Old 10-18-2021, 12:39 PM   #1
Glennbo
Human being with feelings
 
Glennbo's Avatar
 
Join Date: Mar 2008
Location: Planet Earth
Posts: 6,922
Default Solar Pi

I decided to try powering my Pi and a small monitor using the DIY solar box I built a few months ago. Looks pretty promising.

Both the monitor and the Raspberry Pi 4 are only pulling 0.7 amps, and the battery is rated for 12 amp hours, which means it could run about 17 hours.

Now I need to figure out what midi and audio devices I could use with this.
__________________
Glennbo
Hear My Music - Click Me!!!
--

Last edited by Glennbo; 10-24-2021 at 07:19 AM.
Glennbo is offline   Reply With Quote
Old 10-18-2021, 02:01 PM   #2
audiojunkie
Human being with feelings
 
audiojunkie's Avatar
 
Join Date: Nov 2011
Posts: 321
Default

Very, very cool! Your very own off grid rig! Look into some of the midi keyboards and audio interfaces that are compatible with iOS and run off of USB. Apple was VERY restrictive of how much current draw they allowed to come from a connected external device to one of their iPads. If the device works on an iPad without needing a powered hub, then you can be sure that it uses very little electricity. Also, iOS devices have to be class compliant, so they should work with Linux. :-)

One device that I personally have that would likely work is the Keith McMillen Instruments K-Board Smart Sensor USB MIDI Keyboard Controller. It's light and built like a tank. It works fine on my iphone and ipad and Linux. Personally, I hate the "feel" of the keybed (or lack thereof), but I'd be willing to bet that it would work with your setup. It used to be about $60, but it looks like COVID has forced the price to raise to about $96 US.

I would only recommend it if you can handle the play (feel) of the keyboard. It's handy because it's small, and it's well built, but it's definitely not my first choice. However, I know that there are many other iOS supported devices that probably have a better feel that would still use a miniscule amount of current. :-)

Best of Luck! Let us know how it goes! I'm definitely interested! :-)
audiojunkie is offline   Reply With Quote
Old 10-18-2021, 02:13 PM   #3
audiojunkie
Human being with feelings
 
audiojunkie's Avatar
 
Join Date: Nov 2011
Posts: 321
Default

I just happened to see this:

https://www.kvraudio.com/news/nektar...-control-53057


I haven't looked into it at all, but it looks promising.
audiojunkie is offline   Reply With Quote
Old 10-18-2021, 08:59 PM   #4
Glennbo
Human being with feelings
 
Glennbo's Avatar
 
Join Date: Mar 2008
Location: Planet Earth
Posts: 6,922
Default

Quote:
Originally Posted by audiojunkie View Post
Very, very cool! Your very own off grid rig! Look into some of the midi keyboards and audio interfaces that are compatible with iOS and run off of USB. Apple was VERY restrictive of how much current draw they allowed to come from a connected external device to one of their iPads. If the device works on an iPad without needing a powered hub, then you can be sure that it uses very little electricity. Also, iOS devices have to be class compliant, so they should work with Linux. :-)
Low current draw is the top thing I look for in things to power by my two solar charged battery systems.

Quote:
One device that I personally have that would likely work is the Keith McMillen Instruments K-Board Smart Sensor USB MIDI Keyboard Controller. It's light and built like a tank. It works fine on my iphone and ipad and Linux. Personally, I hate the "feel" of the keybed (or lack thereof), but I'd be willing to bet that it would work with your setup. It used to be about $60, but it looks like COVID has forced the price to raise to about $96 US.

I would only recommend it if you can handle the play (feel) of the keyboard. It's handy because it's small, and it's well built, but it's definitely not my first choice. However, I know that there are many other iOS supported devices that probably have a better feel that would still use a miniscule amount of current. :-)

Best of Luck! Let us know how it goes! I'm definitely interested! :-)
Tanks! I ran what I had in the pic all day, and before the sun went down I parked a solar panel in the front yard, which charged back all the juice in my DIY solar battery box. Then I ran it all night on the patio just to push it some. Could easily run for a couple days before needing another charge from the sun.

