Old 11-27-2020, 07:55 PM   #3041
Tone Deft
Human being with feelings
 
Join Date: Aug 2020
Location: San Francisco
Posts: 298
Default

Quote:
Originally Posted by karbomusic View Post
that tuner solves pretty much every problem tuners have that usually annoy people
disagreed. I'm open for sharing but not openly. I'm free labor and can do stuff to create a margin.

those clip-on tuners are the shit, and now everyone has one when you can't find yours. or on the phone or inside the DAW. that stomp box is going on my Amazon wish list.
Tone Deft is offline   Reply With Quote
Old 11-27-2020, 08:54 PM   #3042
karbomusic
Human being with feelings
 
karbomusic's Avatar
 
Join Date: May 2009
Posts: 29,260
Default

Quote:
Originally Posted by Tone Deft View Post
disagreed. I'm open for sharing but not openly. I'm free labor and can do stuff to create a margin.

those clip-on tuners are the shit, and now everyone has one when you can't find yours. or on the phone or inside the DAW. that stomp box is going on my Amazon wish list.
OK.
__________________
Music is what feelings sound like.
karbomusic is offline   Reply With Quote
Old 11-27-2020, 09:00 PM   #3043
karbomusic
Human being with feelings
 
karbomusic's Avatar
 
Join Date: May 2009
Posts: 29,260
Default

Quote:
Originally Posted by clepsydrae View Post
I asked them three years ago if they were ever going to make a clip-on that tuned via conduction or microphone...
A clip on version of that tuner would be amazing.
__________________
Music is what feelings sound like.
karbomusic is offline   Reply With Quote
Old 11-27-2020, 09:57 PM   #3044
Tone Deft
Human being with feelings
 
Join Date: Aug 2020
Location: San Francisco
Posts: 298
Default

a guitar tuner for the blind using the technique I mentioned:
https://trybotics.com/project/Guitar...-Arduino-70465

a guitar tuner built into a string winder:
https://create.arduino.cc/projecthub...r-tuner-2093fe

proof of concept is done. these just need a fabricators, there's a market. port this code over to your own tiny uC platform of choice and go from there.

the science is well known and done many ways. why re-invent that part of it? so much more still to be done. not my idea though.
Tone Deft is offline   Reply With Quote
Old 10-23-2021, 01:46 PM   #3045
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Whoa we're coming up on a year without a post here... not on my watch!

Anyhow: I have several Raspberry Pi and Pi Zeros around running security cameras... one of them goes on the fritz now and then, usually associated with windy storms outside.

My theory is that for whatever reason (power supply?) it is flipping out due to voltage brownouts or spikes.

Assuming that's correct, I'm wondering about simple things I could do to prevent this. My uneducated question: can I just slap a capacitor to ground between the power supply and the Pi to smooth out the supply voltage/current? Maybe also a 5.1V zener to ground?

I'm obviously working with insufficient circuit theory here, but my understanding is that the cap could act as a voltage/current reservoir in case of voltage drop and the zener would prevent voltage surges? At the cost of a small warm-up time when it's first plugged in?

Am I off in the weeds?
clepsydrae is offline   Reply With Quote
Old 10-23-2021, 01:50 PM   #3046
karbomusic
Human being with feelings
 
karbomusic's Avatar
 
Join Date: May 2009
Posts: 29,260
Default

That will smooth it out a bit if it doesn't go low longer than it takes for the cap to discharge. If fairly transient which this sounds like, it might do the trick. Think of a power led on something you unplug that takes a bit for the led to slowly fade, I'm sure you know that's that same cap draining but mentioning for all. The value in MF of the cap determines how long that is but the caveat is it will delay initial powerup by the same amount while the cap charges up (IIRC that is, could be wrong).

And make sure the cap voltage is roughly double the voltage you are using, should be easy with 3.3 and 5 Volt units like this. 16V would be fine, larger than that is fine too as we only care about it not being spec'd with too low of a voltage (so the cap doesn't explode).
__________________
Music is what feelings sound like.

