Author: Admin

JetKVM – Control your serial devices over the network

Control your serial devices over the network

JetKVM is an open-source KVM over IP (Keyboard, Video, Mouse) solution designed for efficient remote management of computers, servers, and workstations. Originally launched as a Kickstarter project, I supported it and received my own device in early 2025. Like many renowned reviewers, I was impressed by the build quality of both the hardware and the software. However, this post is not just another review of the device. Instead, it will describe how you can further extend its functionality to manage even more devices—specifically, how to control your serial devices over a network.

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[Product Review] LC Gigabit Ethernet Port Switcher

Ethernet Port Switch

I recently purchased the LC Gigabit Ethernet Port Switcher from Aliexpress. It appears to be manufactured by Shenzhen LC Technology Co., Ltd, although the product’s web page seems incomplete. Given the electronic nature of the device (specifically for its switching functionality), the ability to switch to a different Ethernet connection using a GPIO is intriguing. This approach can maintain network or device isolation at the hardware level, enabling connectivity only under specific circumstances.

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Reset Raspberry PI using Raspberry PICO or Arduino

While working on my last project, I wanted a way to manually trigger a hardware reset on a Raspberry Pi using a microcontroller such as a Raspberry Pi Pico or Arduino. All recent versions of Raspberry Pi boards have a RUN pin (separate from the GPIO header) that can be used to either reset the device or wake it up from a halt state. The official documentation mentions "Connect to GND to reset" for this specific pin. Using this information, I came up with a very simple schematic that can be used with both 5V and 3.3V logic microcontrollers, utilizing a common NPN bipolar junction transistor (2N3904).

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Network Tap v2 MiTM Edition

Network Tap v2 - MiTM Edition

In my previous post I described how to utilize a Raspberry Pi and capture the traffic from a network device’s SPAN port. In this post, you will find out how to create a proper Network Tap which directly intercepts a network device’s traffic. This is actually a hardware variance of the Man in the Middle Attack (MiTM) which eliminates the requirement for network speed degradation of the Passive Taps.

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Flash CC2531 using a Raspberry PI 4

CC2531USB
Many guides exist describing how to flash a CC2531 USB adapter using a Raspberry Pi instead of a CC debugger. The problem with almost all of those guides is that they are outdated and don’t work on newer devices (specifically with 64 bit architecture). Most of the times the issues have to do with outdated version of wiring PI, or the precompiled for 32 bit devices cc_* binaries (cc_chipid, cc_read, cc_write). In this guide you will learn how to flash CC2531 using a Raspberry PI 4 or any other device with 64 bit architecture OS.

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Raspberry PI 4, 400 and CM custom MAC Address

Today I read this official document (published on September of 2022) which describes how to change the MAC Address of Raspberry PI Devices. Interestingly it describes a different method for Raspberry Pi 4, 400 and CM 4 by editing the EEPROM configuration, using the following command:

sudo -E rpi-eeprom-config --edit

In the configuration file append a new line with the required MAC Address as follows:

MAC_ADDRESS=aa:bb:cc:dd:ee:ff

Save the new configuration (Use Ctrl + X to stop editing, Y to overwrite current file and ENTER to confirm). Upon saving the following message appears:

Pi4_mac_change

Finally, reboot your device in order to apply the new MAC Address. Warning If the device gets IP from a DHCP server, then most probably after the reboot it will be assigned with a new IP address.

This is a different (and simpler) technique from the one which I described in a previous post (which works for all models)

Add SSL/TLS certificate to HomeAssistant’s web interface

Even if your home’s automation is separated from any other network and not internet accessible, it’s always a good practice to use encryption. Failing to encrypt the connection to HomeAssistant’s web interface using an SSL/TLS certificate, results in leaving your password and other data traveling the network as plaintext susceptible to eavesdropping.

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Network Watchdog

Novamostra Network Watchdog

In general a watchdog is a piece of equipment that supervises other systems and resets them in case it detects that those systems are failing, automating the process and increasing the reliability of the system. Network Watchdog is a simple watchdog for monitoring network connectivity and power cycle a device based on ICMP ping replies.

With it’s minimal power requirements, Network Watchdog can use the controlled device’s DC Power source (between 5 and 12 volts) to function, avoiding any additional power requirements. The following is an example setup:

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