yesterday I had a really stupid problem in the rehearsal room: shortly before the rehearsal I tested my Zynthian at home: everything was running. But apparently I disconnected the power supply too early and I had to notice that the SD card was no longer readable at rehearsal room.
This problem is not good for live performances. Unfortunately there is also an unpredictable power failure live…
My first idea was to design something with some goldcaps myself, but no: there is already such a solution. Admittedly: not cheap, but ready for it and well thought out: https://juice4halt.com/products
I’m thinking about buying something like this and hope it still fits into the Zynthian v2 case.
Hey, I’m new to this world and I’ve been reading a lot these days. Somewhere I read you can have two sd cards, so you can have a backup sd card ready if it gets corrupted.
Hm, I thinks that this will not work. The problem is, that buffers are not written to the filesystem when powering down hard. So, if they are not written to one sd card they won’t be written to the other, too (IMHO).
Boot the in Read Only mode for gigs and read-write for making snapshots and remember to shutdown cleanly. Record to external USB. Possibly holding down one of the four switches on boot to select rw mode?
Hm, yes. Much work and the big question is: If this will work, will it be used for the Zynthian image or do I have to create my own Zynthian image for every new version… So I think I will go the hardware way.
Model Qty Price Amount
J4H-5V-USB 1 39.00 EUR 39.00 EUR
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Subtotal 39.00 EUR
Shipping 6.60 EUR
PayPal fee 2.28 EUR
VAT (19%) 9.10 EUR
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Total 56.97 EUR
The estimated delivery time is 1-3 weeks.
Hmmm… The problem will be to get it inside the case. Or I have to build a new case… so I can think about my next Zynthian integrated directly into a keyboard… perhaps the v3?
To avoid similar situations, now I always carry a cloned copy (or two) of sd cards. Regarding the power, I switch from micro usb to more reliable connector (and more reliable power supply that can give actual 3A when needed).
Also, my problem was having no good ground in some performance venues, so there was hum and noise in some places. So I thought of an idea to use ferrite rings - old school way in case we use power supply. Battery power is also a nice solution imho.
Strange they use 2.7V capacitors. One of those would avoid a 0.5V drop of a 2A load for approx. 22 seconds (if my O Level physics is remembered) so I would guess it can support about 10s outage before things go off. I will be looking at a Li-ion batter backup so as to have full UPS and portable power.
I use this board in other installations where I need an “UPS” for rPI. Never had a problem… it can talk with rPI on I2C, so it should be not so hard to integrate it (or something similar) in Zynthian system.
I’m planning on something similar to the Pi UPS @Axeman is using for the live rig I’m building. I like the Juice4Pi solution, but it’s expensive to get it in the US, and it does appear to be as easy to use with REBOOT scripts and other modifications required.