Last edited by karbomusic; 10-23-2021 at 01:57 PM.
karbomusic is offline   Reply With Quote
Old 10-23-2021, 05:15 PM   #3047
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Thanks!

Polarized or not? (This is something I can never get a handle on...)

Thoughts on the zener? And do I need to worry about over-rating the cap voltage rating if the zener is in place?

Here's the schematic I'm talking about.

In terms of cap size... I'm wondering if I'm thinking this through properly: say I want about 0.5 seconds of resilience, i.e. it can sustain a power loss of that long.

If the Pi draws a max of 5 or 6 watts while churning the CPU (so says the internet), that's about 1.2A. If I treat that as representative of the "effective resistance" of the load of the Pi, then I get ~4.2 Ohms. I do this so I can size the capacitor. Using the calculator here, if I do "from voltage" 5, "to voltage" 0.1, "supply voltage" 0, empty capacitance field, resistance 4.2, and time 0.5, and hit calculate, it gives me about 30.5 mF for the capacitor.

Checking on mouser, that's a $5 cap that is about 1.5" in diameter, 1.2" tall... that's a bit bigger than I expected, but I suppose not crazy given what I'd be demanding of it?

Any thoughts on this rigmarole? Thanks!
clepsydrae is offline   Reply With Quote
Old 10-23-2021, 06:43 PM   #3048
karbomusic
Human being with feelings
 
karbomusic's Avatar
 
Join Date: May 2009
Posts: 29,260
Default

Try polarized electrolytic starting at 100 Uf up to 1000 Uf'ish - higher numbers are slower to charge/discharge. Just throw it across the +/- on the power rail and match the polarity. I wonder if it gets too slow (bigger value) if it will mess with the boot process of the microcontroller. So keep that in mind. Pretty sure the value you need isn't large enough for that to matter, depends on how long and how far the voltage drops.

Edit: Some of this is already in the PSU or should be or good ones do, so that might be a clue. All that cap is is a poor man's marginally functional voltage regulator. I'm also thinking the Pi and/or Arduinos have this built in already.
__________________
Music is what feelings sound like.

Last edited by karbomusic; 10-23-2021 at 06:59 PM.
karbomusic is offline   Reply With Quote
Old 10-23-2021, 07:05 PM   #3049
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Quote:
Originally Posted by karbomusic View Post
I wonder if it gets too slow (bigger value) if it will mess with the boot process of the microcontroller.
Yeah I was worried about that, but I guess I'll find out.

Quote:
Edit: Some of this is already in the PSU or should be [...] I'm also thinking the Pi and/or Arduinos have this built in already.
Yeah I would hope there was something... but i was kinda out of things to try. I suppose I should probably start by swapping power supplies from one Pi to another to see if it moves the problem. But I thought it might also be line interference on the circuit that the problem Pi is on. Was just hoping to add some extra protection.

Thanks!
clepsydrae is offline   Reply With Quote
Old 10-23-2021, 07:24 PM   #3050
karbomusic
Human being with feelings
 
karbomusic's Avatar
 
Join Date: May 2009
Posts: 29,260
Default

Quote:
Originally Posted by clepsydrae View Post
Checking on mouser, that's a $5 cap that is about 1.5" in diameter, 1.2" tall... that's a bit bigger than I expected, but I suppose not crazy given what I'd be demanding of it?
That seems a little big but I really don't know. I'm more used to 10-15mm wide but I'm usually under an amp when I used them for this. I don't know about the zener unless it is polarity protection or something but that seems odd for a zener.

I have a Pi3 that due to how long the power cable is, and the power supply that it is coming from, the voltage is just lowered enough to cause the Pi to occasionally freak out. So maybe sanity check the incoming power after the adapter and/or before. Might be helpful to know what the baseline is.
__________________
Music is what feelings sound like.