Quote:
Originally Posted by audiojunkie View Post
I just happened to see this:

https://www.kvraudio.com/news/nektar...-control-53057


I haven't looked into it at all, but it looks promising.
I've looked at the 88 key version of that very same keyboard, and would have one by now except the "Midiman" (pre M-Audio name) Keystation 61 that I bought around the year 2000 still works, and I hate retiring gear that still works. The little one on the patio for jamming might be cool though.
__________________
Glennbo
Hear My Music - Click Me!!!
--
Glennbo is offline   Reply With Quote
Old 10-23-2021, 11:50 AM   #5
Glennbo
Human being with feelings
 
Glennbo's Avatar
 
Join Date: Mar 2008
Location: Planet Earth
Posts: 6,922
Default

I decided to setup the Raspberry Pi with some midi gear outside and record a jam powered by the Sun. I recorded eight tracks using SMDrums samples played with the Akai MPD26, plus a sampled grand piano, upright bass, Hammond organ, and a few synths including Helm, Dexed, and Surge played on the Novation midi keyboard.

From left to right top row,

Two 100 watt solar panels, Beaudens 166Wh Solar Generator, my 153Wh DIY Solar Generator, Leadstar 12 volt 1080p monitor, Raspberry Pi, JBL speaker, Behringer UCA202 audio interface, Novation 2 octave keyboard, Akai, MPD26 midi pad controller, Logitech wireless keyboard.



The Beaudens Solar Generator is providing the 110 volt AC power for the one wall wart being used. The old Novation keyboard was made before USB. My DIY Solar Generator is powering the Raspberry Pi, the Leadstar monitor, and the JBL speaker. The Pi is powering the Behringer UCA202 and Akai MPD26. Everything is getting its juice from the two 100 watt solar panels behind the table.
__________________
Glennbo
Hear My Music - Click Me!!!
--

Last edited by Glennbo; 10-27-2021 at 06:21 PM.
Glennbo is offline   Reply With Quote
Old 10-23-2021, 05:24 PM   #6
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,030
Default

Awesome!

So the keyboard is the only thing running on 120VAC? Does it run at some weird voltage? Did you think about providing it DC directly with a converter?

What kind of practical limits are there for power via the Pi over USB? Seems nice to just plug stuff in via USB and not have to worry beyond that.

You have some kind of step-down to 5V for the power supply to the Pi?
clepsydrae is offline   Reply With Quote
Old 10-23-2021, 07:11 PM   #7
Glennbo
Human being with feelings
 
Glennbo's Avatar
 
Join Date: Mar 2008
Location: Planet Earth
Posts: 6,922
Default

Quote:
Originally Posted by clepsydrae View Post
Awesome!

So the keyboard is the only thing running on 120VAC?
Yeah, I just didn't have anything to step down from 12 volts to the 9 volts that ancient Novation midi keyboard needs.

Quote:
Does it run at some weird voltage? Did you think about providing it DC directly with a converter?
I could get a step down transformer, but instead plan to get a newer USB powered midi controller with some pads so no 110 volt AC is needed, with fewer cables and a smaller footprint like the M-Audio Oxygen Pro 32 mini.

https://www.sweetwater.com/store/det...ard-controller

Quote:
What kind of practical limits are there for power via the Pi over USB? Seems nice to just plug stuff in via USB and not have to worry beyond that.
It was powering both the Akai pad controller and the Behringer audio interface with no problems. I would bet it could power a third or even a fourth device, provided it has a good power suppy coming into it.

