The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Tag: Improvements

Making the world a better place, one piece at a time

Pi-Hole with DNS-over-HTTPS
With none other than Troy Hunt recommending Pi-Hole, I got a Round Tuit:
```
unzip 2018-06-27-raspbian-stretch-lite.zip -d /tmp
sudo dcfldd status=progress bs=1M of=/dev/sde if=/tmp/2018-06-27-raspbian-stretch-lite.img
```
Raspbian now arrives with ssh disabled, so the first boot requires a keyboard and display:

Pi-Hole first boot wiring

Then do some configuration required to get a fresh Raspberry Pi ready for remote access:
```
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install screen iotop
sudo raspi-config   # enable ssh
ssh-keygen -t rsa
cd ~/.ssh
cp -a /my/public/key authorized_keys
chmod go-rwx authorized_keys
cd
sudo nano /etc/ssh/sshd_config  # unusual port, no root login, etc
sudo service ssh restart
```
As the good folks at Pi-Hole say, “Piping to bash is controversial, as it prevents you from reading code that is about to run on your system.” I took a look, it’s beyond my comprehension, so just get it done:
```
curl -sSL https://install.pi-hole.net | bash
```
Configure Pi-Hole:
- Static IP: 192.168.1.2/24
- DNS using, say, Cloudflare’s 1.1.1.1
- DHCP turned off, which is the default
Configure the router’s DHCP to hand out the Pi-Hole’s IP, with, say, 9.9.9.9 as a backup.

Boot a few random PCs and whatnot to verify it works as expected, which it did the second time around, thus this particular post.

Install the Cloudflare Argo Tunnel dæmon, approximately according to suggestions:
```
mkdir Downloads
cd Downloads/
wget https://bin.equinox.io/c/VdrWdbjqyF/cloudflared-stable-linux-arm.tgz
tar zxvf cloudflared-stable-linux-arm.tgz
sudo mkdir /opt/cloudflare
sudo cp cloudflared /opt/cloudflare/
```
Start the daemon from within a screen session, also as suggested:
```
sudo /opt/cloudflare/cloudflared proxy-dns --port 54 --upstream https://1.1.1.1/.well-known/dns-query --upstream https://1.0.0.1/.well-known/dns-query
INFO[0000] Adding DNS upstream                           url="https://1.1.1.1/.well-known/dns-query"
INFO[0000] Adding DNS upstream                           url="https://1.0.0.1/.well-known/dns-query"
INFO[0000] Starting metrics server                       addr="127.0.0.1:37777"
INFO[0000] Starting DNS over HTTPS proxy server          addr="dns://localhost:54"
```
Contrary to the suggestions, you can configure Pi-Hole to use the DoH tunnel (or whatever it’s called) by tweaking its upstream DNS configuration:

Pi-Hole – Cloudflare DNS config

Then set up systemd to start the daemon automagically:
```
sudo nano /etc/systemd/system/dnsproxy.service
```
Because I put the daemon in /opt/cloudflare, that file differs slightly from the suggestion:
```
[Unit]
Description=CloudFlare DNS over HTTPS Proxy
Wants=network-online.target
After=network.target network-online.target

[Service]
ExecStart=/opt/cloudflare/cloudflared proxy-dns --port 54 --upstream https://1.1.1.1/.well-known/dns-query --upstream https://1.0.0.1/.well-$
Restart=on-abort
 
[Install]
WantedBy=multi-user.target
```
And then It Just Worked.

Controversies over the ethics of ad and tracker blocking will go nowhere here, as I’ve cleaned out enough Windows machines to have absolutely no sympathy with the unholy spawn of adtech (not just the company, which I didn’t know existed until just now, but, yeah, them too).
2018-10-02
Brush Clearing

Some recent brush-clearing along our usual bicycle routes:

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The bushes with oval leaves are Blackthorn, of which Wikipedia says “The shrub, with its savage thorns, is traditionally used […] to make a cattle-proof hedge.” They’re commonly found along the untamed border of Rt 376, as well as the rail trail.

It’s more effective than expecting my tax dollars to wake up and get to work …

2018-09-30
Wyze Cam vs. Xiamoi-Dafang Hacks

The Wyze Cam is a surprisingly inexpensive camera firmly lashed to the Wyze app, with no provision for ordinary IP camera streaming. It seems to be a generic camera with custom firmware and, unsurprisingly, one can commandeer the bootloader with different firmware from a MicroSD card, thereby adding missing functions and suppressing undesired actions.

Oddly, buying a genuine Wyze Cam directly from Wyze isn’t significantly more expensive than a generic from the usual eBay / Amazon sellers. Bonus: the legit camera arrives next week rather than in a month or two.

I found one of my few remaining 2 GB MicroSD cards, formatted it with a 512 MB (!) FAT32 partition (per the suggestions), set up the “custom firmware” bootloader, and installed it with no issues.

Installing the new firmware requires copying a directory tree, configuring the WiFi SSID and password in the usual wpa_supplicant, and rebooting. Works fine and, yeah, the camera now runs Linux.

I told the router to assign a known IP address to the camera’s MAC address, set up port forwarding for port 8554 to that IP address, put the camera against the storm window in the kitchen, and rebooted everything to get it working:

Wyze Cam in kitchen window

Unfortunately, while it works more-or-less well with browsers on the local network, it’s apparently inaccessible from outside. The router manages a DDNS name-to-IP mapping to make itself findable, the port is open, the forwarding seems correct, no image data arrives to browsers outside, and they eventually time out.

