Notes on a Banana

I have had a Banana Pi M2 Zero hanging around for a few years now and never really got around to using it much (or mentioning it at all), but in this time of supply chain shortages and when are effectively made of unobtainium, I thought it was worthwhile writing a review of sorts.

Hardware

I don't think we need a real banana for scale.

I’m not going to waste time poring over specs–the reason I got this board in the first place was that it has a quad-core CPU and can run armv7 binaries, something that the original Pi Zero couldn’t. It still has only 512MB of RAM and no built-in storage, but at the time it was a pretty decent upgrade in terms of performance.

Right now, it looks like an almost direct replacement for a , although there are some physical differences and it does not fit all cases. If, like me, you like the Flirc cases, mind that the heatsink nubs are in the wrong place and it will require some care to actually close the case shut.

And you will need to manage the temperature on it. One of the reasons I put it aside right after buying it was that it got a bit too warm for my taste, although that seems to have been fixed by putting it into the Flirc case.

Software

The biggest difference for me, however, has been the software. Even if you’re willing to turning a blind eye to the manufacturer thinking that downloading firmware images off Google Drive is acceptable (which is how I got the initial Linux images for it), the reason I left it in a drawer for nearly two years was that the software support was nothing short of horrible.

For instance, none of the (barely) documented ways to use GPIO pins worked (and, obviously, a lot of hardware like LCD displays and whatnot was thus completely unsupported), I could not get Wi-Fi to work reliably, and I needed to manually fix package sources to get it to update.

Fast forward until a couple of months ago, and I finally found a third-party OS I could run on it and now have a reasonably stable version of Armbian that I have been using to play around with. I have been able to SSH into it from my iPad when on the move, run a nummber of my own apps, and even run a copy of OctoPrint for a while.

However, right now it has actually been dropped from the list of Armbian supported boards, so it will be interesting to see if it has a future at all.

Stability

The biggest problem I have with it that it randomly stalls–at first I thought it was the paltry 512KB of RAM, but even after setting up a swapfile I had a couple of strange hangups, so I mostly put it down to either overheating or just plain bad software.

The second is that it sometimes refuses to connect to Wi-Fi without any apparent reason even when sitting next to an access point.

I partially blame that on its use of NetworkManager (which can be annoying in and of itself), but even when it has good Wi-Fi connectivity it will randomly time out when installing packages.

So I rate it as somewhat unreliable, and with it being pretty much unsupported I cannot quite bring myself to use it for anything more than testing, or having an tiny Linux machine with me when traveling with .

Next Steps

One thing I will try relatively soon (provided I can be sure it stays up at least 24 hours in a row unattended) is running Klipper on it, since most of the critical parts are distribution agnostic and it does not really need to be upgraded frequently–time will tell if it will be reliable enough.

Hopefully the supply chain shortages will be behind us soon, but I still wish there was a small 1-2GB RAM board with an EMMC in a “Zero” footprint, and I suspect the Pi Foundation won’t be making one anytime soon…

So if you know of anything like that, drop me a line (or better still, lobby the manufacturer to see if they can send out review samples).

Update: a kind reader (thanks, Stanislav!) reminded me that the Radxa Zero exists and seems to be available in non-zero (hah!) amounts with both RAM and EMMC storage to spare. Pricing is… a tad high (€90-120 for 4GB RAM), even for the times we live in, but I will likely be ordering at least one once I figure out the right SKU and a reseller that doesn’t have insane shipping rates.

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