Dreamcatcher Case for Travel


#1

Let’s start a new Topic on Dreamcatcher Cases

Syed has indicated he is working on some new ideas on containers to hold the Dreamcatcher Skylark system. Well, since I travel allot with Outernet in my “go bag”, I wanted a compact way to hold everything. The Simplest solution pictured below uses the old Alpha Lantern case

The only thing I haven’t done yet is gain access to the power off button. I can shutdown from PuTTY with SUDO POWEROFF - - or pull the power plug (which I don’t like doing).

I miss the internal LiPo battery the Lantern (CHIP/LNA/SDR/Patch) had which gave me portability. So I am powering my device with a 6,000 mAh Solar/external USB power device.

When I travel away from an ac outlet, I strap Solar package to the back of the Dreamcatcher case. When fully charged (trickle charge from ac keeps unit fully powered), I have several hours of portable usage. Ken


#2

very Nice :sunny:


#3

I tried something similar out yesterday, not enough power or sun for my 1a USB solar panels to keep a 6000mah pack charged all day AND run the Dreamcatcher, it did run for most of the day though.

FYI, I’m pretty sure that holding the power button is the same as pulling the plug since a short-press doesn’t go through the shutdown process like it did with the Armbian image.


#4

I’m not depending on the sun either. The power pack runs the Dreamcatcher fine, but time will tell if my USB charger will up with the Dreamcatcher’s draw on the LiPo to keep the power pack fully charged.

So far - - acidentally pulling the power cord off hasn’t had any adverse effect. Ken


#5

What I’m working on is a laser cut/folded metal enclosure. It won’t be weatherproof, but it will shield against the the EMI that comes off the board. We can’t reliably place the antenna directly above Dreamcatcher without some shielding. The goal is to put the antenna in the middle and have two solar panels on either side–the size of the Lantern will not increase.


#6

Short update on external power pack for Dreamcatcher

Unit ran for 2 days on stored power out of the 6,000 mAh battery power pack with it plugged in and charging, but then failed. The power pack’s recharge rate couldn’t keep up with the Dreamcatcher’s draw.

Back to the drawing board.

Zoltan suggested I look at https://www.easyacc.com/en/226-power-bank which he thinks can run the Dreamcatcher and stay charged. He estimates Dreamcatcher runs at a max dc draw of 900 mA.

On the other hand, I just ordered an Adafruit PowerBoost 1000 Charger - Rechargeable 5V Lipo USB Boost @ 1A - 1000C from https://www.adafruit.com/product/2465. Small as it is, it will supply 1 amp dc at 5 v, and uses a LiPo battery (so I can use my Alpha Lantern’s Boston Power Swing 5300 pack).

The device appears to function in a similar way that the CHIP did recharging its LiPo. It is sold as an uninterruptable power source (UPS) for computer projects like the Raspberry Pi.

Ken


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#7

I’ve been testing several USB packs I have here as well. The key is that they need to accept 2amps on their input charge port so they can draw more power than the Dreamcatcher is using. Then obviously you need to have something pushing out 2amps to charge them and still power the Dreamcatcher. Most new USB packs, like those Zoltan mentioned, have these specs now. I’m not sure about that LiPo board you linked to though, says it will put out 1a, but what will it take in on its input/charge port?


#8

I have been finding that you need to look for battery packs that specify that they will pass-through. Meaning that if an input is sensed it will do two things… 1-send power to the output and 2-charge it’s battery. These seem hard to find… and a caveat… some will pass-through but then shutdown the output when their internal battery reaches full charge. Others will stop recharging when they reach full charge… and won’t auto start recharging unless disconnected or buttons are pushed. Most of battery packs shut off the output if you plug a charger into the ‘input’. My research was for the possible solar panel to the input of a battery pack that met the above criteria… I have been fooled by advertising.


#9

Ya, I’ve experienced each of mine behaving differently in these respects as well. I was looking for similar solutions a while back for a Pi, found this guy, this does exactly what we’d all like to have: https://www.tindie.com/products/xorbit/lifepo4weredpi3/ It just needs to be ‘hacked’ to work on the Dreamcatcher. Wiring would be easy, not sure about the software side for the auto-shutdown, etc though. Maybe we should start another topic/thread for power supply stuff…


#10

According to Adafruit’s specs, it does not run a device from the battery, but keeps the battery charged for when it is needed to power your device when the USB source drys up. It sounds like the way the CHIP did its LiPo battery charging.

Too bad Outernet didn’t include this capability in the final Dreamcatcher. The first picture (back when) had a JST plug on the board, but the final production unit had removed it.

We’ll see what happens - - I’ll report back after I try it out. The only other thing I’ll have to add is an external switch to break the dc feed into the Dreamcatcher to turn it fully off. I have my gear all buttoned up in an old Alpha Lantern case, so it’s hard to just pull a plug :wink:

Ken


#11

Here’s my ultra simple platform. All nylon standoffs (not to be confused with spacers) - these standoffs have 6-32 threads matching the 6-32 screws - all nylon - I used. Lexan platform. This’ll sit in my living room and I’ll pass a low loss cable thru the wall to a pivoting mount for the antenna outside . More on that later.


