You can find 3D models as 3D-PDF for JST XH connectors on the JST website.
However, in order to obtain STEP or IGES models, you have to look on the jst-mfg.com site.
01
Jan
2023
31
Dec
2022
How to check a KiCAD footprint against KLC (KiCAD library conventions)
First, clone kicad-library-utils using
git clone https://gitlab.com/kicad/libraries/kicad-library-utils.git
Then, run the check script against your footprint – Connector_RJ.pretty/RJ9_Evercom_5301-4P4C.kicad_mod in this example – using
~/kicad-library-utils/klc-check/check_footprint.py -vv Connector_RJ.pretty/RJ9_Evercom_5301-4P4C.kicad_mod
You might need to adjust the path to kicad-library-utils accordingly.
This will provide colored output on the command line such as
Checking footprint 'RJ9_Evercom_5301-4P4C':
Violating F5.2 - https://klc.kicad.org/footprint/f5/f5.2/
Fabrication layer requirements
Value Label Errors
Violating F7.2 - https://klc.kicad.org/footprint/f7/f7.2/
For through-hole components, footprint anchor is set on pad 1
Pad '1' not located at origin
Violating F9.1 - https://klc.kicad.org/footprint/f9/f9.1/
Footprint meta-data is filled in as appropriate
Value label '5301-4P4C' does not match filename 'RJ9_Evercom_5301-4P4C'
Violating F9.3 - https://klc.kicad.org/footprint/f9/f9.3/
Footprint 3D model requirements
3D model file path missing from the 3D model settings of the footprint
29
Dec
2022
Where to find cheap X5R/X7R capacitors?
LCSC is typically the cheapest vendor for buying reels. Note, however, that the shipping fee is rather expensive (around 35€ to Germany), so it will only be worth the saving if you order larger quantities of components.
10nF0603 50V: 4000pcs of Yageo CC0603KRX7R9BB103 for5,20€100nF0603 50V: 4000pcs of CCTC TCC0603X7R104K500CT for4,80€
28
Dec
2022
How to backup docker-compose PostgreSQL database using bup
This command will generate a PostgreSQL dump using pg_dump and immediately feed it into bup split (without creating an intermediate file) for backup.
It assumes that .env contains a line
POSTGRES_USER=myuser
so that the sc
Local .bup variant
Set BUP_DIR
export BUP_DIR=/var/bup/my-database.bup
source .env && docker-compose exec -u postgres -T postgres pg_dump -U${POSTGRES_USER} | bup -d $BUP_DIR split -n mydb-pgdump.sql
bup remote variant
export BUP_DIR=/var/bup/my-database.index.bup
export BUP_REMOTE=bup-server:/bup/my-database.bup
source .env && docker-compose exec -u postgres -T postgres pg_dump -U${POSTGRES_USER} | bup -d $BUP_DIR split -r $BUP_REMOTE -n mydb-pgdump.sql
28
Dec
2022
Headscale docker-compose config for Traefik HTTPS reverse proxy
This config is based on our previous post How to setup headscale server in 5 minutes using docker-compose and our Traefik configuration with Cloudflare wildcard certs (see Simple Traefik docker-compose setup with Lets Encrypt Cloudflare DNS-01 & TLS-ALPN-01 & HTTP-01 challenges)
version: '3.5'
services:
headscale:
image: headscale/headscale:latest
volumes:
- ./config:/etc/headscale/
- ./data:/var/lib/headscale
ports:
# - 27896:8080
- 9090:9090
- 3478:3478/udp
command: headscale serve
restart: unless-stopped
depends_on:
- postgres
labels:
- "traefik.enable=true"
- "traefik.http.routers.headscale.rule=Host(`headscale.mydomain.com`)"
- "traefik.http.routers.headscale.entrypoints=websecure"
- "traefik.http.routers.headscale.tls.certresolver=cloudflare"
- "traefik.http.routers.headscale.tls.domains[0].main=mydomain.com"
- "traefik.http.routers.headscale.tls.domains[0].sans=*.mydomain.com"
- "traefik.http.services.headscale.loadbalancer.server.port=8080"
postgres:
image: postgres:14
restart: unless-stopped
volumes:
- ./pg_data:/var/lib/postgresql/data
environment:
- POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
- POSTGRES_DB=${POSTGRES_DB}
- POSTGRES_USER=${POSTGRES_USER}
28
Dec
2022
How to fix Oracle Cloud VNC connection: no matching host key type found. Their offer: ssh-rsa
Problem:
When trying to connect to your Oracle Cloud instance using VNC using Linux, you’ll get a command like
ssh -o ProxyCommand='ssh -W %h:%p -p 443 ocid1.instanceconsoleconnection.oc1.eu-frankfurt-1.antheljtwxs32nycl7rgwekcj4t2pecwwcsm7mgzy5c3tt3iiovq564wubta@instance-console.eu-frankfurt-1.oci.oraclecloud.com' -N -L localhost:5900:ocid1.instance.oc1.eu-frankfurt-1.antheljtwxs32nycblplzbuamqsqbi4ipz377f3qhs6a4tdh74j673jfsjtq:5900 ocid1.instance.oc1.eu-frankfurt-1.antheljtwxs32nycblplzbuamqsqbi4ipz377f3qhs6a4tdh74j673jfsjtq
but you see error messages like
Unable to negotiate with 130.61.0.255 port 443: no matching host key type found. Their offer: ssh-rsa
Solution:
Add the following text at the end of your ~/.ssh/config and retry:
Host *
HostkeyAlgorithms +ssh-rsa
PubkeyAcceptedAlgorithms +ssh-rsa
This will make SSH accept RSA host keys.
