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8 Bit Division with Remainder circuit from my calculator project!
| I made up a schematic of the division unit for my recent calculator project, with some adjustments. I switched out a few chips with ones from the same family, but I tried to keep it as close to the original as I could. The original also only took 7 bits for the divisor as it only took up to 99 as an input due to the interface of the calculator. Definitely could be optimized. This is my first time translating a circuit of this size to a schematic, so it might be... messy. Hopefully I didn't miss anything; I checked it over a few times. A few adjustments might be required. "Start" must remain low until dividend and divisor are inputted. This signal must remain high until the XOR signal, from carryout and OR, is high, which then tells the circuit that the result is negative and to stop subtracting the divisor. I have a video of the division unit from when i was still testing it as well. I plan and am working on creating a whole schematic of my calculator without any changes, but do beware that my demonstration of the unit isn't 1:1 as it's from early on in testing, same with the second photo. https://youtu.be/GKElo5Bfb7c [link] [comments] |
Made a skeleton circuit with an 8-bit shift register
| First time trying something like this! [link] [comments] |
Weekly discussion, complaint, and rant thread
Open to anything, including discussions, complaints, and rants.
Sub rules do not apply, so don't bother reporting incivility, off-topic, or spam.
Reddit-wide rules do apply.
To see the newest posts, sort the comments by "new" (instead of "best" or "top").
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High school student who made a custom PCB for a 3d LiDAR scanner
| I'm a high school student who has an interest in point clouds and spatial data, so I made my own LiDAR scanner! This was my first time making a PCB, and the scanner runs on an esp32 & TMC2209 stepper drivers. You can see my Github with the KiCAD project files here. [link] [comments] |
Конкурс "Інтелект молоді. Раціональне природокористування та новітні енергоефективні технології"
♻️КПІшники — серед переможців VI Всеукраїнського конкурсу з міжнародною участю «Інтелект молоді. Раціональне природокористування та новітні енергоефективні технології»
У КПІ відкрили меморіальну дошку Герою України Андрію Гуцалу
☑️ У корпусі №19 КПІ ім. Ігоря Сікорського відкрили меморіальну дошку Андрію Дмитровичу Гуцалу — випускнику Київської політехніки, регбісту клубу «Політехнік», майору Державної прикордонної служби України, Герою України.
My Crystodyne amplifier
| As one of like 3 people who absolutely loves cat whiskers when I stumbled upon a paper from the 1920s known as “the Crystodyne principle” I got real excited, then I realized I don’t own zincite and ya I know the paper itself says you can use galena and fools gold but I’ve over used fools gold and if I’m gonna buy galena why not spend that money on zincite, but then I had a genius idea “what if I made the crystal!” So then I got to work (spent like 5minutes finding out how zincite forms) and discovered it’s just the mineral equivalent to zinc oxide so I heat treated some zinc WITH A MASK NO ONE WANTS ZINC PLATED LUNGS, and to my surprise it worked 2nd try. The hardest part had to be actually making the circuit because “the Crystodyne principle” doesn’t tell you how to make an amplifier only that you can so like any responsible science fella I just started shoving crap together based on half complete knowledge till it worked and then when I got it to work I needed to figure out how to A. Remove unnecessary components B. Increase volume C. Decrease static. And this is the circuit I came up with. To test it I put the earpiece in my ear under a pair of headphones and tapped the mic against an auto transformer. I also managed to use it to amplify an electric kazoo. [link] [comments] |
Surface mount and microwaves

Upside-down mounting can deliver inductance upsides for surface mount passives and other components.
Please visualize the structure of a surface mount resistor as shown in the following Figure 1:

Figure 1 Surface mount resistor constituents include this writeup’s showcase electrical contacts.
Normally this part would be installed on a circuit board with the outer coating visible for inspection and with the substrate adjacent to the circuit board’s surface. However, if the circuit board’s goodies are operating at microwave frequencies, this might not be the best idea.
