Any Suitable alternative to the Raspberry Pi?



  • I have just had a second Rpi-3b+ Die while attached to a Duet-3 board.

    I only use the 3b+ over the 4 because the lower power consumption allows me to power the pi from the Duet-3, I don't attach anything else to the pi's either so I don't think it is a ground loop.

    I put the first mortality down to the possibility that because I bought the Rpi from Aliexpress that it could be some cheapo.

    The first Rpi board exhibited issues with the home all command failing with the printer halting as soon as the x stop was hit and then the printer froze becoming unresponsive. A reboot seemed to cure it, I was also chasing random terrible print quality that I put down to the filament.

    Then the printer would home fine but as soon as the print file started to lay down the prime line it would freeze again. And this time a reboot didn't cure it, and this time the z axis display was showing a infinite negative number

    So I started the diagnostic process.

    Changed the file I was printing incase it was somehow corrupt. No change.

    Changed the slicer. No change.

    Tried a new SD card still no change.

    I keep a pre-built SD card for standalone mode.

    Ran the Duet-3 in standalone mode and this printed different files 5 times in a row without issue. (and print quality went up by a huge amount)

    So we found the issue..

    I took the Rpi out and put in a spare I had bought locally that one is still running.

    The Rpi still boots on the bench with a screen and keyboard/mouse but as soon as you connect it to a Duet-3 it freezes.

    Today another UK purchased Rpi in another Duet-3 equipped printer started playing up with the very same symptoms as the first one... Tested the board in standalone and this cured the problem. So again I put a spare Rpi in.

    So back to the original question is there any viable alternative to the Raspberry Pi as a SBC with the Duet 3? (other than just running in standalone mode)



  • @CaLviNx Sounds similar to what was happening to me. Get the the 3.2beta2. https://github.com/Duet3D/RepRapFirmware/releases/tag/3.2beta2

    You'll need to change to the unstable release to do it via the SBC.
    https://duet3d.dozuki.com/Wiki/Getting_Started_With_Duet_3#Section_Software_Installation



  • @Stephen6309 said in Any Suitable alternative to the Raspberry Pi?:

    @CaLviNx Sounds similar to what was happening to me. Get the the 3.2beta2. https://github.com/Duet3D/RepRapFirmware/releases/tag/3.2beta2

    You'll need to change to the unstable release to do it via the SBC.
    https://duet3d.dozuki.com/Wiki/Getting_Started_With_Duet_3#Section_Software_Installation

    I forgot to mention that I am already on beta 2 so that's not it.



  • Are you using 5V from the Duet to power the pi ?
    Could it be that you are drawing more power over the 5V bus than the Duet can provide ?
    Power supply issues are extremely common in pi's - partially because of poor quality wall warts but also because a very thin gauge wire is used in the standard supply cables and that can cause a surprising voltage drop.

    I haven't contemplated this to any degree so I might be totally off base here but I would run the pi off the 12 (or 24V) power with a voltage converter just before the pi.

    I have also run into a number of SD cards failing over time and now use only cards that are rated for severe duty. None of these have failed yet.

    As a side note, not a single pi that I have ever owned has died on me. It's always been the SD card or power supply.



  • @jens55

    I'm sorry but did you actually read my initial post?

    As from your reply It appears you didn't.

    I already said the following:

    <
    I only use the 3b+ over the 4 because the lower power consumption allows me to power the pi from the Duet-3
    <

    And anyone who has been on the forum for any length of time will know there was previously a discussion started by myself with regards SD cards, where the end result concluded in me purchasing a bulk quantity of Scandisk "industrial" cards which have proven to be reliable.

    I have Rpi's around the house running my security system and hvac systems and those are all running fine with no issue, its only since linking the Rpi to the Duet that things have gone pear shaped.



