Why the Rasp­berry Pi 4 is the best choice for your dig­i­tal pic­ture frame project

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When I start­ed my first dig­i­tal pic­ture frame DIY project in 2014, I looked at many poten­tial com­put­er hard­ware solu­tions. But then I dis­cov­ered the Rasp­berry Pi, and have remained faith­ful to the plat­form until today.

In this post, I will tell you why I think it remains one of the best, if not the best, hard­ware solu­tion for a dig­i­tal pic­ture frame.

And with the intro­duc­tion of the Rasp­berry Pi 4 in June 2019, I won­der if any com­peti­tor will stand a chance to catch up any­time soon.

Small com­put­ers with huge poten­tial

The intro­duc­tion of mini­com­put­er boards has cre­at­ed many new appli­ca­tions for home and busi­ness.

Where­as a typ­i­cal Intel or AMD moth­er­board used to be rather large and demand­ed an ample pow­er sup­ply, the mod­ern sin­­gle-board ARM com­put­ers have a cred­it card sized form fac­tor and only require a small pow­er sup­ply.

This has made them ide­al for all sorts of do-it-your­­self projects for hob­by­ists, but also many com­mer­cial appli­ca­tions.

When I looked at pos­si­ble hard­ware options in 2014, I came up with these require­ments that still hold pre­cise­ly as they were today:

  • 0 dB noise. This means fan-less oper­a­tion and no oth­er mov­ing parts
  • HDMI video out­put capa­ble of dri­ving a 24 inch­es mon­i­tor with a res­o­lu­tion of 1920 x 1200 px and ide­al­ly 4k
  • A small form fac­tor, ide­al­ly cred­it card sized, which can be glued onto the back of a com­put­er dis­play and does not have a height exceed­ing 1.2 inches/3 cm
  • Pow­er con­sump­tion of few­er than 10 watts
  • Enough CPU (main proces­sor) and GPU (graph­ics) pow­er to run an advanced image view­er soft­ware

Regard­ing an oper­at­ing sys­tem, I quick­ly con­clud­ed that using a Microsoft Win­dows or Apple macOS oper­at­ing sys­tem would be overkill, so the choice for Lin­ux was an obvi­ous one.

Back then, the Rasp­berry Pi was the clear leader in mini­com­put­ers and the easy choice for my project. But in 2019, would I still rec­om­mend it as the best option?

Anoth­er fruit com­pa­ny con­quers the world

The Rasp­berry Pi is the brand name for a series of small sin­­gle-board com­put­ers devel­oped by a foun­da­tion in the UK. It intend­ed to pro­mote com­put­er sci­ence in schools and devel­op­ing coun­tries, and yes, they have reached that goal.

Last year over 20 mil­lion units of these cred­it card sized mini­com­put­ers were sold world­wide, and it trig­gered a whole gen­er­a­tion of young and old(er) peo­ple to learn about pro­gram­ming.

The Rasp­berry Pi may be a bit too slow for the use in an office, but it is great for tin­ker­ing with elec­tron­ics, exper­i­ment­ing, home automa­tion and gen­er­al­ly for projects called the Inter­net of Things (IoT). And it proved to be the per­fect plat­form for my dig­i­tal pic­ture frame project.

The tech­ni­cal data sheet sounds unim­pres­sive com­pared to Intel desk­top com­put­ers. Even the very lat­est mod­el of the Rasp­berry fam­i­ly, the Pi 4 only offers a rather mod­est CPU per­for­mance and mem­o­ry. But still, this is prob­a­bly more com­put­ing pow­er than Neil Arm­strong and his col­leagues had in their cap­sule for the first moon land­ing and plen­ty for a dig­i­tal pic­ture frame project.

What I like about it is the aver­age pow­er con­sump­tion of 3-4 watts which is prob­a­bly less than the stand­by pow­er of your tele­vi­sion. What­ev­er your motive may be to keep an eye on pow­er con­sump­tion, it just feels right to have a device that is very ener­gy effi­cient.

