Software

A Networking Mystery

Over the past two days, I found myself conducting a complete forensic analysis of my network. Something unexpected had changed the IP address of my main host’s bridge0 interface. Given that a critical React Server Components vulnerability had been released (GHSA-fv66-9v8q-g76r), and I had recently deployed several new Docker containers—some with access to the host Docker socket (I know, not ideal)—I immediately suspected a compromise.

The situation felt serious. By sheer luck, changing the bridge interface address cut all network access to my homelab, which at least contained the potential damage. I examined every Docker image on the system, but found nothing suspicious.

The Hardware Testing Challenge

When developing hardware, the challenging phase begins after the prototype is designed and PCBs are manufactured. The easy part—conceptualization and board design—is behind you. What follows is infinitely harder:

• Making boards electrically alive and verifying proper operation with electrical jigs and test equipment
• Programming and validating firmware behavior
• Testing the complete system’s functionality under real-world conditions
• Building the infrastructure—both hardware and software—to support comprehensive testing

For devices communicating via NMEA protocols, this challenge is compounded by the complexity of marine electronics standards and the difficulty of simulating real maritime data streams.

Why ESP32C5?

I’m researching hardware options for an upcoming project, and the ESP32 family appears to be the best fit for our current requirements.

For years, a major drawback of Espressif chips was limited support to 2.4GHz WiFi only. Why does this matter? Having a 2.4GHz device on a WiFi network degrades performance for all other devices, forcing users to set up separate WiFi routers just for 2.4GHz devices. Additionally, the initial configuration proved frustrating—when your phone is on 5GHz, the ESP Touch protocol doesn’t work reliably.

Using Compiler and ELF to Avoid Ifdef and Flags Hell for Selecting Runtime Features

I was digging into redis source recently and i came to realise some lesser know features
of gcc/clang needs some more publicity, so i will write about them here.

The problem: You want to get best of the CPU/Hardware/Features but usual way to do this
is either build for specific hardware or use runtime checks both have drawbacks.
First on a new hardware you need a new build and results in

Vevor 7 in 1 Wifi to Windy and HomeAssistant

For a long time i wanted to install a weather station but since
i have to put it on a roof which is easily accessded by outside
people i needed something on the budget side.

So during a recent Ali promotion i got one - Vevor 7 In 1 WiFi
model.

You need the WiFi version, there non-WiFi version which you can work
with too but you need to have RTL SDR dongles and recode radio data send
from the outdoor unit to the sensor. This post is about the WiFi only.

A Teaser of What to expect from our upcoming WiFi connected 2 channel relay board.

Web UI of the relay board

Main control screen and part of the configuration

Main control screen

Part of the configuration

Schedule editor

Hi,

A simple i2c driver for the Microchip’s TCN75A thermometer – supports up to 8 thermometers. Driver works in one shot mode which is suitable for battery powered operations. The chip is with quite good specs for its price.

Code at github esp_i2c_tcn75a .

Usage:  checkout user/user_main.c for example usage.

Enjoy!

73

 

After a lots of lots of wasted hours  debugging an I2C driver it came out that the noise from the connected cheep USB2TTL converter is way too much. Would have lost months without the help of the new DS1054z scope i’ve got.

So i came up with this – a simple UDP debugging.

Simple socket to send udp messages.

dbg

Call dbg_udp_start(0) and you are ready to go. If you prefer not to flood your LAN with debug messages broadcasts then instead of 0 provide your workstation IP address.

In case you’ve missed it! Kicad is going to get some really nice features!

While working on a current project i’ve faced an issue with code reuse. Espressif sdk allows only one interrupt handler for all GPIOs. That’s fine for monolithic code but since we like modular code a dispatcher comes handy.

The little inconvenience i’ve had was like this. I wanted to use the drivers/key.c code but it does use the data argument , so i’ve had to modify it to use a global variable. So i can call it from my own interrupt handler. And that is ugly.