Andreas
@afester.bsky.social
Software architect, developer, open source enthusiast, tinkerer, electronics hobbyist
https://www.labcorner.de
https://www.labcorner.de
Working on fixing this PC speaker set - one of the channels had a severe noise, measurements indicate a faulty amplifier IC
May 21, 2025 at 6:39 PM
Working on fixing this PC speaker set - one of the channels had a severe noise, measurements indicate a faulty amplifier IC
At least, seems to be an improvement over Windows 95 😂
(if I remember right this was a system with >1GB RAM though)
(if I remember right this was a system with >1GB RAM though)
April 8, 2025 at 6:00 AM
At least, seems to be an improvement over Windows 95 😂
(if I remember right this was a system with >1GB RAM though)
(if I remember right this was a system with >1GB RAM though)
#Repair session in the #LabCorner 😃
Our toaster did not keep down anymore. Fortunately it only needed some cleaning, magnet and electronics are still intact
Our toaster did not keep down anymore. Fortunately it only needed some cleaning, magnet and electronics are still intact
March 6, 2025 at 8:52 PM
#Repair session in the #LabCorner 😃
Our toaster did not keep down anymore. Fortunately it only needed some cleaning, magnet and electronics are still intact
Our toaster did not keep down anymore. Fortunately it only needed some cleaning, magnet and electronics are still intact
In the past I have used the Thickness tool in #FreeCAD to create cases with a bottom, but today I learned that the bottom is omitted if you also select the opposite face 🙂
February 27, 2025 at 8:39 PM
In the past I have used the Thickness tool in #FreeCAD to create cases with a bottom, but today I learned that the bottom is omitted if you also select the opposite face 🙂
Finished the boot control for my audio station project. When the LED is constantly on, the web server on the #raspberrypi is ready. The only drawback is that the boot process takes quite some time, a lot longer than shown in this video 🫤 - probably need to analyze the boot sequence some day ...
February 24, 2025 at 8:59 PM
Finished the boot control for my audio station project. When the LED is constantly on, the web server on the #raspberrypi is ready. The only drawback is that the boot process takes quite some time, a lot longer than shown in this video 🫤 - probably need to analyze the boot sequence some day ...
#linux shell alias tip:
alias hdump="hexdump -e '\"%08.8_ax: \" 8/1 \"%02X \" \" \" 8/1 \"%02X \" \" \" ' -e '\"|\" 16/1 \"%_p\"\"|\n\"'"
Allows to quickly create hex dumps from the command line:
alias hdump="hexdump -e '\"%08.8_ax: \" 8/1 \"%02X \" \" \" 8/1 \"%02X \" \" \" ' -e '\"|\" 16/1 \"%_p\"\"|\n\"'"
Allows to quickly create hex dumps from the command line:
February 20, 2025 at 8:05 PM
#linux shell alias tip:
alias hdump="hexdump -e '\"%08.8_ax: \" 8/1 \"%02X \" \" \" 8/1 \"%02X \" \" \" ' -e '\"|\" 16/1 \"%_p\"\"|\n\"'"
Allows to quickly create hex dumps from the command line:
alias hdump="hexdump -e '\"%08.8_ax: \" 8/1 \"%02X \" \" \" 8/1 \"%02X \" \" \" ' -e '\"|\" 16/1 \"%_p\"\"|\n\"'"
Allows to quickly create hex dumps from the command line:
Every time I visit the @jetbrains.com website, I get such warm memories ☺️
#retro #borland #turbovision
#retro #borland #turbovision
February 19, 2025 at 9:30 AM
Every time I visit the @jetbrains.com website, I get such warm memories ☺️
#retro #borland #turbovision
#retro #borland #turbovision
The Pi is now also properly shut down when turning off the audio station. The station has an LED which goes off when the power button is pressed, but the station keeps power for some time to perform it's own shutdown - I have connected the LED signal to the shutdown GPIO of the Pi 😃
#electronics
#electronics
February 18, 2025 at 8:43 PM
The Pi is now also properly shut down when turning off the audio station. The station has an LED which goes off when the power button is pressed, but the station keeps power for some time to perform it's own shutdown - I have connected the LED signal to the shutdown GPIO of the Pi 😃
#electronics
#electronics
I have added an indicator LED to the audio station in place of the audio input, which I can not use anymore because this input channel is connected to the raspberry. The LED can be controlled by the raspberry to show various states (especially to indicate that the startup is completed)
February 18, 2025 at 8:07 PM
I have added an indicator LED to the audio station in place of the audio input, which I can not use anymore because this input channel is connected to the raspberry. The LED can be controlled by the raspberry to show various states (especially to indicate that the startup is completed)
Fortunately it's not been a bigger issue. Flashlight working again after replacing the rechargeable battery 🙂
February 11, 2025 at 5:05 PM
Fortunately it's not been a bigger issue. Flashlight working again after replacing the rechargeable battery 🙂
Interesting. This HDMI to DVI adapter does not seem to be just ... an adapter, but seems to have at least some internal circuitry. An old Dell flatscreen did not recognise the signal on its analog VGA input until I removed the adapter from its DVI input 🤔
#vintage #retrocomputing
#vintage #retrocomputing
February 6, 2025 at 8:10 PM
Interesting. This HDMI to DVI adapter does not seem to be just ... an adapter, but seems to have at least some internal circuitry. An old Dell flatscreen did not recognise the signal on its analog VGA input until I removed the adapter from its DVI input 🤔
#vintage #retrocomputing
#vintage #retrocomputing
February 4, 2025 at 8:49 PM
Today's intermediate project: creating some wires to connect individual pins from a pin header to a breadboard
February 4, 2025 at 8:28 PM
Today's intermediate project: creating some wires to connect individual pins from a pin header to a breadboard
Finished mounting the #raspberrypi module in the audio station 🙂
Need to rework the fastening though - the whole module is wiggling when inserting USB plugs 🙄
Need to rework the fastening though - the whole module is wiggling when inserting USB plugs 🙄
January 30, 2025 at 8:57 PM
Finished mounting the #raspberrypi module in the audio station 🙂
Need to rework the fastening though - the whole module is wiggling when inserting USB plugs 🙄
Need to rework the fastening though - the whole module is wiggling when inserting USB plugs 🙄
Finished assembling the #raspberrypi audio module. Fits well into the compact audio station - I had to remove the RCA sockets from the DAC shield though to reduce the overall height.
