Argon ONE Case for Raspberry Pi 4 Updated

The Argon ONE case is very pretty (but then it is not cheap so you’d expect that). It has variable control over the built-in fan and I had to ramp up the settings as the fan was initially off even though the case was very warm – now the whole thing runs cool.

It also has a multi-function power button which operates as follows:

If the power is currently OFF, a short press turns the power ON. Otherwise there are 3 press options: >=3 seconds for soft shutdown and power cut, >=5 seconds for forced shutdown, double–tap for reboot.

Installing software to control the fan:

curl | bash

The default software setting automatically assumes that after a power failure, you want the power to remain off. You can change that behaviour with a simple i2c command which is available on the RPi command line after installing the software.

Argon ONE RPi4 csae

Personally, after power loss, I want the RPi to resume to staying ON AS IT ALWAYS HAS done.

The LAST thing I want is a dead PI after power failure (which can still happen even if you have a UPS). If a mains power breaker goes and your UPS times out, using the wonderful power button on this case you have to BE THERE to get the Pi powered up again. Not clever – at least not at first sight.

Initially, with a slight hack, I easily bypassed the on-off switch without making any circuitry changes (just removing a little bit of the included PCB).

Argon ONE

After hacking – with a slight piece of PCB removed to access the original RPi USB C connector (and before anyone says “you shouldn’t have hacked it” – as it happens I ordered two cases – though the external packaging for the second unit looks nothing like the first – read on as you DON’T have to hack this case given the info below).

RPI4 with Argon ONE circuitry - hacked

Here’s the finished hack job minus connector cover – I plan to use an OLED status display…

Finished hacked RPi4 case

The top half of the case is aluminium and it has a solid feel to it. Note that the ability to boot the RPI4 from USB is covered elsewhere in the blog and is new (not so for the RPi3 which has had this feature for ages, albeit with the relatively useless USB2). I do like the label for port connections – nice. And here’s the short video…

And here’s the update – ARGON40 emailed me back after a couple of days and here is the content of their email:

Apologies for the late response. You can check out our i2C guide in the link below to see if you can do something with your Argon ONE Case:

We hope that this will be able to help you out.

So, setting MODE 2 allows the unit to turn ON automatically after loss of power. Erm, what?

As it happens, helpful blog subscribers sent me in the correct i2c command to fix the power off issue. Run this at the command-line and you have an auto-power-up Pi.

i2cset -y 1 0x01a 0xfe

Easy. While this case doesn’t solve the issue of where to store that massive SSD drive you just bought, it does everything else including a having quiet, cool, neat-looking housing for your Raspberry Pi4. Hopefully future revisions of the manual will make this all a lot clearer.

I hope to report on this over the summer as I’m expecting a replacement case for the one I hacked. I have to say, the company were very helpful when contacted. And for clarity – apart from the obvious hole in the side, my board is now un-hacked and working as expected – comments in here indicate that very early boards may not necessarily perform the same way.

Argon ONE case for RPi4

19 thoughts on “Argon ONE Case for Raspberry Pi 4 Updated

  1. Hi Peter
    I’m new to SBCs and raspberry pi, I got the same case for the raspberry pi 4 which also runs very warm, I just wanted to know what settings you changed, so that the case runs cool.

    1. In the booklet there’s a manual setting for the fan, I ramped it up until I could just hear the fan close up – seems cool now and it kept the setting. Next I need to ask the company how we’re supposed to use the power I2c settings in the update link above (i.e. if we do know how to use the i2c settings, how do we make sure they stay put after power cycling).

      I’ve left the question as an issue in their repository on Github.

      1. Peter,

        I tried the following:-
        i2cset -y 1 0x01a 0xfe

        It seems to be maintained across power cycling. I think it effectively bypasses all control of the power switch on the case.

        It can then be put back to its defaults using:-
        i2cset -y 1 0x01a 0xfd

        Hope that helps.

            1. Myles, You could test that the i2cset command is working as expected by using it to control the fan. For example:-
              i2cset -y 1 0x01a 0x64
              This should turn the fan on at 100%. It will reset when the service cuts in every 30 seconds to check the temperature.
              In my experience “i2cset -y 1 0x01a 0xfe” then shutting down with “halt” and removing power and then reapplying power will boot straight back up. Reverting to the default (0xfd) then requires use of the power switch on the back again.

              What I couldn’t find was a way of reading back the values of any of the data/registers using i2cget. Every attempt returned the value 0xc8. Maybe that is by design.

              Good Luck

              1. Hi SteveH – I concur and have updated the blog accordingly as well as using this info on my latest Raspberry Pi 4 and Argon case. After issuing that I2C command on the latest firmware (the CURL command in the manual), I now have a working auto-power-on Pi.

                1. Hi Peter Scargill,

                  What do you mean by: “latest Raspberry Pi 4 and Argon case”
                  Do you mean the fixed one that has no USB-C Power issue?

                  I have tried the lastest “firmware” script from the manual. But still after running: “i2cset -y 1 0x01a 0xfe”

                  When I power off the Pi, cut the Power, give it back. Still have to press the button.

                  Note: I have one of the first Pi4 (still with power issue) and one of the first Argon One

                  Thanks in advance.

                    1. UPDATE:
                      They responded in the Repo.
                      It seams that there are different Versions of the Argon One “Board” with different Firmwares on it.

                      If someone has the old one, it wont work with Code, because the MCU needs an Update.

                      They are thinking of a Jumper Method for that to keep “the old ones and new ones” Always On.

                      With that said it dose not realy depend on the Pi itself. More on the board of the Argon One.

  2. The micro HDMI ports are very poor, I have had mine replaced twice as moving the cable the picture is lost on the screen. I replaced the cooling pads today with some decent 1.5mm ones bought on eBay and it now stays under 40c most of the time with the fan coming on at 40c.

  3. I have had problems with the HDMI ports as well. I’ve been meaning to contact Argon40 about it. It’s a great case if I didn’t have this problem.

    1. Erm, there is of course a heatsink in there but there is also a fan. The fan control works but their settings are not that good, with a little tweaking the case runs cool with almost no fan sound unless your ear is pressed to the case.

      1. Agreed, I also have the case…. Was just point out to others that the case getting warm isn’t a problem – it is part of the design.
        Have Argon said anything about having a default on and use button for off mode? That would be useful for headless applications. For my use (RetroPie) it works ok as it is.

        1. No reply from Argon yet Tony – if and when they reply I’ll put it in here. Headless, yes and also in my case unattended. I had to completely bypass the switch.



  4. In response to LucaM – lets hope the company communicate w- we can get get in here and then everyone can have confidence they can fix the earliest cases. I’ve already fixed mine so now I have two (with a third to follow) all able to auto-power up without issue – I know that for sure, as always-on is very important to me.

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