There is an alternative, however, as shown in Figure 2:

Figure 2 A surface mount resistor in its normal-service mounting orientation (a) may be re-positioned for optimal microwave-service operation (b).
If the surface mount resistor is installed on the circuit board “upside down”, the inductances presented by the electrical contacts will be much reduced versus that of the usual mounting. At microwave frequencies this can be significant, especially if the resistance is 50Ω in a matched impedance application.
John Dunn is an electronics consultant and a graduate of The Polytechnic Institute of Brooklyn (BSEE) and of New York University (MSEE).
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- Thin-film chip resistors operate in harsh environments
- The y-, z-, h-, and s-parameter alphabet soup
The post Surface mount and microwaves appeared first on EDN.
🧐 Конкурс учнівських проєктів “Автоматизація навколо нас”
🏁Є ідея, як автоматизувати щось у школі, вдома, місті та повсякденному житті? Запрошуємо учнів 10–11 класів прийняти участь у конкурсі учнівських проєктів “Автоматизація навколо нас”.
Photon Design adds silicon modulator design capability to its HAROLD laser simulation tool
Guerrilla RF launches flagship linear PA module for 4.4–5.2GHz band
Volta Metals awarded up to $500,000 from Ontario’s Critical Minerals Innovation Fund
Bring-up and testing of systems with CXL Type 3 memory expanders

This series of articles is written for system bring-up engineers, post-silicon validation engineers, platform firmware developers, kernel and driver integrators, and test architects who are—or will soon be—working with Compute Express Link (CXL) Type 3 memory expanders in real hardware. If your job involves taking a server from first power-on to production-ready memory expansion, reconciling what firmware advertises with what the operating system actually consumes, or explaining why a workload is “slow on CXL” when link training looks clean, this material is aimed at you.
This mini-series assumes you already understand PCIe fundamentals and have a working mental model of CXL device types and topologies. It does not re-teach CXL from first principles; instead, it focuses on the practical cross-layer problems that dominate bring-up and validation; discovery versus usability, non-uniform memory access (NUMA) placement versus link health, and policy configuration versus silicon defects.
How will this mini-series help
CXL Type 3 memory is deceptively familiar. From software’s perspective, it looks like RAM; from a validation perspective, it behaves like a small distributed system spanning expander ASIC firmware, host BIOS, ACPI tables, kernel drivers, and user-space tooling. Failures at one layer often masquerade as symptoms at another—a missing NUMA node that is really an HDM validity problem, or a “slow” benchmark that is really default allocator placement on far memory.
This mini-series gives you a structured playbook to:
- Set performance and correctness expectations using the latency–capacity pyramid and NUMA topology, so you know when a workload should tolerate CXL-attached memory and when it will not.
- Verify platform prerequisites across CPU, BIOS, kernel, and device firmware before spending days on the wrong debug path.
- Use the standard Linux tooling chain—cxl, ndctl, daxctl, numactl, lspci—to distinguish “device not seen,” “device seen but not consumable,” and “device online but misconfigured”.
- Walk the boot timeline from slot power and DRAM training through DVSEC discovery, decode programming, CDAT delivery, and driver bind, with a validation mindset at each gate.
- Interpret transport-layer and CXL-specific configuration-space indicators, run targeted memory traffic, and separate link issues from NUMA policy and memory-mode configuration faults.
The goal is to reduce time spent debugging the wrong layer and to give you checklists and command-level examples you can adapt into lab gates, CI smoke tests, and field triage runbooks.
What each part covers
Part 1: Why CXL Type 3 memory matters, and what your platform must provide
Part 1 establishes the system context. It explains why AI and data-intensive workloads are driving interest in memory expanders, how CXL Type 3 devices differ from local DIMMs even when they appear as ordinary RAM, and where expander memory sits in the latency–capacity pyramid relative to socket-local DRAM and storage.