It only costs around US$35/€35 so exper­i­ment­ing with it is not a too expen­sive endeav­or to under­take. You need to add a pow­er sup­ply, a case and an SD card, so the final tab will be around 60 but still rea­son­able.

No great hard­ware can thrive with­out an ecosys­tem of soft­ware devel­op­ers, and this is where the Rasp­berry Pi shines excep­tion­al­ly bright. Mil­lions of enthu­si­as­tic fans result­ed in a vast num­ber of Rasp­berry Pi forums, clubs and devel­op­ers all around the world open­ly shar­ing their knowl­edge and find­ings to build yet anoth­er fan­tas­tic appli­ca­tion.

Even the mod­el from 2014, the Rasp­berry Pi 2 Mod­el B, had enough horse­pow­er for my dig­i­tal pic­ture frame. Over four years lat­er, the orig­i­nal pic­ture frame is still run­ning flaw­less­ly much to the delight of friends & fam­i­ly.

And unlike mobile phone oper­at­ing sys­tems which appear to get slow­er with every upgrade on the same hard­ware plat­form, this is not the case with Rasp­bian, the Rasp­berry Pi oper­at­ing sys­tem, a Debian deriv­a­tive (Lin­ux).

When I orig­i­nal­ly wrote this arti­cle, I stat­ed that there were a num­ber of hard­ware alter­na­tives to choose from and I men­tioned the ODROID-C2 as an exam­ple.

With the intro­duc­tion of the Rasp­berry Pi 4, I don't believe any­more that there are real alter­na­tives on the mar­ket. This is not just a func­tion of the much-improved hard­ware but of the ever increas­ing user com­mu­ni­ty around the Rasp­berry Pi.

Rasp­berry Pi 4

The lat­est Rasp­berry Pi 4 released in June 2019 is a huge upgrade to his pre­de­ces­sors. The most rel­e­vant improve­ment for home brew­ers of dig­i­tal pic­ture frames is obvi­ous­ly the abil­i­ty to dri­ve 4K mon­i­tors with a res­o­lu­tion of 3840 x 2160 px. Not only one but two!

The Rasp­berry Pi 4 Mod­el B

The CPU has received a slight bump to 1.5 GHz and Blue­tooth 5 is also part of the stan­dard pack­age. Plus you can now order the Rasp­berry Pi with up to 4 GB in RAM.

What I find a bit incon­ve­nient in the lat­est mod­els (start­ing with Rasp­berry Pi 3 B+), is that the SD card slot has no spring ejec­tion any­more. When I first got it, I thought that my mod­el was bro­ken and was ready to send it back. But after some inter­net research, I dis­cov­ered that this was the new tech­ni­cal design. My wor­ry that it could slide out is prob­a­bly unfound­ed in a dig­i­tal pic­ture frame appli­ca­tion, but I pre­fer tight con­nec­tors. Also, when your case is fas­tened onto a sur­face (in my case glued to the back of the mon­i­tor), you now have to take the moth­er­board out of the case to change the SD card. This was eas­i­er with pre­vi­ous mod­els although tak­ing the SD card out always required long fin­ger­nails or some­thing like a paper clip.

How­ev­er, to put this into per­spec­tive: The addi­tion of 4K is a big plus, the more RAM very love­ly and I only real­ly change the SD card dur­ing test­ing and set­ting up, so it's not much of a deal.

The size hasn't changed, and pow­er con­sump­tion with the dig­i­tal pic­ture frame appli­ca­tion run­ning remains at 3-4 watts, about 1 watt more than with the old­er mod­el 3 B+.

It still costs US$35/€35 plus pow­er sup­ply and SD card. The 2 GB and 4 GB mod­els cost about US$10 more each.

Long live the fruit com­pa­nies

The clone wars

The suc­cess of the Rasp­berry Pi has inspired many ven­dors to come up with their own brands. It's a bit like the clone wars of the 1980s after the launch of the IBM PC. There is a Banana Pi, an Orange Pi, a NanoPi and a few more with or with­out "Pi" in their name.

The word­ing "clone" is tech­ni­cal­ly not quite cor­rect as there is no direct com­pat­i­bil­i­ty with the hard­ware of the orig­i­nal Rasp­berry Pi.

