Inside a 1980s filter chip that uses switched capacitors

Sometimes it's easier to identify an IC with a microscope. While sorting a box of old ICs, CuriousMarc came across some Harris ICs labeled "F1-10-5", a mysterious part number that didn't show up in any databooks. Since unidentifiable ICs are useless, he gave me one to analyze. Conveniently, it was in a ceramic package, so I could open it up with a quick tap from a chisel. Under the microscope, the chip's most striking feature was a grid of square capacitors. With all those capacitors, I guessed that it was a switched-capacitor filter. The die provided another clue: the part number HF-10. With this information, we...

M5Stack ToughC5 weatherproof ESP32-C5 IoT controller offers dual-band Wi-Fi 6, BLE 5, and Zigbee/Thread

M5Stack has just introduced the ToughC5, a rugged, weatherproof outdoor IoT controller built around the ESP32-C5. The device features a bright 2.0-inch capacitive touch IPS display and RS485 connectivity. The ToughC5 is an upgrade to the ESP32-base3d M5Stack TOUGH introduced in 2021, with the upgraded model featuring a more modern ESP32-C5 MCU with dual-band (2.4/5 GHz) Wi-Fi 6, Bluetooth 5 LE, and an IEEE 802.15.4 radio for Zigbee and Thread. Other changes include faster Octal PSRAM, an upgraded RTC chip with a dedicated coin cell backup battery, a passive buzzer replacing the previous 1W speaker, and a custom power management...

Radxa's Q8B has 2x the performance and expansion of the Pi 5

There was a time I'd look at a board like the Radxa Dragon Q8B (at left, above) and be like, "there's no way I'd spend $209 on an SBC with 8 gigs of RAM". But we're in 2026, and seeing the 8 gig Raspberry Pi 5 going for almost the same amount, I figured I'd give it a shot.

On paper, the Q8B beats the Pi 5 in pretty much every way. A lot of that is thanks to this Snapdragon 8cx Gen 3 chip, which is the same chip I tested on Microsoft's Windows Dev Kit 2023.

Open-source ESP32-C3 DNS ad blocker supports up to over 500,000 domains without PSRAM

Developed by Zed (M-Abozaid), the esp32-c3-adblock is an open-source, Pi-hole-style DNS ad blocker that runs on a $2 ESP32-C3 microcontroller board/module without requiring PSRAM. It blocks ads and tracking domains across devices on a home or small office network by filtering DNS requests. Instead of storing domain strings in RAM, the project stores them as sorted 40-bit FNV-1a hashes in flash memory and uses binary search to check DNS requests. When a UDP DNS query comes in, the C++ firmware extracts the domain, hashes it (including parent suffixes), and performs a binary search against the flash hash table. If the...

Open Fest 2026 is November 7 and 8 in Interpred WTC Sofia

Open Fest, the biggest open-source event in Bulgaria, is approaching! This year, it will take place on November 7–8 at Interpred WTC. As always, Olimex will host its traditional soldering workshop for anyone interested in learning how to solder. Participation is free! You’ll receive a soldering kit, assemble it yourself, and take it home with […]

К истории радиоламп. Ранние приборы с внешними электродами

Как и любая другая эволюция, развитие приёмно-усилительных электровакуумных приборов (ЭВП) имело и тупиковые ветви, образцы, из которых сейчас выглядят престранно и чужеродно. Одна из таких ветвей — внешние электроды. Взглянем же на некоторые примеры этих технических курьёзов, попытаемся понять причину их появления и исчезновения, полюбуемся своеобразной «тёплой ламповой» эстетикой, присутствующей даже в таких нежизнеспособных уродцах.

Зачем в нём пять NE555? Оживляем переговорное устройство из кабины лифта

Приветствую всех!

Помимо уже знакомых нам блоков, обеспечивающих связь с диспетчером, в лифтах применяются и более экзотические аппараты. Ко мне в руки попал как раз один из таких — переговорный блок от лифта конца девяностых.

Зачем он вообще нужен, с кем через него связывались и как он работает? Как оказалось, штука эта куда интереснее, чем я ожидал...

Intel Twin Lake-Based Helix 320 Industrial Gateway with Quad 2.5GbE

OnLogic’s newest industrial edge gateway, the Helix 320, features a fanless design powered by Intel N-Series Twin Lake processors. The compact system includes four 2.5GbE ports, two configurable serial ports, M.2 expansion, and support for up to three displays. OnLogic offers the Helix 320 with two Intel N-Series “Twin Lake” processors: N250 – 4-core/4-thread architecture, […]

Sipeed SLogic32U3 – A high-speed 10 Gbps USB 3.2 logic analyzer (Crowdfunding)

Sipeed has just launched what they claim is the world’s first 10 Gbps USB 3.2 logic analyzer. The SLogic32U3 is the successor to the SLogic16U3 3.2 Gbps logic analyzer launched in 2025. The SLogic32U3 USB-C logic analyzer supports up to 32 channels via four mini HDMI connectors, 350 MHz signal bandwidth, up to 1400 MS/s per channel with four channels, or 200 MS/s per channel with 32 channels, and is offered with an optional ADC module. SLogic32U3 specifications: FPGA – Not mentioned (potentially from GOWIN) Input channels – 32 digital channels via 4x mini HDMI ports, each with 8 channels...

Q8botOne – A palm-sized open-source quadruped robot with ESP32-C3, DYNAMIXEL smart actuators (Crowdfunding)

ZeroWire Robotics Q8botOne is an open-source, palm-sized quadruped robot built around an ESP32-C3 MCU and ROBOTIS DYNAMIXEL smart actuators. Designed with a unique wire-free architecture, the robot integrates all components onto a central printed circuit board also used as the structural chassis. The robot is roughly the size of a smartphone and can jog, jump, and carry up to twice its 250-gram weight. The main PCB uses a dedicated 6V/16A step-down converter for motor power and includes a battery management system for two 14500 Li-ion cells. For control, the kit includes a separate ESP32-C3 controller PCB with an Adafruit Mini...