Another day working a bit for my SA818 radio node project. Today I tried active cooling with a 5V fan driven from RPIs 5V rail and controlled from GPIOs with a MOSFET (2N7002).
Python: not enough values to unpack
While creating some code for the Arduino and C struct post, I ran into this issue “not enough values to unpack” and this has to do with Python’s struct format.
Alternative to ssh-copy-id on windows
Lately I am doing a lot of development on Raspberry Pi systems and I use Visual Studio Code Remote Development. This is a neat feature because it allows me to connect from the same platform to multiple systems at once and work in parallel if I need. Visual Studio Code includes a full featured integrated […]
Using lsof
lsof command can show which processes are using which resources. This is extremely useful for troubleshooting. Basic syntax is: Without arguments, it lists all open files on the system (requires root privileges). Common Use Cases and Examples: Find which process is using a file: Find which process is using a port: The above command Lists […]
Raspberry Pi serial interface issues
There is a problem I forgot to take care before creating the custom image for my radio node project. Programming SA818 module via Raspberry Pi’s UART interface cannot be done unless the UART interface is released from any interaction in console mode. I was banging my head for hours because of sustained DMOERROR message for […]
Cloning a Raspberry Pi SD card
Recently I had to make a bootable SD card for a Raspberry Pi Zero and I faced some issues. I thought to write some hints on how to properly clone and shrink a Pi image on an SD card. Here’s how you can create a compressed ISO (or disk image) from your Raspberry Pi SD […]
How to check the hardware version
Here are some handy commands that can be used to check the hardware version on a Linux-based machine.
Why is journalctl -b -1 not working
Recently I hit a blocker when using journalctl -b -1 did not work. Using the flags ended up in error
NetworkManager connection priority
I recently ran into an issue with my Raspberry-based radio node. I tried to connect to some othet WiFi access points and I realized that I had no idea how to set connection priorities if I have multiple candidates for connection. I was used with wpa-supplicant way of doing things which was just to add […]
I2S Raspberry Interface (4)
More work today. Some wires got loose and I did some experiments with .asoundrc and ALSA settings. I added a 39 Ω ballast resistor on SDIN and SDOUT lines and put a ferrite core on both wires. The radio node works as expected, absolutely no issues with one exception, a periodic pop that is audible […]
I2S Raspberry Interface (3)
Update July 11, 2025 Some thoughts and tasks today. The project is the same I2S interface.
Significant Svxlink power consumption
While testing my I2S project I ran into some boot issues on the Raspberry Pi 4 host. For what seemed to be some unknown reasons the boot process was completely chaotic, sometimes running well, sometimes hanging. I banged my head for some time looking for a solution until it came to my mind to change […]
I2S Raspberry Interface (2)
Update September, 2024. Activities and notes while developing the I2S interface for my radio node.
I2S interface for Raspberry Pi (1)
Today I managed to connect the Digilent Pmod I2S2 to a Raspberry Pi 4 and have all frequencies generated. This is part of an older project that I left abandoned for a while: a radio node built on Raspberry Pi and using Svxlink. As known, Raspberry boards do not have a proper audio interface and […]