Quote:
You have some kind of step-down to 5V for the power supply to the Pi?
I built my homebrew solar generator battery box with three standard cigarette lighter sockets, but I put double USB 3.0 quickcharge adapters into the two outer sockets, so I have four USBs and one full sized lighter plug. This is my homebrew solar generator. It consists of only three parts. A 12Ah LiFePo4 battery, a solar controller, and triple lighter sockets.

__________________
Glennbo
Hear My Music - Click Me!!!
--
Glennbo is offline   Reply With Quote
Old 10-23-2021, 07:16 PM   #8
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,030
Default

Right on. Do you run one panel to each battery?
clepsydrae is offline   Reply With Quote
Old 10-23-2021, 08:08 PM   #9
Glennbo
Human being with feelings
 
Glennbo's Avatar
 
Join Date: Mar 2008
Location: Planet Earth
Posts: 6,922
Default

Quote:
Originally Posted by clepsydrae View Post
Right on. Do you run one panel to each battery?
Yes. And each panel has 30+ feet of cable so the panels can be sitting out in the yard getting sun, while using the power from them in the house.

The store bought Beaudens 166Wh solar generator has a built-in 150 watt max 110VAC outlet. My DIY box has no AC inverter because ultimately I want to run everything on DC.

Once I get a newer USB powered midi keyboard controller with a few pads, I can skip using the solar generator with the AC outlet, and power everything I need off my DIY solar box.
__________________
Glennbo
Hear My Music - Click Me!!!
--
Glennbo is offline   Reply With Quote
Old 10-23-2021, 08:56 PM   #10
clepsydrae
Human being with feelings
 
clepsydrae's Avatar
 
Join Date: Nov 2011
Posts: 3,030
Default

I really like the idea of this as a platform for remote/wilderness tracking... battery, 4-XLR interface, 12V screen, keyboard & mouse... few mics and stands... cables... could fit it all in a single backpack except for the panel, which, I guess they have the roll-up panels nowadays?
clepsydrae is offline   Reply With Quote
Old 10-24-2021, 07:06 AM   #11
Glennbo
Human being with feelings
 
Glennbo's Avatar
 
Join Date: Mar 2008
Location: Planet Earth
Posts: 6,922
Default

Quote:
Originally Posted by clepsydrae View Post
I really like the idea of this as a platform for remote/wilderness tracking... battery, 4-XLR interface, 12V screen, keyboard & mouse... few mics and stands... cables... could fit it all in a single backpack except for the panel, which, I guess they have the roll-up panels nowadays?
They've got folding solar panels like this one, that would fit into a backpack.

I got into solar power initially because of a power outage that was going into the night, which made me realize we were going to be in the dark. The power came back on shortly after, but the next day I bought the Beaudens 166Wh box and some USB powered light bulbs like these and last Winter when we had three days without power due to an ice storm, I had lights and an 18" USB powered ceiling fan to circulate heat from a gaslog fireplace. It kept our phones and tablets charged too.

Since building the second solar generator, I've done a couple of dry run tests, and I can power my cable modem and WiFi router with direct 12 volts DC from the Beaudens box and also power two USB lights for over 12 hours just on battery, which is plenty long enough for after the Sun goes down. That leaves the other box for more lights, fans if needed, and charging phones, Etc.
__________________
Glennbo
Hear My Music - Click Me!!!
--
Glennbo is offline   Reply With Quote
Old 10-24-2021, 02:16 PM   #12
Glennbo
Human being with feelings
 
Glennbo's Avatar
 
Join Date: Mar 2008
Location: Planet Earth
Posts: 6,922
Default

Quote:
Originally Posted by audiojunkie View Post
I just happened to see this:

https://www.kvraudio.com/news/nektar...-control-53057


I haven't looked into it at all, but it looks promising.
I couldn't wait (nobody has the new Nektar Mini) and bought an M-Audio Oxygen Pro Mini which is similar, but with 7 more keys, some sliders and few other things.

__________________
Glennbo
Hear My Music - Click Me!!!
--
Glennbo 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 08:38 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.