  • @CaLviNx Just a long shot as I run stand alone myself and know diddley squat about RPi's but is there a possibility that the problems might be due to not shutting the RPi down cleanly? If you already have measures in place to do this, then just ignore this post. But there have been a few discussions about simply "pulling the plug" on the RPi when shutting down the printer (which is what I thing the default behaviour is) and that not necessarily being good thing to do.



  • The last time my Duet3 board driven printer was up, the RPi4 (getting 5V from the Duet3 board) wouldn't boot up cleanly until the PSU was up and running a couple minutes (I use a completely overspecced MeanWell 450W 24V PSU) ... looks like I need to change the power path to the RPi4 sooner rather than later.

    Talking about alternatives, Jetson Nano and BananaPi should be drop-in replacements.



  • @CaLviNx said in Any Suitable alternative to the Raspberry Pi?:

    So back to the original question is there any viable alternative to the Raspberry Pi as a SBC with the Duet 3? (other than just running in standalone mode)

    I am using a lot of orangepi boards here and they are pretty quality boards ... I have much better experience with them than with rpi.. but

    • they have connector rotated by 180 degrees (not all of them)
    • they do not run raspbian but armbian or something else
    • they use different cpu and other parts are different so not all sw works 1/1

    I never tried them with duet, have not tried to setup duet sw on them etc etc... but I do use them for e.g. to run octoprint.. if the duet sw works on them it would be good replacement... I did not want to test yet as wanted the easy testing with what's supported out of the box



  • @deckingman said in Any Suitable alternative to the Raspberry Pi?:

    @CaLviNx Just a long shot as I run stand alone myself and know diddley squat about RPi's but is there a possibility that the problems might be due to not shutting the RPi down cleanly? If you already have measures in place to do this, then just ignore this post. But there have been a few discussions about simply "pulling the plug" on the RPi when shutting down the printer (which is what I thing the default behavior is) and that not necessarily being good thing to do.

    You might be on to something there, I currently just flick the power switch to off.

    I have just purchased a number of power modules with latching relays that I will see if I can wire them in such a way as to add the required functionality to allow me to power everything down in a more elegant manner.

    I am severely considering pulling all the Rpi's from the Duet-3's as I have noticed a huge improvement in start-up times of the D.W.C. in standalone mode, This alone seems a very good reason to spend the time running a few extra ethernet cables from the hub in my workshop to the printers.

    The SBC comes across as a very good idea in theory but in practice I dont "yet" a very good use case for it.


  • administrators

    @CaLviNx said in Any Suitable alternative to the Raspberry Pi?:

    I am severely considering pulling all the Rpi's from the Duet-3's as I have noticed a huge improvement in start-up times of the D.W.C. in standalone mode, This alone seems a very good reason to spend the time running a few extra ethernet cables from the hub in my workshop to the printers.

    In my experience, a Pi takes between 30 and 60 seconds to boot up. That's the cost of running a heavyweight operating system (Linux) and getting the facilities and flexibility that it provides. Whereas a Duet boots up in less than a second, unless there are delay commands in config.g.

    The value of the RPi will increase as more plugins become available that need the facilities provided by the Pi.



  • @CaLviNx powering off RPI (or any other SBC) can lead to SD card corruption but that's about as bad as it can get. There's no way to kill anything by turning the power off. Now I can't confirm the situation where you power it from the DUET3, will DUET3 when you yenk the power off maybe send some spike on the 5V rail for the SBC and kill it, or wil the 5V rail start to go slowly down and that affects rpi badly (dunno why it would but..) but just removing power from the RPI cannot kill it, it can only corrupt the SD card (but even that is very hard if you are running XFS or EXT4)



  • @CaLviNx said in Any Suitable alternative to the Raspberry Pi?:

    The SBC comes across as a very good idea in theory but in practice I dont "yet" a very good use case for it.

    My thoughts exactly. I still have an RPi bolted to the machine but it isn't wired up (and hasn't been for 15 months or so). I might change my mind if and when I see some benefit that will outweigh the extended start up time.



  • @dc42

    I honestly never considered it until I ran the board in standalone mode, it really opened my eyes.