Last edited by karbomusic; 10-24-2021 at 08:47 AM.
karbomusic is offline   Reply With Quote
Old 10-23-2021, 07:27 PM   #3051
karbomusic
Human being with feelings
 
karbomusic's Avatar
 
Join Date: May 2009
Posts: 29,260
Default

Quote:
Originally Posted by clepsydrae View Post
But I thought it might also be line interference on the circuit that the problem Pi is on. Was just hoping to add some extra protection.
It's certainly worth a try, there are plenty of power adapters that just barely do their jobs. Some aren't even regulated, they just over-voltage them so that the intended load brings them down to the advertised nominal voltage.

Either can be noisy if they don't do any filtering - like what we are discussing, these are just RC filters AFAIK, if a DC voltage bounces around, that's some type of waveform and we want to filter that out. You could search around for some basic power supply filtering, plenty of info that would likely bring you right up to speed. A better PSU might do it automatically, just depends on what the actual problem is. Drop outs, ripple/noise etc.
__________________
Music is what feelings sound like.

Last edited by karbomusic; 10-23-2021 at 07:34 PM.
karbomusic is offline   Reply With Quote
Old 10-25-2021, 11:05 AM   #3052
cyrano
Human being with feelings
 
cyrano's Avatar
 
Join Date: Jun 2011
Location: Belgium
Posts: 5,246
Default

I've used a somewhat deluxe version on occasion for wildlife cameras. Buy a couple 2.7V supercaps. Put them in series to attain 5.4V. Put a diode in front and detect the power drop before the diode. Find/write/steal a script that shuts the Pi Down gracefully when there's no more power coming in. A few Farads should provide ample time to do so.

Why?

The biggest problem with the Pi is SD cards going corrupt. If you've got one that has repeatedly gone bezerk, the chance the SD card is corrupt becomes high.

Test: feed it another, known good SD card and see if that helps.
__________________
In a time of deceit telling the truth is a revolutionary act.
George Orwell
cyrano is offline   Reply With Quote
Old 10-25-2021, 11:56 AM   #3053
C-H
Human being with feelings
 
Join Date: Apr 2015
Location: Tucson, AZ
Posts: 373
Default

Quote:
Originally Posted by clepsydrae View Post
Whoa we're coming up on a year without a post here... not on my watch!

Anyhow: I have several Raspberry Pi and Pi Zeros around running security cameras... one of them goes on the fritz now and then, usually associated with windy storms outside.

My theory is that for whatever reason (power supply?) it is flipping out due to voltage brownouts or spikes.

Assuming that's correct, I'm wondering about simple things I could do to prevent this. My uneducated question: can I just slap a capacitor to ground between the power supply and the Pi to smooth out the supply voltage/current? Maybe also a 5.1V zener to ground?

I'm obviously working with insufficient circuit theory here, but my understanding is that the cap could act as a voltage/current reservoir in case of voltage drop and the zener would prevent voltage surges? At the cost of a small warm-up time when it's first plugged in?

Am I off in the weeds?
Not completely.
Use a Super-Cap instead of a capacitor. It will hold a much bigger charge. It's like the middle ground between a battery and capacitor.
Zener diodes are kind of crappy regulators but will work OK for a known and constant load. Doesn't the Pi have on-board regulation already?
__________________
Stash : M-Audio Oxygen 49 KeyMap
Stash : M-Audio Oxygen 49 v2 KeyMap
C-H is offline   Reply With Quote
Old 10-25-2021, 12:45 PM   #3054
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Quote:
Originally Posted by cyrano View Post
The biggest problem with the Pi is SD cards going corrupt. If you've got one that has repeatedly gone bezerk, the chance the SD card is corrupt becomes high.
Yeah I've seen that first-hand... weird issues being fixed by a new SD card. I kinda thought this might not be SD related, just because when examining the system logs it really seems to just lock up entirely, i.e. nothing in the logs about strange file errors, etc... rather it just stops cold... maybe seems more like a hardware thing? Since it correlates with bad weather outside?

Quote:
Originally Posted by C-H View Post
Doesn't the Pi have on-board regulation already?
Yeah I assume... I'm kinda reaching in the dark here trying to fix it.

