KiCAD

149 Articles

Create Your RTL Simulations With KiCAD

February 6, 2023 by 4 Comments

[Bob Alexander] is in the process of designing a homebrew discrete TTL CPU, and wanted a way to enter schematics for digital simulations via a Verilog RTL flow. Since KiCAD is pretty good at handling hierarchical schematics, why not use that? [Bob] created a KiCAD plugin, KiCadVerilog allowing one to instantiate and wire up the circuits under consideration, and then throw the resulting Verilog file at your logic simulator of choice.

KiCadVerilog doesn’t do all the hard work though, as it only provides the structure and the wiring of the circuit. The actual guts of each TTL instance needs to be provided, and a reference to it is manually added to the schematic object fields. That’s a one-time deal, as you can re-use the component library once generated. Since TTL logic has been around for a little while, locating a suitable Verilog library for this is easy. Here’s ice-chips-verilog by [TimRudy] on GitHub for starters. It’s intended as a collection for Icestudio (which is also worth a look). Still, the Verilog code for many TTL series devices is presented ready for the taking, complete with individual test benches in case you need them.

Check out the project GitHub page for the module source code, and some more documentation about the design process.

We’ve seen many RTL hacks over the years, here’s an interesting way to generate a PCB layout with discrete logic, direct from the RTL.

Building A Fake Printer To Grab Screenshots Off The Parallel Port

February 3, 2023 by 36 Comments

[Tom Verbeure] recently found himself lamenting the need to take screen grabs from an Advantest R3273 spectrum analyzer with a phone camera, as the older gear requires you to either grab tables of data over an expensive GPIB interface card, or print them to paper. Then he realized, why not make a simple printer port add-on that looks like a printer, but sends the data over USB as a serial stream?

On the hardware side, the custom PCB (KiCAD project) is based on the Raspberry Pi Pico. Obvious form factor issues aside ([Tom] did revise the PCB to make it smaller) this is a shrewd move, as this is not a critical-path gadget so using the Pico as a USB-to-thing solution is a cost-effective way to get something working with minimal risk. One interesting design point was the use of the 74LVC161284 special function bus interface that handles the 5 V tolerance that the RP2040 lacks, whilst making the project compliant with IEEE-1284 — useful for the fussier instruments.

Using the service manual of the Sharp AP-PK11 copier/printer as a reference, [Tom] again, shows how to correctly use the chip, minimizing the design effort and scope for error. The complete project, with preliminary firmware and everything needed to build this thing, can be found on the project GitHub page. [Tom] does add a warning however that this project is still being worked on so adopters might wish to bear that in mind.

If you don’t own such fancy bench instrumentation, but grabbing screenshots from devices that don’t normally support it, is more your thing, then how about a tool to grab Game Boy screenshots?

Showing KiCanvas board viewer component inside a browser window, with a board being displayed and toggleable layers

KiCanvas Helps Teach And Share KiCad Projects In Browsers

January 31, 2023 by 27 Comments

KiCad is undeniably the hacker favourite when it comes to PCB design, and we’ve built a large amount of infrastructure around it – plugins, integrations, exporters, viewers, and much more. Now, [Stargirl Flowers] is working on what we could call a web viewer for KiCad files – though calling the KiCanvas project a “KiCad viewer” would be an understatement, given everything it aims to let you do. It will help you do exciting things like copy-pasting circuits between KiCad and browser windows, embed circuits into your blog and show component properties/part numbers interactively, and of course, it will work as a standalone online viewer for KiCad files!

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KiCad 2022 Year End Recap

KiCad 2022 End-of-Year Recap And 7.0 Preview

December 31, 2022 by 22 Comments

[Chris Gammell] moderated the KiCad 2022 End-of-Year Recap with several KiCad developers and librarians. They reviewed what’s been bubbling up in the nightly KiCad 6 builds, what we can expect from KiCad 7, and even answered some questions from the user community. Over the course of 2022, the KiCad project has grown both its development team and library team. The project even has a preliminary support commitment from the CERN Drawing Office!

Improvements to the KiCad Schematic Editor include smart wire dragging that simplifies moving components around within schematic diagrams. Components selected in the schematic now remain selected while switching to the PCB Editor. Internal documentation of schematics has advanced with support for fonts, embedded graphics, and the inclusion of hypertext links to datasheets and other reference materials. New features for PDF generation offer interactive files and links between sheets.

A new search panel within the KiCad PCB Editor supports finding components by footprint, net, or text search. A property panel allows common properties to be edited across multiple selected items. While a full-blown auto-router remains outside of the scope for KiCad, “push and shove” routing is faster and easier. An “attempt to finish” feature routes a quick connection for the currently selected trace, and “pack and move” positions all selected footprints into proximity to simplify placing them as neighbors within the board layout.

The KiCad PCB Editor also adds support for the use of fonts and inverted “knockout text” which even works on copper zones. Bitmap graphics can be imported and scaled beneath layout work as reference illustrations. Private footprint layers can be used to place extra documentation within footprints. The design rule checker (DRC) now can catch more layout issues, especially those that may impact manufacturability.