    As for the use case of the SBC, The key words are "in the future" but currently the feature set in the here and now does not warrant putting up with such an extended boot time delay.



  • @CaLviNx said in Any Suitable alternative to the Raspberry Pi?:

    @jens55

    I'm sorry but did you actually read my initial post?

    As from your reply It appears you didn't.

    I already said the following:

    <
    I only use the 3b+ over the 4 because the lower power consumption allows me to power the pi from the Duet-3
    <

    And anyone who has been on the forum for any length of time will know there was previously a discussion started by myself with regards SD cards, where the end result concluded in me purchasing a bulk quantity of Scandisk "industrial" cards which have proven to be reliable.

    I have Rpi's around the house running my security system and hvac systems and those are all running fine with no issue, its only since linking the Rpi to the Duet that things have gone pear shaped.

    There is zero need to get your knickers in a knot! I simply threw out some information that you might or might not have considered.
    Yes, I did read your post (twice, possibly three times) and although you said that you were powering the pi from the duet, you failed to specify exactly how you did that - hence my suggesting that the 5V rail might not have sufficient power.
    While I have been on this forum for quite a while, I have better things to do then follow every post - I scan the new post subject lines and on occasion something catches my eye and I respond. I rarely research the past posts of an individual poster so the fact that you bought a raft of industrial cards is unknown unless you mention it. Further, unless you mention that you are actually USING those industrial cards, I can not assume that yu are not using a card that came out of a gumball machine!
    In summary, while I know that you are facing a frustrating issue (been there, done that, have the T shirt), I would suggest that you might think about not shooting the messenger.
    BTW, while not explicitly mentioned (my bad), pulling the plug instead of doing an orderly shutdown is the same as a power problem .... which you have admitted to.
    I stand by my post about your issue being power related and not related to the pi itself.



  • @jens55

    Respectfully and for your own sake I request you Step well back, because I will bite more than once if provoked..



  • There you go again .... <sigh>
    I am in no particular need for entertainment at this time so I will leave you and your pi issue to work it out yourself!
    Peace ! I'm outa here .... stepping well back while being reminded about the story of leading a horse to water .....



  • @jens55 said in Any Suitable alternative to the Raspberry Pi?:

    There you go again .... <sigh>
    I am in no particular need for entertainment at this time so I will leave you and your pi issue to work it out yourself!
    Peace ! I'm outa here .... stepping well back while being reminded about the story of leading a horse to water .....

    I'm a little confused, correct me if I'm wrong but why did you mention anything about providing an opinion on correcting what you perceive to be the reason for the issue I encountered?

    I don't actually remember writing anything about asking anyone for assistance with rectification of the issue I encountered, that being so you took it upon yourself to provide a solution when not requested to do so.

    The only thing I did ask for an opinion on, was if there was an alternative to the Rpi as a SBC for the Duet-3, I thought that was quite clear. Evidently not clear enough for you.



  • Ok, to directly address your question: No, to my humble knowledge, limited as it may be, all SBC's on the market today require a stable source of power which unfortunately seems to escape your grasp.

    Hopefully that answers your question in a clear and concise way.

    (remainder of post deleted it in the interests of civility)

    Edit: Congratulations on being the first person that I blocked from view.



  • @jens55 said in Any Suitable alternative to the Raspberry Pi?:

    Ok, to directly address your question: No, to my humble knowledge, limited as it may be, all SBC's on the market today require a stable source of power which unfortunately seems to escape your grasp.

    And again flogging a dead horse with regards answering an un-asked question, as the ACTUAL question was about ANY SUITABLE REPLACEMENT for the Rpi NOT how much power (or the stability thereof) the SBC's Require. And still that fact escapes YOUR GRASP

    Power Supply isn't (or shouldn't be) an issue which is why I never mentioned anything about power, I try to carry out my due diligence to the best of my abilities and decide what I am required to do to complete the required task successfully.