Changing to port 8080 doesn’t help, nor does using MJPEG instead of H264 encoding.

Even more unfortunately, the router doesn’t do hairpin connections (inside to outside to inside), so I can’t debug this mess from the Comfy Chair.

This is a placeholder for what I’ve done while I accumulate more knowledge …

2018-09-27
MPCNC: Re-Relocated Probe Camera

Although the camera doesn’t hit anything, it seemed entirely too exposed out in front:

MPCNC – relocated camera – front view

So I moved it to the back, where I can’t see it and maybe won’t clobber it:

MPCNC Re-Relocated USB Camera

The camera sensor is now almost exactly aligned with the XY axes, so the goofy rotation is gone and the offsets look better:

bCNC – Rear-mount Camera Probe Config

The size of the “10 mm” inner circle at the crosshair depends on the target distance, so it’ll be smaller for surfaces clamped onto and thus rising above the table. Depending on how much that matters, I can tweak the camera focus and scale factor to make the answer come out right.

The setup at the home position looked like this from a different perspective:

MPCNC – Rear-mounted USB Camera

No operational change, just a cleanup.

2018-09-25
Troubles in PC Land

So this happened:

Dell Optiplex – SSD failure

As far as I can tell, the Crucial M5500 SSD in that PC (an off-lease Dell Optiplex 760) stopped being a SATA hard drive, although it seems to work OK when jammed in a USB adapter.

So I picked up a new-to-me Optiplex 9020 with Windows 8.1 on an SSD, shrank the partition, tried to install Xubuntu 18.04, fat-fingered the UEFI password dance, reinstalled Windows from the SSD’s recovery partition, and got this display after a while (clicky for more dots):

Dell Optiplex – recovery disk stall

After letting it stew in its own juices during supper, I forced it off (pushed the power button until it died), restarted, got through the UEFI dance, and it now seems All Good. I made recovery DVDs (remember DVDs?), both before and after the fumbled Xubuntu installation, but didn’t need them.

I expect we’ll never boot Windows 8.1 again, but it’s there Just In Case.

2018-09-21
Streamripper Setup
The Intertubes occasionally clog up while streaming low-bit-rate audio, for no reason I can fathom, leading to discontent in the User Community when it affects quiet classical music played in the dead of night. Given that the stream from far-off Switzerland consists entirely of public-domain performances, I set up Raspbian Lite on a headless Raspberry Pi 1 Model B+ in a spot where it won’t be disturbed:

Raspberry Pi 1 for streamripper

Connecting to the Pi with a screen session, so as to allow disconnection & reconnection without anguish, I fired streamripper thusly:
```
streamripper http://relay.publicdomainproject.org/classical.mp3.m3u -xs2 -o larger -u "MPlayer2" -m 30 -r -R 6 --with-id3v1
```
The -r -R 6 options set up a relay stream on http://ripper.local:8000 for the benefit of my local streamers, so only one trickle of bits crosses the Atlantic.

The total CPU load amounts to a percent or two, tops, so a single-core 700 MHz Pi has no trouble keeping up.

Because streamripper slings bits in more-or-less real time, the local servers don’t get any track title data when they start up, so the OLED display doesn’t update immediately. This is less of a problem than you might think, as we’re generally not hanging on the display to find out exactly which Vivaldi bassoon concerto is playing.

Given a suitable collection of tracks, I’ll set up an icecast server as the classical music “station” for the streamers, but that’s an adventure for another day. I also want to splice separate movements back into continuous symphonies, the way they’re suppose to be heard.
2018-09-20
Refurbished LED Panels

A recent Squidwrench meeting produced a treasure trove of discarded LED lighting, including a shoplight-style fixture in a narrow, finned aluminum extrusion. It was in “known-bad” condition, so I extracted the four LED panels, connected each one to a widowmaker cord, and determined I had two good ones, a mostly working one sporting some dead LEDs, and a corpse.

The working panels showed the power supplies produced about 19 V across two parallel strings of six LEDs, with each string running at 350 mA for a total of 700 mA = 13 W. I wired up a quartet of 6 Ω power resistors to check out the power supplies from the suspect panels:

LED Panel – power supply test setup

The supply in the background is truly dead. I can’t tell whether it killed the LEDs or the gaggle of failing LEDs dragged it down with them.

Some multimeter probing revealed enough live LEDs to restore the partially working panel. A rather sweaty interlude at the SqWr hot-air rework station transplanted the good LEDs, whereupon combining it with the live supply gave me a third fully functional panel:

LED Panel – restored

I did the test firing in the Basement Laboratory, because I’m nowhere near crazy enough to deploy a widowmaker line cord on the SqWr Operating Table in public.

I bandsawed the last working LED from the gutted donor panel:

LED Panel – single LED test

The SMD LEDs mount on traces applied to and electrically insulated from the aluminum sheet, so unsoldering them required way more heat than you (well, I) might expect at first glance. A snap-on condenser lens over each LED concentrates the light into a nice cone, producing a narrow sheet of light from each panel.

The elaborate aluminum extrusion seems much too heavy for the individual panels, but those open-frame supplies definitely need more than casual protection. Now that LEDs are more common than when these panels came off the assembly line, I should probably replace the supplies with enclosed constant-current drivers and be done with it.

2018-09-18