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Battery powered, wifi connected Kiwi useful for portable installations and antenna system tests.
Rob Robinett
This week I plan to use this system to probe the RF distribution system at KFS to find out where the NW antenna signal is losing 20+ dB of RF signal strength. But more generally ,this setup is useful in antenna testing where you can eliminate all the RFI introduced by ground loops and other mechanisms in the RF transmission system.
Here is my portable Kiwi system running off a 14.8 LiPo battery which feeds a buck converter which outputs 5V to the Kiwi. The unmodified Kiwi powers the GL.inet 300M "Yellow Thing" (YT) through the Kiwi's USB-A port which is connected to the microUSB power port of the YT. The unmodified YT's USB-A comm port is connected to the microUSB port of the Kiwi through a second USB adapter cable, and the Kiwi appears to the YT as an ethernet device with static address 192.168.7.2
When the laptop is wifi attached to the YT Access Point service, the laptop can access the Kiwi by opening browser to http://192.168.7.2:8073/
I have also configured the YT to at the same time connect as a Wifi client to my home Wifi network where I have configured my DHCP service to assign the YT the address 10.22.22.70. By configuring the YT to forward its wifi port 10.22.22.70:8073 to the Kiwi at 192.168.7.2:8073, I can access the Kiwi from any device on my home LAN at http://10.22.22.70:8073. In this installation the YT is in the same room as my Wifi router, so there is only one wifi connection between the Pi on my home LAN and the Kiwi and there are no dropped packets when the Pi pings the YT at 10.22.22.70.
A WD Pi can use Wifi to attach to the YT and through it access the Kiwi at 192.168.7.2:8073, or the Pi can be ethernet connected to my LAN and access the Kiwi at 10.22.22.70:8073. Since it is my goal to remove all ground loops and LAN-induced RFI, I don't use either of the LAN ports on the YT. While no pings are lost by the Pi when it is physically near the YT, as the distance between them grows there will be a point when pings start to be lost. That will be the max useful distance between the Kiwi+YT and the Pi.
This configuration makes it simple to configure and test the portable Kiwi setup and then carry it out to the field where the Pi and Laptop can wirelessly access the portable Kiwi + YT. Tether your laptop to your cell phone and it is possible for WD on the Pi to record the spots it is gathering to wsprnet.org and wsprdaemon.org. When in the field, if there is no Internet connection for the WD Pi then WD will cache the spots and upload them when it next has internet access.
Glen reminds me that the microUSB connector on the Kiwi is *very* fragile, so don't stress it!
Rob
Glenn Elmore
Good eyes Joe. Yes there is and is the reason I ran power on the same, single cable to the YT along with the data. It's a more complex mod though, requiring addition of a 0 ohm jumper on the BB and a jumper inside the YT. I wrote all this up and posted it somewhere but I've forgotten where.
In practice Rob's two cable solution doesn't seem to introduce much degradation. I hassle him about it anyway. No we have him on two counts, since his credentials have been exposed !
On 11/30/22 16:47, VE7VXO wrote:
Rob
Very clever, but I hate to say this but I can see yout YT SSID and password....
Isn't there going to be a groundloop between the YT and the Kiwi host and client ports? It's only about 20cm in diameter I suppose but still a small loop antenna. Why not power the YT from a USB power stick?
Joe
Just had a look at the yellow thing. Neat little device. Kinda reminds me of an Omega by Onion.io but the onion device is essentially a tiny linux machine running an OpenWRT router. As such it is right up our alley as an infinitely configurable linux based wifi hotspot platform. Check it out.
https://onion.io/omega2-pro/
Disclaimer, I get nothing from these guys other than a few free boards to play with back when they first started making them. They were students at the university where I worked. But I do think they created something rather cool.
Joe
https://onion.io/omega2-pro/
Disclaimer, I get nothing from these guys other than a few free boards to play with back when they first started making them. They were students at the university where I worked. But I do think they created something rather cool.
Joe
Rob Robinett
Hi Joe,
I missed that I was disclosing that password, but fortunately it is unique and completely unrelated to passwords I use elsewhere. Let me know if you can log on to my YT and I'll invite you in for coffee ;=)
The YT cost $20 in Jan 2021 and has risen %50 to $30 today. 50% inflation in 2 years! Fortunately I have 4 of them. They are an excellent OpernWRT platform and thus extraordinarily flexible if you are willing to spend time with them.
Glenn knows how HWE-phobic I am, and I couldn't see that the double cable connection introduced any extra RFI over a single USB cable solution.
Rob
I missed that I was disclosing that password, but fortunately it is unique and completely unrelated to passwords I use elsewhere. Let me know if you can log on to my YT and I'll invite you in for coffee ;=)
The YT cost $20 in Jan 2021 and has risen %50 to $30 today. 50% inflation in 2 years! Fortunately I have 4 of them. They are an excellent OpernWRT platform and thus extraordinarily flexible if you are willing to spend time with them.
Glenn knows how HWE-phobic I am, and I couldn't see that the double cable connection introduced any extra RFI over a single USB cable solution.
Rob
Well I thought it best to let you know so you could change it pronto. Yes the cost of everything is rising eh? But then it seems like every time you turn around you find out we've been lied to. Well maybe that's always been true but just that in this day and age of connectivity and information war its harder for the liars to keep a lid on things? Anyhoo I find it hard to believe anybody's justification for the price hikes. An Omega2 can still be had for about U$D 20.00 if you can find one in stock. The big suppliers still have some. The Omega2 pro is about fifty bucks but has all the battery management and I/O broken out for you so you don't need the docker boards. Probably still cheaper. when you add up the little bits. I was thinking you could run a wsprdaemon server on a battery powered one. I have a couple of omega2's and the mini-docks here. Now that I dug one out I should see if I can get wsprdaemon running on one. They are tiny. Here is one plugged into a minidock to give you a sense of the size. Yup I remebered to obliterate the MAC address b4 uploading this image :)
Rob Robinett
It would be great if the YT or Omega2 could run WD, but there are so many dependencies in WSJT-x that I think it will be a monumental task.
Also, most Pi4b installations are now running out of CPU when processing more than 8 bands, so I would be surprised if the YT and O2 CPU are powerful enough.
Also, most Pi4b installations are now running out of CPU when processing more than 8 bands, so I would be surprised if the YT and O2 CPU are powerful enough.
Lol. Monumental. yeah I'd say so for me especially as a linux newb. I just went to create a wsprdaemon user on the omega and it reported it doesn't have the adduser applet. It didn't initially even have the low level applet useradd. I installed useradd and discovered it is painful to get it to create a new user account properly. Adduser apparently is just a perl script that drives useradd properly but opkg can't install adduser....