    I run the same core components in all my printers, it makes things simple in numerous ways, Although I am a Mechanical Engineer, H/V electrics has always been an interest and doing things the "right-way" always been a personal pride.

    So I only use the following core components

    Duet Boards
    Meanwell LRS-450-24 PSU’s.
    E3D 40Watt hot end Heaters
    Filafarm Silicone A/C Bed Heaters
    Croyden SSR's
    My Motors always come from Stepper-On-Line (been using them for years with good results)
    Decent Quality Silicone wire

    And more recently adding Raspberry Pi's to the mix

    From the above I recon i'm pulling around 50 to 60 watts from a PSU rated to supply 450 Watts.

    I only used The Rpi-3B+ becuase it is listed as requiring a PSU supply of around 2.5 amps,
    and listed as pulling 2.1 watts max with no peripherals attached (and I dont attach anything) so the power requirements are less than the Rpi-4

    Now if there is any issue with how Duet-3 supplies the SBC in the recommended way via onboard 5V rail and jumper settings to supply the SBC then that is a design fault, but I dont think that is the problem.

    I did make a discovery today that i dont know if it is relevant or not.

    I am building another Core-XY and its in the stage of laying out for component placement and wire routing, I pulled another new Duet 3 off the shelf to connect it to the Rpi and from having just pulled the dead one out of the other printer just a few days ago I noticed that the supplied ribbon cable on the newest board was shorter than the one I pulled the other day.

    So I went for a look at the rest of the printers with Duet-3’s now I don’t know if it makes any difference but both printers that the Rpi’s died in both have the longer ribbon cables and the others that have been running with no issues all have shorter ribbon cables. All the Ribbon cables were supplied to me with the Duet-3's

    The shorter cables are all about 50mm shorter

    @DC42 would there be any reason for this to be a factor?

    IMG_20201101_152324.jpg



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  • administrators

    @CaLviNx said in Any Suitable alternative to the Raspberry Pi?:

    So I went for a look at the rest of the printers with Duet-3’s now I don’t know if it makes any difference but both printers that the Rpi’s died in both have the longer ribbon cables and the others that have been running with no issues all have shorter ribbon cables. All the Ribbon cables were supplied to me with the Duet-3's
    The shorter cables are all about 50mm shorter
    @DC42 would there be any reason for this to be a factor?

    We were originally using off-the-shelf ribbon cables so we accepted the length that that came in. When they went out of production, we switched to custom made cables, so we have them made to the length that we consider optimum. I can't think why ribbon cable length would be a factor. It's possible that the shorter ones might support a slightly higher SPI frequency.

    How many Duet 3 boards do you have? Are they all the same board version?



  • @dc42 said in Any Suitable alternative to the Raspberry Pi?:

    @CaLviNx said in Any Suitable alternative to the Raspberry Pi?:

    So I went for a look at the rest of the printers with Duet-3’s now I don’t know if it makes any difference but both printers that the Rpi’s died in both have the longer ribbon cables and the others that have been running with no issues all have shorter ribbon cables. All the Ribbon cables were supplied to me with the Duet-3's
    The shorter cables are all about 50mm shorter
    @DC42 would there be any reason for this to be a factor?

    We were originally using off-the-shelf ribbon cables so we accepted the length that that came in. When they went out of production, we switched to custom made cables, so we have them made to the length that we consider optimum. I can't think why ribbon cable length would be a factor. It's possible that the shorter ones might support a slightly higher SPI frequency.

    How many Duet 3 boards do you have? Are they all the same board version?

    I have 6 Duet 3's , 1 is a 0.6 pre-production board and the other 5 are 1.0.1 revisions, it was 1.0.1 boards that had the Rpi's that died in them.

    I have shortened all (long) my ribbon cables of any unnecessary material.

    I just purchased a banana pi bpi-m3 as allegedly it has the same pin-out as the Rpi and again will allegedly run Raspbian OS out of the box, so we will see what it does when it arrives.


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