that in because I realized after a minute how underpowered the Picos are. But a Zero is still logically too (physically) big. I have not owned a Zero myself, but I do have a Pi (3), they are not ready for daily use. Even as a phone. Too underpowered.

    My main phone is currently powered by Lineage OS. But I think it's time for me to move to something like UBPorts or a PinePhone.
    Reply
  • usertests
    ezst036 said:
    I like this a lot. Hopefully some future Raspberry Pi Pico or Pi Zero that is fast enough to run a whole operating system could make this physically smaller and thus more manageable. The best part I think is that phone calls across a normal 4G network can be made right from the O.S.

    I'm going to need a new phone soon. I do not want some retail junk with some Android that is impossible to remove so Google can continue spying.
    Raspberry Pi 4 Compute Module 4 would be a better choice than Raspberry Pi 3 B+.

    Pi Zero 2 W is basically a Pi 3 in a smaller form factor, and might be enough performance.

    But there are better options. Maybe PinePhone, or just unGoogle a cheap/used smartphone using LineageOS (formerly CyanogenMod).
    Reply