Thanks for the supercap tips!
clepsydrae is offline   Reply With Quote
Old 10-25-2021, 12:50 PM   #3055
karbomusic
Human being with feelings
 
karbomusic's Avatar
 
Join Date: May 2009
Posts: 29,260
Default

Quote:
Originally Posted by clepsydrae View Post
Thanks for the supercap tips!
Good call, I didn't even know those existed!
__________________
Music is what feelings sound like.
karbomusic is offline   Reply With Quote
Old 11-13-2021, 04:36 PM   #3056
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Mmmkay...

Switched the power supply with a different one: same result.

Reformatted/fresh-installed the OS (with upgrade from Pi OS 8 to 10) on a different SD card: same result.

I built the circuit described earlier.

..where the zeners are these, and there are two of these supercaps in series.

First I tested the unmodified power supply: 5.5V unloaded, got to voltage after 1-2 seconds.

Then I wired in the caps/zener and plugged in the power supply (with no attached load) and plugged it in. The voltage rose to about 2.5V only, and the capacitors got very hot. I waited maybe 20 or 30 seconds and the voltage never got above ~2.5V. I unplugged it out of fear for the caps...

Then I made sure the caps were discharged and plugged it back in. This time it only got to like 1.5V and leveled off.

Any ideas about what I'm doing wrong? Do I just need to wait longer? If so, that's maybe not going to work because I don't want the Pi to be seeing such a low voltage for so long... I was hoping for more like 0-3 seconds warm up time...

Thanks!
clepsydrae is offline   Reply With Quote
Old 11-16-2021, 11:05 AM   #3057
cyrano
Human being with feelings
 
cyrano's Avatar
 
Join Date: Jun 2011
Location: Belgium
Posts: 5,246
Default

Sounds like one or both of the supercaps are defective.

But why?

EDIT. Of course, silly me. You need balancing.

https://www.mouser.com/pdfDocs/ALD_N...capacitors.pdf

"Any capacitor put in series will increase the voltage rating of the capacitor. Keep in mind that supercapacitors are different from normal capacitors because of their very low ESR (Equivalent Series Resistance). The ESR could create problems if the current is being sourced fast enough to heat the capacitors (if the ESR rating varies by say 50% then the highest ESR capacitor will source most of the heat, in this case you will need to balance the capacitors."

Sounds simpler to buy a 5.5V one and avoid the problem completely.
__________________
In a time of deceit telling the truth is a revolutionary act.
George Orwell
cyrano is offline   Reply With Quote
Old 11-16-2021, 11:43 AM   #3058
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Aha! Thanks. Glad there's an explanation!

New caps ordered... let's see how it goes.
clepsydrae is offline   Reply With Quote
Old 11-18-2021, 03:26 AM   #3059
Tubeguy
Human being with feelings
 
Join Date: Sep 2016
Posts: 657
Default

When I'm burned out recording music, I usually build something. Amp, preamp, pedal etc. That gets me back to music as I love the inspiration I get from my builds to put some new ideas in to my music. Inspiration is something I never get from any plugin so for me building my own stuff is very rewarding.
__________________
My BandCamp
Tubeguy is offline   Reply With Quote
Old 11-18-2021, 11:48 AM   #3060
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Quote:
Originally Posted by Tubeguy View Post
building my own stuff is very rewarding.
Yeah there's definitely something about DIY'ing a piece of gear yourself, even if the cost/time/value accounting doesn't make any sense. :-)
clepsydrae is offline   Reply With Quote
Old 11-18-2021, 12:44 PM   #3061
karbomusic
Human being with feelings
 
karbomusic's Avatar
 
Join Date: May 2009
Posts: 29,260
Default

Quote:
Originally Posted by clepsydrae View Post
Yeah there's definitely something about DIY'ing a piece of gear yourself, even if the cost/time/value accounting doesn't make any sense. :-)
Absolutely!!!

And btw, which script/app are you using on your zero for the camera? I probably don't need it but I have a zero for some C programming stuff (unrelated) and figured I'd ask in case I decide to play with the zero camera wise.