So, if some­thing works on the Rasp­berry Pi, it is not guar­an­teed to work on the clone as dri­ver issues can intro­duce a lot of com­pli­ca­tions. "Pi" ven­dors try to ben­e­fit from the pos­i­tive image of the Rasp­berry Pi series, but in real­i­ty, the clone may have lit­tle to do with the orig­i­nal.

None of them can beat the Rasp­berry Pi on price. Most of them come with a more per­for­mant CPU, but this is not rel­e­vant for a dig­i­tal pic­ture frame appli­ca­tion. My aver­age CPU load on the Rasp­berry Pi 4 is less than 5%, so there is just no need for more horse­pow­er.

The dif­fer­ence regard­ing soft­ware and com­mu­ni­ty sup­port means clones are only a suit­able sub­sti­tute in some cas­es and you may end up spend­ing many hours fix­ing bugs that you don't see on a Rasp­berry Pi.

All the tuto­ri­als on this web­site are work­ing on a Rasp­berry Pi com­put­er. There is no guar­an­tee that this will work on any of the oth­er Pis.

I fail to see a real advan­tage in rec­om­mend­ing the Pi clones. They are often more expen­sive and don't nec­es­sar­i­ly have any­thing that would make a real dif­fer­ence for this use case.

But what about Intel NUC and sim­i­lar­ly sized mini­com­put­ers? The rea­son why I have not includ­ed them in this post is that their price is about ten times that of the Rasp­berry Pi and they have much larg­er phys­i­cal dimen­sions and the space behind the mon­i­tor is very lim­it­ed.

Intro­duc­ing 4K

When I orig­i­nal­ly wrote this arti­cle, the most up-to-date mod­el was the Rasp­berry Pi 3 B+. And what this mod­el lacked bad­ly was sup­port for 4K mon­i­tors.

In June 2019 Christ­mas came ear­ly with the intro­duc­tion of the Rasp­berry Pi 4 which not only fea­tured one 4K HDMI out­put but two! You can now dri­ve screens with a res­o­lu­tion of 3840 x 2160 px allow­ing to bring utmost sharp­ness to even large dig­i­tal pic­ture frames.

This is where oth­er ARM-based mini­com­put­ers had been able to offer a real advan­tage. At least in the­o­ry, because I am hear­ing about many dri­ver issues that make it dif­fi­cult to exploit this advan­tage. But this advan­tage is no more.

The 4K road ahead

I am cur­rent­ly prepar­ing a tuto­r­i­al on how to make a great dig­i­tal pic­ture frame with out­stand­ing image tran­si­tions in 4K.

One issue is keep­ing me from build­ing it today.

It is the lack of a decent 27 or 30 inch­es high 4K mon­i­tor with an aspect ratio of 16:10. If they exist, please send me an email.

I haven't been able to find them except for some extreme­ly bulky and expen­sive mod­els for med­ical appli­ca­tions. 16:10 is essen­tial to avoid crop­ping too much from a stan­dard 3:2 cam­era pho­to.

Con­clu­sion

If you want to build a dig­i­tal pic­ture frame, pick a Rasp­berry Pi as your com­put­ing hard­ware of choice. Any Rasp­berry Pi start­ing from 2 Mod­el B+ will work. If you want 4K capa­bil­i­ty, get the Rasp­berry Pi 4.

CPU per­for­mance doesn't mat­ter for the dig­i­tal pic­ture frame use case. What mat­ters is com­pat­i­bil­i­ty, reli­a­bil­i­ty and clear instruc­tions that you can fol­low.

The Rasp­berry Pi has the most sub­stan­tial fol­low­ing of any ARM sin­­gle-board com­put­er. The amount of guides, tuto­ri­als, and soft­ware avail­able for the Rasp­berry Pi is unmatched by any oth­er board.

All the DIY tuto­ri­als on this site are cur­rent­ly for the Rasp­berry Pi. So if you are inter­est­ed in pro­duc­ing a result quick­ly and reli­ably, this is the road to take.