These are just a sampling of the impressive improvements we can expect with KiCad 7.0. There are also additions to circuit simulation and modeling features, a new command line interface for script-based automation, ARM64 support for KiCad running on Apple silicon, and a huge number of additions to the default library including symbols, footprints, and 3D Viewer models.

The KiCad team suggests several ways to support the project. There are always needs for additional developers and librarians. Financial contributions can be made at kicad.org. As users, we can run the nightly builds, try to break them, and give feedback in the form of detailed bug reports. Community testing will help make KiCad 7.0 as solid as possible. The project team is also seeking open hardware projects to include with KiCad 7.0 as demos.  For example, the StickHub project was included with KiCad 6.0 as a demo.

The official release of KiCad 7.0 is currently scheduled for January 31, 2023. While we wait, let’s flashback to our January 2022 presentation of what features made it into the KiCad 6.0 release.

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Alpakka: A Creative Commons Game Controller

December 22, 2022 by 21 Comments

Input Labs’ mission is to produce open-source Creative Commons hardware and software for creating gaming controllers that can be adapted to anyone. Alpakka is their current take on a generic controller, looking similar to a modern Xbox or PlayStation controller but with quite a few differences. The 3D printed casing has a low-poly count, angular feel to it, but if you don’t like that you can tweak that in blender to just how you want it. Alpakka emulates a standard USB-attached keyboard, mouse, and Xinput gamepad in parallel so should just work out of the box for both Linux and Windows PC platforms. The firmware includes some built-in game profiles, which can be selected on the controller.

No special parts here, just 3D prints, a PCB and some nuts and bolts

The dual D-pads, augmented with an analog stick, is not an unusual arrangement, but what is a bit special is the inventive dual-gyro sensor arrangement –which when used in conjunction with a touch-sensitive pad — emulates a mouse input. Rest your thumb on the right-hand directional pad and the mouse moves, or else it stays fixed, kind of like lifting a mouse off the pad to re-center it.

The wired-only controller is based around a Raspberry Pi Pico, which has plenty of resources for this type of application giving a fast 250 Hz update rate. But to handle no fewer than nineteen button inputs, as well as a scroll wheel, directional switch, and that analog stick, the Pico doesn’t have enough I/O, needing a pair of NXP PCAL6416A I2C IO expanders to deal with it.

The PCB design is done with KiCAD, using a simple 3D printed stand to hold the PCB flat and the through-hole components in place while soldering. Other than a few QFN packages which might be a problem for some people, there is nothing tricky about hand-soldering this design.

We’ve been seeing custom game controllers as long as we’ve been hacking, here’s an interesting take on the mouse-integration theme. If you’re comfortable rolling the hardware side of things, but the firmware is a sticking point, then perhaps look no further than this neat RP2040 firmware project.

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MikroLeo, A 4-Bit Retro Learning Platform

November 27, 2022 by 22 Comments

MikroLeo is a discrete TTL logic-based microcomputer intended for educational purposes created by [Edson Junior Acordi], an Electronics Professor at the Brazilian Federal Institute of Paraná, Brazil. The 4-bit CPU has a Harvard RISC architecture built entirely from 74HCT series logic mounted on a two-sided PCB using only through-hole parts. With 2K words of instruction RAM and 2K words of addressable RAM, the CPU has a similar resource level to comparable machines of old, giving students a feel for how to work within tight constraints.

Simulation of the circuit is possible with digital, with the dedicated PCB designed with KiCAD, so there should be enough there to get cracking with it. Four 4-bit IO ports make interfacing easy, with dedicated INput and OUTput instructions for the purpose. An assembler, compiler, and emulator are all being worked on (as far as we can tell) so keep an eye out for that, if this project is of interest to you.

We like computers a bit around these parts, the “hackier” and weirder the better. Even just in the 4-bit retro space, we’ve seen so many, from those built around ancient ALU chips to those built from discrete transistors and diodes, but you don’t need to go down that road, an emulation platform can scratch that retro itch, without the same level of pain.

Scripting Coils For PCB Motors

October 25, 2022 by 12 Comments

PCB inductors are a subject that has appeared here at Hackaday many times, perhaps most notably in the electromagnetic exploits of [Carl Bugeja]. But there is still much to be learned in the creation of the inductors themselves, and [atomic14] has recently been investigating their automatic creation through scripting.

A simple spiral trace is easy enough to create, but when for example creating a circular array of coils for an electric motor there’s a need for more complex shapes. Drawing a trapezoidal spiral is a surprisingly difficult task for a script, and we’re treated to a variety of algorithms in the path to achieving a usable design.

Having perfected the algorithm, how to bring it into KiCAD?  The PCB CAD package has its own Python environment built-in, but it’s not the most flexible in which to develop. The solution is to write a simple JSON interpreter in KiCAD, and leave the spiral generation to an external script that passes a JSON. This also leaves the possibility of using the same code in other PCB packages.

You can watch the whole video below the break. Meanwhile for more PCB electromagnetics, watch [Carl Bugeja]’s 2019 Supercon interview.

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