28
Dec
2022
Where to find cheap tactile switches / push buttons?
LCSC has a really cheap all-metal push button for only 0.0129€/pc @50pc
It works with the KiCAD 6.0
Button_Switch_SMD:SW_SPST_TL3342
footprint and the KiCAD 6.0
Switch:SW_Push
symbol.
28
Dec
2022
Where to find Taiyo Yuden NRS5040 / NRS5050 STEP 3D models?
You can find the 3D models on the Taiyo Yuden website.
28
Dec
2022
How to take a remote screenshot on the Raspberry Pi
You can login to your Raspi using ssh -CX pi@IPADDRESS and then run
DISPLAY=:0 scrot screenshot.png
to take a screenshot of the display that is currently attached. After that, use
feh screenshot.png
(due to ssh -CX this will display the image locally on your Linux desktop) or copyscreenshot.png to your local computer using scp, rsync, WinSCP or any other tool.
This is useful for debugging what is happening on your display.
28
Dec
2022
How to randomize image order using the feh image viewer
feh is a modern image viewer which you can parameterize on the command line.
Use the -z flag (or --randomize) to randomize the order of the images.
27
Dec
2022
How to get IP address of a running docker-compose container
This will get the IP address of a running docker-compose container for the mongoservice.
docker inspect $(docker-compose ps --format json | jq -r 'map(select(.Service=="mongo"))[0].ID') --format '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}'When you use this in shell scripts, it’s often convenient to store the IP address in a variable:
export MONGO_IP=$(docker inspect $(docker-compose ps --format json | jq -r 'map(select(.Service=="mongo"))[0].ID') --format '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}')which you can then use as $MONGO_IP.
For more details on how this works, see the following posts:
- How to list just container names & IP address(es) of all Docker conatiners
- How to get container name of docker-compose container
27
Dec
2022
How to get container name of docker-compose container
Lets’s assume the directory where your docker-compose.yml is located is called myservice
If you have, for example, a docker-compose.yml that declares a service mongo running MongoDB, docker-compose will call the container mongo or mongo-1.
However, docker itself will call that container myservice-mongo-1.
In order to find out the actual docker name of your container – assuming the container is running – use the following code:
docker-compose ps --format json | jq -r 'map(select(.Service=="mongo"))[0].Name'
This uses docker-compose ps to list running containers, exporting some information as JSON, for example:
[{
"ID": "2d68b1c1625dbfb41e05f55af0a333b5700332112c6c7551f78afe27b1dfc7ad",
"Name": "production-mongo-1",
"Command": "docker-entrypoint.sh mongod",
"Project": "production",
"Service": "mongo",
"State": "running",
"Health": "",
"ExitCode": 0,
"Publishers": [
{
"URL": "",
"TargetPort": 27017,
"PublishedPort": 0,
"Protocol": "tcp"
}
]
}]Then we use jq (a command line JSON processor) to a) select only the entry in the list of running containers where the Service attribute equals mongo, b) take the first one using [0] and get the Name attribute which stores the name of the container.
Example output
$ docker-compose ps --format json | jq -r 'map(select(.Service=="mongo"))[0].Name' myservice-mongo-1
27
Dec
2022
jq: Select entry from list of objects for which key equals value
This example selects, given a list of JSON entries, all entries where .service equals "mongodb" (i.e. {"service": "mongo"}:
jq 'map(select(.service=="mongo"))'
27
Dec
2022
How to setup bup-server on Synology NAS using docker
This guide shows you how to create a bup server. This is based on our previous post How to setup a “bup remote” server in 5 minutes using docker-compose but uses Synology’s built-in Docker GUI instead of docker-compose.
