I wanted to do some laser cutting so I thought I will just order a laser and mount it to my 3D printer. I ordered one with most orders on ali: https://www.aliexpress.com/item/32562052620.html . When it came, the fun started.
Continue reading Ender 3 as a laser cutterAll posts by danman
OpenShift 4: Automatic LDAP group synchronization
If you need to use LDAP for authentication in OpenShift 4, the documentation is pretty clear and everything works nicely [1].
But if you need to grant privileges based on LDAP groups [2], the situation gets complicated.
The synchronization from [2] works ok but you need to run it manually. I was searching for an automated solution and I have found a definition [3] which works for OpenShift 3.x so I updated it work with OpenShift 4 and here it is [4]:
CometBlue teardown
Chips used:



Links
- https://github.com/xrucka/cometblue
- https://github.com/Hy3n4/ha-cc-cometblue
- https://www.torsten-traenkner.de/wissen/smarthome/heizung.php
- https://github.com/esphome/feature-requests/issues/485
- https://github.com/GrumpyMeow/esphome-components
- https://github.com/gnbl/sparmatic2011
- https://www.mikrocontroller.net/articles/Sparmatic_Heizungsthermostate
- https://blog.renekliment.cz/2015/11/termostaticka-hlavice-z-lidlu-s-atmega-169.html
- https://github.com/MrKrabat/Comet-Blue-Thermostat
Eavesdropping HTTPS with Haproxy
Sometimes one needs to debug a protocol problem between client and server but what if the connection is encrypted with SSL/TLS? You can use this trick to reveal the unencrypted traffic.
Continue reading Eavesdropping HTTPS with HaproxyAdapter powered NX-300 camera
My wife owns a Samsung NX-300 camera and I wanted to use it for longer periods without needing to charge batteries round and round. Unfortunately, this camera can use its microUSB port only for charging – it doesn’t work without a battery and doesn’t charge when powered on. So I had to create a dummy battery.
Continue reading Adapter powered NX-300 cameraAbout adding a static route to my DOCSIS modem
You may think this is an easy task but let’s find out. One would expect such functionality in a web interface …

… but no, it’s not there. So what’s next? Let’s hack it!
Continue reading About adding a static route to my DOCSIS modemZidoo X8 recovery
Short guide how to recover from completely wiped eMMC in case you have full eMMC backup and a bootlog from working device.
Continue reading Zidoo X8 recoveryMy socat examples
Transport serial port over network
The other end may be provided by ser2net
socat -d -d pty,link=/dev/ttyUSB99,echo=0,perm=0777 TCP4-CONNECT:192.168.0.254:5000
Emulate two connected serial ports
socat -d -d pty,link=/dev/ttyUSB98,echo=0,perm=0777 pty,link=/dev/ttyUSB99,echo=0,perm=0777
Some multicast examples here: https://blog.danman.eu/using-socat-for-multicast-receiving-and-proxying/
Testing chinese FRAMs
I’m planning to use FM24CL16 EEPROMs in some projects. These are simple I2C EEPROMs but based on FRAM technology so they should last 10^14 of writes while typical 24Cxx chips only last one million. They are much cheaper on aliexpress than at my local distributor so I ordered 5pcs from this seller for about 40 cents each. Since my local distributor sells them 5 times more expensive I was a little bit suspicious if these are legit parts so I decided to test them.
Continue reading Testing chinese FRAMsPlaying with CAN bus
I got inspired by comma.ai – it’s a HW device which will drive your car, pretty much like Tesla does but for a fraction of it’s price. For this, it needs to connect to CAN bus of your car. My current car cannot be driven by wire but it has some simple CAN buses so I decided to have a little play with one of them, just to explore the technology. Continue reading Playing with CAN bus