I'm probably going to move all my MotionEyeOS installs from my Pi3's to Pi4 but who knows, hence the ask. I really like MotionEye but it's performance on Pi3 is marginal.
__________________
Music is what feelings sound like.
karbomusic is offline   Reply With Quote
Old 11-18-2021, 12:59 PM   #3062
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

I had really particular needs with my setup, so I did it all custom (in python). I'd be happy to send you the script if you want... it's pretty capable i guess... but it's maybe kind of annoying for someone besides me. :-)
clepsydrae is offline   Reply With Quote
Old 11-18-2021, 01:30 PM   #3063
karbomusic
Human being with feelings
 
karbomusic's Avatar
 
Join Date: May 2009
Posts: 29,260
Default

Quote:
Originally Posted by clepsydrae View Post
I had really particular needs with my setup, so I did it all custom (in python). I'd be happy to send you the script if you want... it's pretty capable i guess... but it's maybe kind of annoying for someone besides me. :-)
Yea if you don't mind. I get it so no worries about the annoying part - I'm in other peoples code all day every day.
__________________
Music is what feelings sound like.
karbomusic is offline   Reply With Quote
Old 11-24-2021, 12:55 PM   #3064
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Hmmm, so I got the new supercaps and wired things up. What's happening now is that the diode is overheating. My knowledge of such devices is limited, but: since it's "non-linear" does that mean that since the power supply is slightly over the rated voltage of the zener, it basically opens up to short circuit and passes whatever current the power supply can deliver?

That schematic again.

The power supply outputs like 5.4V with no load, so I'm guessing that explains that? Maybe I can't use a 5.1V zener in this case? Maybe I need to find a zener (e.g. this 5.6V zener) that can handle that voltage? My first instinct was to put a resistor in series with the zener to limit current, like you do with an LED, but something tells me that would mess with the zener's regulation of the overall voltage?

I did attach the 1F supercap and the Pi boots up with it fine so that seems to be working.
clepsydrae is offline   Reply With Quote
Old 11-24-2021, 01:15 PM   #3065
STOP
Human being with feelings
 
STOP's Avatar
 
Join Date: Jul 2013
Location: Québec
Posts: 484
Default

Quote:
Originally Posted by clepsydrae View Post
The schematic doesn't show any zener serie resistor?



Calculator here http://www.calculatoredge.com/electronics/zener.htm

Last edited by STOP; 11-24-2021 at 01:21 PM.
STOP is offline   Reply With Quote
Old 11-24-2021, 01:19 PM   #3066
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Quote:
Originally Posted by STOP View Post
The schematic doesn't show any zener serie resistor?
Yeah that's how I wired it up. Is that the mistake? Need to have a resistor?

And it's probably a mistake to use a 5.1V zener with a 5.5V power supply to begin with? I think I foolishly assumed that the zener would pass enough (mild) current to magically drop the output voltage to 5.1V, but in retrospect that seems foolish/too-simple.
clepsydrae is offline   Reply With Quote
Old 11-24-2021, 01:54 PM   #3067
STOP
Human being with feelings
 
STOP's Avatar
 
Join Date: Jul 2013
Location: Québec
Posts: 484
Default

Quote:
Originally Posted by clepsydrae View Post
Yeah that's how I wired it up. Is that the mistake? Need to have a resistor?

And it's probably a mistake to use a 5.1V zener with a 5.5V power supply to begin with? I think I foolishly assumed that the zener would pass enough (mild) current to magically drop the output voltage to 5.1V, but in retrospect that seems foolish/too-simple.
I tried the calculator with 5.6V and it's too low. Minimum Input Voltage is too low!
STOP is offline   Reply With Quote
Old 11-26-2021, 01:39 AM   #3068
cyrano
Human being with feelings
 
cyrano's Avatar
 
Join Date: Jun 2011
Location: Belgium
Posts: 5,246
Default

Is the zener meant to protect the supercap?

