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melastmohican

80 karma · joined April 19, 2026

Hi, I'm Mariusz (melastmohican). I'm a Software Engineer based in Bellevue, Washington. By day, I build highly scalable backend microservices, cloud infrastructure, and distributed systems (Java/Spring/AWS). By night, I'm a passionate hardware hobbyist. I tinker heavily with Embedded Systems, pushing cheap clone boards to their limits using modern Embedded Rust (STM32, ESP32). Fighting memory coherency, undocumented datasheets, and writing bare-metal drivers is my idea of fun. When I'm not staring at code, I'm an avid photographer with a massive portfolio covering everything from the Getty Center to the Alaskan wilderness. I sell my work through stock sites like Shutterstock. GitHub: https://github.com/melastmohican Photography: https://www.shutterstock.com/g/melastmohican
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melastmohican··on A Matter Wi-Fi Light Bulb in Rust on the Raspberry Pi Pico 2 W
I was playing with the official Espressif Rust Board, which is ESP32C3, but I didn't try Matter on it. It would be on the same boat as Pico W because it only supports Matter over Wifi. https://github.com/melastmohican/esp-rust-board-discovery Now I would try something like ESP32C6 with Thread support: https://github.com/melastmohican/adafruit-feather-esp32c6-em...
melastmohican··on A Matter Wi-Fi Light Bulb in Rust on the Raspberry Pi Pico 2 W
I was happy to make it work at all :-) There is a guy on the internet who measures the power consumption of many mcus and concludes the nrf52840 is the best: https://www.youtube.com/watch?v=KE7bOYCYETM
melastmohican··on A Matter Wi-Fi Light Bulb in Rust on the Raspberry Pi Pico 2 W
Actually, you can make it work with Arduino Nano Matter. It boils down to vendor support. If they support Arduino like Silicon Labs or Espressif, then it is available for hobbyists.
melastmohican··on A Matter Wi-Fi Light Bulb in Rust on the Raspberry Pi Pico 2 W
The initial approach was to run BLE and Wi-Fi simultaneously. Provisioning sometimes worked. It seems like there was some interference. Then switched to run BLE with Wi-FI off. When I got Wi-Fi credentials, switched BLE off, and turned Wi-Fi on. It still had some issues. Turned out when slowed down SPI bus, it started working. Only tested with Home Assistant and have to fork and patch rs-matter-embassy
melastmohican··on A Matter Wi-Fi Light Bulb in Rust on the Raspberry Pi Pico 2 W
Hi HN,

I’ve been experimenting with the new Raspberry Pi Pico 2 W (RP2350) and wanted to see how difficult it would be to build a fully compliant Matter smart device from scratch using Rust.

I put together a complete "Blinky" example using the rs-matter stack and the embassy async framework. It uses BLE for the initial commissioning phase and Wi-Fi for network connectivity. Once flashed, you can provision it directly into Apple Home, Google Home, or Home Assistant using your smartphone—no cloud accounts required. It exposes a standard Matter On/Off cluster that toggles a physical LED wired to the GPIO pins.

A few interesting technical notes from the build:

Bare Metal: It runs entirely no_std on bare metal using embassy-rp. Radio Coexistence: Getting the CYW43439 wireless chip to handle concurrent BLE (for commissioning) and Wi-Fi (for Matter IP traffic) on the RP2350 took some tweaking. We actually had to dial back the PIO SPI clock divider specifically because the RP2350's faster 150MHz core clock was causing bus corruption when the radio was saturated! Async Rust: The repo includes the full async CoEx (coexistence) runner setup to safely multiplex the radio between the Bluetooth and Wi-Fi stacks concurrently. If you’ve been wanting to build local-only smart home devices but felt intimidated by the massive official C++ Matter SDK, doing it in Rust is actually becoming incredibly approachable.

Would love to hear if anyone else is building custom smart home gear in Rust.

melastmohican··on The Cost of Cheap Clone Boards: Streaming Video on an STM32H750
Hi HN, I recently picked up the WeAct Studio MiniSTM32H750VBTX. On paper, it's a dream for $10: a 480MHz Cortex-M7, built-in ST7735 TFT, and an OV2640 camera interface. In reality, the documentation is a black hole. I wanted to build a real-time video pipeline using modern Embedded Rust. Because I couldn't find any good existing Rust examples for this specific board, I ended up writing my own suite of 20+ examples ranging from basic GPIO to a playable 60FPS Chrome Dino clone. The blog post linked above details the absolute carnage of getting the video pipeline working—fighting Cortex-M7 cache coherency, fixing double-bit ECC RAM faults because the DMA was hitting uninitialized memory, and diagnosing "colorful sand" byte-order mismatches. The full repository with all the working Rust examples is here: https://github.com/melastmohican/stm32h750vb-examples I'd love to hear if anyone else has fought with these cheap, undocumented STM32 clone boards, or if you have tips on better managing the MPU/SRAM4 memory coherency in Rust!