#12

Well, the dingalings at Ace hardware were out of shorter nylon screws so I hadda cut 'em (all 8 of 'em) short with a box cutter rolling along the threads to make them short enough to not run into each other halfway in the standoffs. The nylon screws on the bottom serve as bumpers to set it on a table and not scrape the lexan all up. I coulda used the smaller holes as well but not necessary for this. Lexan melts when you use a rotating bit to drill or cut it, so beware, mess ensues! It’s what they had at the aforementioned ill-stocked hardware store. Anyhow done.


#13

I hand (melted/fabbed) some acrylic brackets for the antenna… Sadly, the holes in the antenna do NOT fit 6-32 screws as do the holes in the Dreamcatcher. So… (sigh) I"ll go back and scrounge up some 4-40 nylon screws and nuts at said mediocre hardware store. I’ll drill a hole for a 1/4-20 screw (universal tripod mount) to fit thru the center of the brackets (there are two - you’ll see) as well. Pictures tomorrow.


#14

Here is what I ordered

1byone 24W Foldable Solar Charger amazon B01DBBE18Q

Heloideo 5000mAh Slim Power Bank with AC Adapter amazon B01HI0ICTA

Plastic Enclosure Project Junction Box amazon B0143YWC2W

I am a little worried since someone said 'Don’t stack the antenna on top of the DC" I think due to RFI. Well I had to start somewhere. and PS I found some 2.5mm standoff’s that fit antenna mount holes.

Last minute add: some led light tubes so I can see the SNR lights when setting up the box (hopefully the next couple revision to the skylark will use the snr leds)

see amazon: VCC (Visual Communications) LMC_020_CTP LTP - B01N9FPAXA


#15

5000mah is not likely enough to last you through the night. I’ve been testing a 6000mah pack and I get right around 6 hours out of it using the passive antenna and the on-board LNA. You will need something in the 12000mah+ range or more even, especially considering if you have a cloudy/rainy day, you won’t make it. Plus you need to find out how this battery pack behaves.

  1. Does it allow powering a device while being charged?
  2. Does it kill power to the device when it gets fully charged?
  3. Does it accept 2amps+ on the input so it can charge AND power the device at the same time?
  4. Does the pack power on the device automatically after going dead once it gets power on its input again?

I have only 1 older pack that meets 3 of these 4 criteria, and it doesn’t accept 2amps on the input, so its mostly useless anyway. Any pack I have that takes 2amps on the input either does not automatically power on the device after going dead and getting input current again or doesn’t allow powering a device while its being charged… Let us know what you find with the pack you bought, please. Once we find one that meets all of the above and has enough mah available, everyone will likely go out and buy a bunch. :slight_smile:


#16

good points @unixpunk , I tried powering from a 800ma wal-wart power supply and it would shut itself off as soon as the usb-wifi activated. Has anyone measured it’s current draw? My 2a 5v seem to work.


#17

OK… after some cursing, and so on, a bit of a lashup, but hey, now it works! I can point it, etc. I need to duct tape the gorilla tripod down to the workmate (workmate designed by guy who designed the Lotus Elan or one of 'em at least.) . I had to add an extension to the wifi or it wasn’t strong enough for the basement (behind the concrete in one of the pics. I also took my wifi setup in my basement computer and hung it closer to the wall and up higher. The combo gave excellent two-way …

So you see, I bent those shapes so I cleared the back of the Antenna thingie. I had to offset the hold/mount for the 1/4-20 as it was such a short screw, but after that, even offset, with a universal pivot on this tripod, no biggie. I had to use metal screws for the antenna as 4-40s are not available at the hardware store in nylon (I DID order some, didn’t wanna wait). The bracket is acrylic. You cut it by scoring like glass (I used a box cutter) then extending over the edge of a table and placing a flat large object on top of the acrylic ON the table and whapping the overhanging edge with the side of your hand… It’s brittle yet bends easily under heat. Drilling is a pain. Sawing with a hacksaw to trim edges of (note I trimmed the corners so they didn’t hang out) isn’t so bad. I bent the acrylic over the edge of a table after heating with one of those cheapo torches run with butane (using butane lighter refillers). Enjoy!


#18

Update on Adafruit Powerboost 1000C

The Adafruit Powerboost 1000c does not work with the Dreamcatcher. My configuration was to connect a Boston Power Swing 5300, a 2.4 amp USB wall wart, and the Dreamcatcher. If you start with a fully charged LiPo, the unit will drive the Dreamcatcher and float charge the LiPo fine.

If you run down the LiPo by disconnecting external power for 40 minutes, the Dreamcatcher runs fine. But running the Dreamcatcher while then recharging the LiPo from the Powerboost 1000C sheds the Dreamcatcher load.

It was worth trying, so I can understand Outernet engineering a solution might be very difficult to do. I’m more inclined to use Zoltan’s @zoltan external power pack idea. I know Jim @ac8dg ordered a Heloideo 5000mAh Slim Power Bank that might work (running and keeping the Power Bank charged so the Dreamcatcher stays operative), so I’m looking forward to his report. Ken


#19

Hi Ken,

As a frequent traveler don’t forget the lithium battery restrictions, looks like the sweet spot is somewhere 100Wh (at least at KLM) This means 20Ah x 5V = 100Wh, for example the 20.000mAh EasyAcc would be compliant to this.
https://www.klm.com/travel/hu_en/images/Lithium-batteries-on-KLM-aircraft_tcm597-671555.pdf


#20

Update: Last night I added some duct tape to secure the tripod to the table. I’m going to let the whole system run for the next several days.