If not, you really don't need one, I think. The RPi is capable of handling 5.4V and maybe you should measure the PSU under load?
__________________
In a time of deceit telling the truth is a revolutionary act.
George Orwell
cyrano is offline   Reply With Quote
Old 11-26-2021, 09:56 AM   #3069
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Quote:
Originally Posted by cyrano View Post
Is the zener meant to protect the supercap?

If not, you really don't need one, I think. The RPi is capable of handling 5.4V and maybe you should measure the PSU under load?
I'm not sure what's happening to the pi so the thought was that maybe there are voltage drops or voltage spikes causing issues. The super cap is supposed to help with the drops and the zener is supposed to suppress any temporary spikes... Is that reasonable?
clepsydrae is offline   Reply With Quote
Old 11-26-2021, 01:51 PM   #3070
jerome_oneil
Human being with feelings
 
jerome_oneil's Avatar
 
Join Date: Apr 2010
Location: Seattle
Posts: 5,635
Default

Quote:
Originally Posted by clepsydrae View Post
I'm not sure what's happening to the pi so the thought was that maybe there are voltage drops or voltage spikes causing issues. The super cap is supposed to help with the drops and the zener is supposed to suppress any temporary spikes... Is that reasonable?
My experience with Pis is that their power management is awful. I had dozens deployed in the field tied into a pretty expensive commercial power supply (this is a railroad application), and they still fried themselves on a regular basis. I have another sitting on my shelf serving music and it also craps the bed on occasion.

I love Pis, but my opinion after that experience is Pis are hobby grade boards, so you get hobby grade quality.
jerome_oneil is offline   Reply With Quote
Old 11-26-2021, 04:17 PM   #3071
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Yeah I've gotten a similar impression. On the other hand, i have three other pis running 24/7 (in the same house, though on different circuits) and i don't think any of them have frozen in like 5+ years of operation... As Cyrano said i have had issues with sd cards causing all kinds of weird symptoms, but besides that things have been smooth. It's just this one that gives me trouble and it seems to either be bad hardware or bad power so I'm trying to rule out the power possibility with this cap/diode setup... As with most things electrical i know enough to have the kooky idea but not quite enough to totally follow through.:-)
clepsydrae is offline   Reply With Quote
Old 11-26-2021, 04:30 PM   #3072
Philbo King
Human being with feelings
 
Philbo King's Avatar
 
Join Date: May 2017
Posts: 3,201
Default

Quote:
Originally Posted by clepsydrae View Post
I'm not sure what's happening to the pi so the thought was that maybe there are voltage drops or voltage spikes causing issues. The super cap is supposed to help with the drops and the zener is supposed to suppress any temporary spikes... Is that reasonable?
A zener is ok for very low power. You'd probably be better off with a 3 terminal linear regulator IC using a decent heat sink for anything more than milliwatts.
__________________
Tangent Studio - Philbo King
www.soundclick.com/philboking - Audio streams
Philbo King is offline   Reply With Quote
Old 11-26-2021, 05:01 PM   #3073
jerome_oneil
Human being with feelings
 
jerome_oneil's Avatar
 
Join Date: Apr 2010
Location: Seattle
Posts: 5,635
Default

Quote:
Originally Posted by clepsydrae View Post
Yeah I've gotten a similar impression. On the other hand, i have three other pis running 24/7 (in the same house, though on different circuits) and i don't think any of them have frozen in like 5+ years of operation... As Cyrano said i have had issues with sd cards causing all kinds of weird symptoms, but besides that things have been smooth. It's just this one that gives me trouble and it seems to either be bad hardware or bad power so I'm trying to rule out the power possibility with this cap/diode setup... As with most things electrical i know enough to have the kooky idea but not quite enough to totally follow through.:-)
Yeah. SD cards are all over the map. There is no real standard for them. Sometimes the cheap ones just work and sometimes the 'industrial' ones are crap.
jerome_oneil is offline   Reply With Quote
Old 11-26-2021, 06:10 PM   #3074
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Quote:
Originally Posted by Philbo King View Post
A zener is ok for very low power. You'd probably be better off with a 3 terminal linear regulator IC using a decent heat sink for anything more than milliwatts.
Yeah my thought was that since it was only for temporary spikes now and then (if they are even happening) it might qualify as 'very low power'. Though apparently I've misunderstood some fundamentals as evidenced by my use of a 5.1V zener on a 5.5V power supply. Guess I'll try the 5.6V zener and see how it goes.
clepsydrae is offline   Reply With Quote
Old 11-26-2021, 08:27 PM   #3075
karbomusic
Human being with feelings
 