It then walks through platform prerequisites—CPU enablement, BIOS/firmware, kernel support, device firmware, and RAS—and explains why features such as CXL IDE or tiered memory only work when every layer is aligned. The part closes with the NUMA story on Linux: how cxl_pci binds Type 3 endpoints, why expander memory often appears as a separate or “far” NUMA node, and why many CXL issues show up as placement and bandwidth imbalance rather than hard functional failures.
Part 2: Tooling and boot path from power-on to usable memory
Part 2 is the operational core. It introduces the user-space utilities that make CXL state visible beyond dmesg—cxl/libcxl for fabric topology, ndctl and daxctl for region and DAX/system-RAM modes, numactl for placement experiments, and lspci/hwloc for bus- and topology-level sanity checks.
It then traces the end-to-end boot sequence: power and clocks, on-device DRAM training and SPD discovery, gating of host-managed device memory (HDM) until mem_info_valid is asserted, PCIe/CXL link up and DVSEC-based discovery, decode programming and mem_enable, CDAT transport over DOE and mailbox health, ACPI handoff via CEDT/SRAT/HMAT, and final OS driver binding. Each stage is framed as an implied test with characteristic failure signatures, so you can map symptoms to the most likely layer quickly.
Part 3: Test, debug, and validation of CXL memory expanders
Part 3 turns theory into hands-on practice. It covers integration modes—system RAM versus device DAX—and when boot parameters such as efi=nosoftreserve or daxctl reconfigure-device apply.
It shows how to confirm expander memory as a distinct NUMA node with numactl, decode key lspci fields (link width/speed, CXL DVSEC capabilities, HDM range Valid/Active bits, cxl_pci binding), and drive traffic with numactl placement plus tools such as Intel MLC, stressapptest, and memtester. The series concludes with a cross-layer validation mindset, suggested future work for multi-device and pooled topologies, and references for deeper reading.
Read all three parts if you are new to CXL Type 3 bring-up; jump to Part 2 or Part 3 if you already have a booting system and need tooling or debug guidance.
Ameet Sanghavi works in post-silicon validation for PCIe and CXL at Nvidia with a focus on interface bring-up and validation on shipping products. He has worked on PCIe since 2005 (from PCIe 1.1 onward) and on CXL since 2020 (from CXL 1.1 onward).
Related Content
- Stripped Down CXL Scales Memory Wall
- CXL Efforts Focus on Memory Expansion
- CXL Adds Port Bundling to Quench AI Thirst
- CXL: The key to memory capacity in next-gen data centers
- From GPUs to Memory Pools: Why AI Needs Compute Express Link (CXL)
The post Bring-up and testing of systems with CXL Type 3 memory expanders appeared first on EDN.
Projet electronics, arroseur automatic de plante
| Je travail sur un projet d'arrosage de plante autonome souhaite moi bonne chance 😂😉 [link] [comments] |
My first ever USB-UART PCB, Hand soldered by me. (Type-C 16P, 0603 & SOP-8 components)
| All thanks to one single person who believed in me & pushed me to do it! [link] [comments] |
Nimy and Curtin University awarded funding for gallium processing research in Western Australia
Veeco’s new LUMINA+ MOCVD system qualified by Ennostar
The Kembak 1 was the 1st personal computer, 1971. It used TTL ICs, not a microprocessor.
| submitted by /u/1Davide [link] [comments] |
Георгій Васильєв: діяльність на перетині науки, освіти та державної політики
Призначення іменних стипендій Верховної Ради України для молодих учених – докторів наук – це матеріальна підтримка наукової діяльності молодих дослідників та створення можливостей і стимулів для реалізації наукових експериментів в Україні у межах пріоритетних напрямів розвитку науки і техніки. У 2025 році серед 47 молодих дослідників-стипендіатів, що отримують персональну щомісячну підтримку від держави, було і двоє молодих науковців КПІ.