First, create two shared directories bup-backups (which will store the backups itself) and bup-config )which will store the dropbear SSH server configuration, that is SSH host keys and authorized client keys).
Alternatively, you can also use sub-directories of existing shared directories, but I’d like to keep them separate.
Then create a new Docker container by opening Docker -> Container, clicking Create and follow these steps:
Download ulikoehler/bup-server:lastest
Create a new container from the image
Map out port 2022 (bup server SSH port)
You can choose any other port in Local Port but keep the Container Port the same.
Map the volumes
As we said before, any directory will do. Create the sub-directories as needed.
Creating the SSH keys
On your local linux computer, create a SSH key using
ssh-keygen -t ed25519 -f id_bup -N ""
Upload id_bup and id_bup.pub to the bup-config shared folder.
Furthermore, copy id_pub.pub to bup-config/dotssh/authorized_keys.
After that you can startup the container.
Test the login
Use
ssh -i id_bup -p 2022 bup@[AS IP address]
to try to connect to your NAS.
Troubleshooting
In case connecting via SSH does not work, most likely the issue is with your public/private key and/or your authorized_keys file. Check if it is in the right directory (/home/bup/.ssh/authorized_keys on the container). Also check the logs of the Docker container.
26
Dec
2022
How to set screen size for UEFI VMs on XCP-NG
The following sequence allows you to enter the UEFI setup and set the screen size. It does not work for VMs running BIOS!
- Open the VM’s console
- Start the VM
- Immediately start pressing
F2repeatedly until you see the UEFI setup screen:
- Enter the
Device Manager
- Enter
OVMF Platform Configurationand select the screen resolution
- Exit by pressing
ESCand selectYto save the changes. Continue pressingESCuntil you are at the start screen. - Now select
Resetand wait for the OS to boot. You need to selectResetbecause the change will only be effective after the next complete reboot.
26
Dec
2022
Raspberry Pi libcamera VLC recording to H.264 (1920×1080)
On the Pi, run
libcamera-vid -t 0 --width 1920 --height 1080 --codec h264 -o out.h264
This will record Full-HD video (1920×1080) to out.h264
26
Dec
2022
How to list available cameras on Raspberry Pi (libcamera)
Use this command to list all available cameras:
libcamera-still --list-cameras
Example output:
$ libcamera-still --list-cameras
Available cameras
-----------------
0 : imx477 [4056x3040] (/base/soc/i2c0mux/i2c@1/imx477@1a)
Modes: 'SRGGB10_CSI2P' : 1332x990 [120.05 fps - (696, 528)/2664x1980 crop]
'SRGGB12_CSI2P' : 2028x1080 [50.03 fps - (0, 440)/4056x2160 crop]
2028x1520 [40.01 fps - (0, 0)/4056x3040 crop]
4056x3040 [10.00 fps - (0, 0)/4056x3040 crop]
26
Dec
2022
How to fix Raspberry Pi OS raspivid: command not found
Problem:
When trying to run raspivid on Raspberry Pi OS Lite, you will see the following error message:
bash: raspivid: command not found
Solution:
In recent versions of Raspberry Pi OS, raspivid has been replaced by libcamera-vid. Therefore, use libcamera-vid instead of raspivid.
26
Dec
2022
How to allow remote SMB/CIFS access to /home/pi on the Raspberry Pi
First, install samba using
sudo apt -y install samba
then append the following to /etc/samba/smb.conf
[pi] comment = pi path = /home/pi writeable = yes browseable = yes public = yes create mask = 0644 directory mask = 0755 force user = pi
and finally restart samba:
sudo systemctl restart smbd
Now your /home/pi will be accessible via SMB (including write access).
25
Dec
2022
How to setup & use WordPress REST API authentication using Python
WordPress authentication plugin setup
First, install the WordPress REST API Authentication wordpress plugin, which you can find by searching for WordPress REST API Authentication:
Then you need to open the plugin configuration page. Open Plugins in the WordPress admin panel, locate the WordPress REST API Authentication plugin and click Configure
Select Basic Authentication:
Then click Next on the top right:
and click Finish on the next page:
Setup in Python
Assuming you have a WordPress user admin with password abc123 we can modify our code from How to get WordPress posts as JSON using Python & the WordPress REST API in order to query a non-public endpoint:
import requests
import base64
# Compute basic authentication header
auth_header = b"Basic " + base64.b64encode(b"admin:abc123")
# posts is a list of JSON objects, each representing a post
posts = requests.get("https://mydomain.com/wp-json/wp/v2/posts",
params={"context": "edit"},
headers={"Authorization": auth_header}).json()