karbomusic's Avatar
 
Join Date: May 2009
Posts: 29,260
Default

Quote:
Originally Posted by clepsydrae View Post
Yeah I've gotten a similar impression. On the other hand, i have three other pis running 24/7 (in the same house, though on different circuits) and i don't think any of them have frozen in like 5+ years of operation...
I have too many that have been up and running 24/7 too, without issue since 2016. Conversely, pretty much all the microcontrollers I work with are power sensitive... Arduinos, ESP8266, ESP32, Pi Zero, 3 and 4. But seem fine if the power is good and steady.

What OS are you running? Raspbian light? Full? Other?

I fought a lot of Pi power battles when I was installing all my Pi3 Cameras, almost any cable length more then a few feet dropped the voltage and it wouldn't boot (or freeze etc.). However, I was able to meter that voltage drop. It didn't show me 5+ volts like yours so I knew that was the problem.

Are there any scripts you can run that will just log some info about the power subsystem? [date][time][some-voltage-or-other-metric] - that might tell you more about the *actual issue.

The LM317 is a good idea, I love them, use them on multiple projects (very easy build). But it might be better to grab a little buck converter, power it with an old laptop power supply and dial it into a solid 5.1 volts or so - maybe that will provide more wiggle room. I definitely try a different PSU if you haven't.

*I really wish we knew more about the actual thing that is happening.
__________________
Music is what feelings sound like.
karbomusic is offline   Reply With Quote
Old 11-26-2021, 09:34 PM   #3076
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Quote:
Originally Posted by karbomusic View Post
What OS are you running? Raspbian light? Full? Other?
Yeah basic headless Raspbian. Upgraded to the latest to see if it would help anything; no luck.

Quote:
Are there any scripts you can run that will just log some info about the power subsystem? [date][time][some-voltage-or-other-metric] - that might tell you more about the *actual issue.
Nice thought... Apparently newer Pi's do have some voltage monitoring (apparently they can only detect over/under a threshold, to pop up a warning about undervolting) but my older Pi does not.

Quote:
I definitely try a different PSU if you haven't.
I did already swap the power supply from one of the stable Pi's, to no effect. I think the power supply is solid (it's the 2.5A PSU that Adafruit recommends and sells). My gut is currently that either there is some random hardware problem with the Pi or the house circuit it is plugged in to is having some kind of fluctuations for some reason, hence the cap/zener approach... I should probably just get another Pi Zero and swap it out to see if that solves everything. Probably the cheapest/easiest route... funny that it doesn't occur to me just because "replace the entire computer" is not usually the cheapest way to solve a problem, especially compared to a capacitor and a diode. :-)

Quote:
*I really wish we knew more about the actual thing that is happening.
Me too! :-)
clepsydrae is offline   Reply With Quote
Old 11-27-2021, 12:02 PM   #3077
ashcat_lt
Human being with feelings
 
Join Date: Dec 2012
Posts: 7,271
Default

Maybe this is the thread to post this?

I went down a rabbit hole yesterday. Been kind of thinking about lighting in my basement live room. Have for a while been looking at those LED strip lights, and would really like to have them be somehow responsive to sound, but of course the basic things with the microphone and a couple presets just isn't going to cut it.