Now it's time for some metal work I guess 🫣
Now it's time for some metal work I guess 🫣
January 30, 2025 at 7:34 PM
Finished assembling the #raspberrypi audio module. Fits well into the compact audio station - I had to remove the RCA sockets from the DAC shield though to reduce the overall height.
Now it's time for some metal work I guess 🫣
Now it's time for some metal work I guess 🫣
The mounting plate for the #raspberrypi printed well 🙂
I printed it with the mounting domes downwards - this saved a lot of support and reduced the printing time by approx 1 hour.
#3dprinting
I printed it with the mounting domes downwards - this saved a lot of support and reduced the printing time by approx 1 hour.
#3dprinting
January 28, 2025 at 8:12 PM
The mounting plate for the #raspberrypi printed well 🙂
I printed it with the mounting domes downwards - this saved a lot of support and reduced the printing time by approx 1 hour.
#3dprinting
I printed it with the mounting domes downwards - this saved a lot of support and reduced the printing time by approx 1 hour.
#3dprinting
Designing the mounting plate for my #raspberrypi audio project, using #FreeCAD
First time I am using the Fasteners workbench for standard parts like screws and distance nuts
First time I am using the Fasteners workbench for standard parts like screws and distance nuts
January 23, 2025 at 8:05 PM
Designing the mounting plate for my #raspberrypi audio project, using #FreeCAD
First time I am using the Fasteners workbench for standard parts like screws and distance nuts
First time I am using the Fasteners workbench for standard parts like screws and distance nuts
When swapping the connection on either side, the phase shift is gone - and also the noise and the 10 Hz cracking 😃
And, by the way, the signal is now very clean and not cut anymore even when the output level on the #raspberrypi is set to 100%!
#electronics
And, by the way, the signal is now very clean and not cut anymore even when the output level on the #raspberrypi is set to 100%!
#electronics
January 16, 2025 at 7:50 PM
When swapping the connection on either side, the phase shift is gone - and also the noise and the 10 Hz cracking 😃
And, by the way, the signal is now very clean and not cut anymore even when the output level on the #raspberrypi is set to 100%!
#electronics
And, by the way, the signal is now very clean and not cut anymore even when the output level on the #raspberrypi is set to 100%!
#electronics
It turned out that the audio transformers output signal has a 180° phase shift compared to the input when using a straight connection:
January 16, 2025 at 7:46 PM
It turned out that the audio transformers output signal has a 180° phase shift compared to the input when using a straight connection:
Installation of the DAC shield was easy, but then there again was a lot of noise and that 10Hz cracking 😭
January 16, 2025 at 7:43 PM
Installation of the DAC shield was easy, but then there again was a lot of noise and that 10Hz cracking 😭
One thing I noticed while playing a 440 Hz test sound is that the amplitude is cut at the top and the bottom when the raspberry's output level is set to 100%. I am curious how this will look like with the DAC
#electronics
#electronics
January 14, 2025 at 9:25 PM
One thing I noticed while playing a 440 Hz test sound is that the amplitude is cut at the top and the bottom when the raspberry's output level is set to 100%. I am curious how this will look like with the DAC
#electronics
#electronics
I was able to get rid of the major noise by adding two audio transformers to break the ground loop between the #raspberrypi and the amplifier. The 10 Hz cracking is completely gone. Now waiting for the DAC hat to further improve the sound quality 🙂
January 14, 2025 at 9:21 PM
I was able to get rid of the major noise by adding two audio transformers to break the ground loop between the #raspberrypi and the amplifier. The 10 Hz cracking is completely gone. Now waiting for the DAC hat to further improve the sound quality 🙂
Especially annoying are those approx. 10 Hz spikes which cause a constant cracking in the speakers. I ordered some parts today which should improve that, lets see ... 😏
January 13, 2025 at 8:54 PM
Especially annoying are those approx. 10 Hz spikes which cause a constant cracking in the speakers. I ordered some parts today which should improve that, lets see ... 😏
Hooked up the audio output of the #raspberrypi to the amplifier input. Unfortunately this causes a lot of noise - probably caused by a ground loop, but also by the low quality, PWM based audio output of the rasbpi 😞
January 13, 2025 at 8:48 PM
Hooked up the audio output of the #raspberrypi to the amplifier input. Unfortunately this causes a lot of noise - probably caused by a ground loop, but also by the low quality, PWM based audio output of the rasbpi 😞