Led me to a tangent of "Hey! If the LEDs are individually addressable, then could they be used as an actual video display?" Answer there is yes, but to do it well it takes some rather expensive specialty hardware, an arduino, and some kind of serious power management. But, then I could kind of use all kinds of audio visualization techniques using a big boy computer. Might even use Reaper for that. Wouldn't have to be like HD at all. Even just widely spaced pixels would be better than nothing. But honestly, I think that's way beyond what I'm trying to get into now.

Slightly less ambitious, though I think not too terrible far off but with less specialized hardware required, I came across people making spectrum analyzers out of these things. This turns out to be an arduino, a special little chip to do the analysis which you can get on a board ready to hook up for like $6. Maybe less power? But I guess that just depends on how many LEDs I'm ultimately trying to run.

What I actually want is something like multichannel flashies so that my guitar makes it some flash one color and my bassist makes others flash another color and the drums do something and... I don't have that many audio outputs from any of my computers... BUT I don't need the actual audio. I need something more like the envelope from that audio. And I could encode that by modulating the amplitude of a sine wave somewhere in the middle of one of the 7 bands that the spectrum analyzer offers, and...profit?

But this would be my first delve into these mini computer dudes AND the LED strips, and I'm not super sure where to start. I don't have a whole lot of budget to put into it, but from what I'm seeing, really the biggest expense would be the light strips themselves. Maybe the power, but I do have a number of desktop power supplies that I could press into service if necessary.

Am I just babbling? Anybody got any pointers or advice on where I might start on any of this? Where I might get the best prices for usable strip lights? Uhh...anything?
ashcat_lt is offline   Reply With Quote
Old 11-27-2021, 04:27 PM   #3078
karbomusic
Human being with feelings
 
karbomusic's Avatar
 
Join Date: May 2009
Posts: 29,260
Default

Quote:
Maybe less power? But I guess that just depends on how many LEDs I'm ultimately trying to run.
Typically, LED strips like this usually allow a separate power supply than the microcontroller if you are using enough to matter. I have a few RGB strips I use here and there around the house - and a 16x16 matrix I dork around with.

https://learn.adafruit.com/rgb-led-strips/usage

David Plumber just wrote a fairly extensive driver he calls NightDriver for use similar to what you are asking:

https://www.youtube.com/watch?v=UZxY_BLSsGg

Also CNLohr does some pretty crazy stuff, he's got a few videos on his take on a music driver LED driver called ColorChord:

https://www.youtube.com/watch?v=s8qWqYTpCN4

At the end of the day, give it the right power, code up whatever you want because there are already plenty of samples to go with the default LED type/drivers (of which I forget the name WS something).

A video cube...

https://learn.adafruit.com/diy-led-video-cube


----------

Edit: I just realized there is a breadboard setup of RGB LEDs in my lab that reacts to audio via microphone with some flame type flow effect. I'll check to see if I tore it apart already or not but I could probably get it back up and running in an hour or so. I need to finish it and implement it already anyway.
__________________
Music is what feelings sound like.

Last edited by karbomusic; 11-27-2021 at 05:39 PM.
karbomusic is offline   Reply With Quote
Old 12-06-2021, 05:47 PM   #3079
karbomusic
Human being with feelings
 
karbomusic's Avatar
 
Join Date: May 2009
Posts: 29,260
Default

Yo, aschat:

https://youtu.be/XbE0Uy4CstY?t=241
__________________
Music is what feelings sound like.
karbomusic is offline   Reply With Quote
Old 12-18-2021, 07:29 PM   #3080
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,409
Default

Update on the Pi power thing: amazingly, putting the 5.6V zener in there seems to have fixed it! It's tentative still, but it was crapping out every couple/few days before, and since the zener was installed it hasn't crapped out in a couple of weeks, and counting. The supercap is still there as well -- gives it like 5-10 seconds of grace time if the power is cut, and doesn't seem to prevent booting (though it obviously takes a few seconds longer to power up.)

They do have protection diodes on the Pi's, but I wonder if this one took a nearby lightning strike or something and just got sensitized. At any rate, so far so good. Thanks for the help on it!
clepsydrae is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 02:46 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.