Schematic of the Pi Pico wireup, showing the various outputs that the firmware will generate on the GPIOs

A Scope Test Tool You Can Build With Just A Pico

May 31, 2024 by Arya Voronova 24 Comments

Ever wanted to see how well your oscilloscope adheres to its stated capabilities? What if you buy a new scope and need a quick way to test it lest one of its channels its broken, like [Paul Wasserman] had happen to him? Now you only need a Pi Pico and a few extra components to make a scope test board with a large variety of signals it can output, thanks to [Paul]’s Sig Gen Pi Pico firmware.

Despite the name it’s not a signal generator as we know it, as it’s not flexible in the signals it generates. Instead, it creates a dozen signals at more or less the same time — from square waves of various frequencies and duty cycles, to a PWM-driven DAC driving eight different waveforms, to Manchester-encoded data I2C/SPI/UART transfers for all your protocol decoder testing.

Everything is open source under the BSD 3-Clause license, and there’s even two PDFs with documentation and a user manual, not to mention the waveform screenshots for your own reference.

It’s seriously impressive how many features [Paul] has fit into a single firmware. Thanks to his work, whenever you have some test equipment in need of being tested, just grab your Pico and a few passive components.

Screenshot of the Kaby Lake CPU pinout next to the Coffee Lake CPU pinout, showing just how few differences there are

Intel’s Anti-Upgrade Tricks Defeated With Kapton Tape

May 31, 2024 by Arya Voronova 60 Comments

If you own an Intel motherboard with a Z170 or Z270 chipset, you might believe that it only supports CPUs up to Intel’s 7th generation, known as Kaby Lake. Even the CPU socket’s pinout is different in the next generation — we are told, it will fit the same socket, but it won’t boot. So if you want a newer CPU, you’ll have to buy a new motherboard while you’re at it. Or do you?

Turns out, the difference in the socket is just a few pins here and there, and you can make a 8th or 9th generation Coffee Lake CPU work on your Z170/270 board if you apply a few Kapton tape fixes and mod your BIOS, in a process you can find as “Coffee Mod”. You can even preserve compatibility with the 6th/7th generation CPUs after doing this mod, should you ever need to go back to an older chip. Contrasting this to AMD’s high degree of CPU support on even old Ryzen motherboards, it’s as if Intel introduced this incompatibility intentionally.

There’s been a number of posts on various PC forums and YouTube videos, going through the process and showing off the tools used to modify the BIOS. Some mods are exceptionally easy to apply. For example, if you have the Asus Maximus VIII Ranger motherboard, a single jumper wire between two pads next to the EC will enable support without Kapton tape, a mod that likely could be figured out for other similar motherboards as well. There’s a few aspects to keep in mind, like making sure your board’s VRMs are good enough for the new chip, and a little more patching might be needed for hyper-threading, but nothing too involved.

Between money-grab features like this that hamper even the simplest of upgrades and increase e-waste, fun vulnerabilities, and inability to sort out problems like stability power consumption issues, it’s reassuring to see users take back control over their platforms wherever possible, and brings us back to the days of modding Xeon CPUs to fit into 775 sockets.

Don’t get too excited though, as projects like Intel BootGuard are bound to hamper mods like this on newer generations by introducing digital signing for BIOS images, flying under the banner of user security yet again. Alas, it appears way more likely that Intel’s financial security is the culprit.

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A picture of the camera in question, successfully uploading a pic thanks to the fix found

Fixing A Camera’s WiFi Connectivity With Ghidra

May 30, 2024 by Arya Voronova 4 Comments

If your old camera’s WiFi picture upload feature breaks, what do you do? Begrudgingly get a new one? Well, if you’re like [Ge0rg], you break out Ghidra and find the culprit. He’s been hacking on Samsung’s connected cameras for a fair bit now, and we’ve covered his adventures hacking on Samsung’s Linux-powered camera series throughout the last decade, from getting root on them for fun, to deep dives into the series. Now, it was time to try and fix a problem with one particular camera, Samsung WB850F, which had its picture upload feature break at some point.

[Ge0rg] grabbed a firmware update .zip, and got greeted by a bunch of compile-time debug data as a bonus, making the reverse-engineering journey all that more tempting. After figuring out the update file partition mapping, loading the code into Ghidra, and feeding the debug data into it to get functions to properly parse, he got to the offending segment, and eventually figured out the bug. Turned out, a particularly blunt line of code checking the HTTP server response was confused by s in https, and a simple spoof server running on a device of your choice with a replacement hosts file is enough to have the feature work again, well, paired with a service that spoofs the long-shutdown Samsung’s picture upload server.

Turned out, a bunch more cameras from Samsung had the same check misfire for them, which made this reverse-engineering journey all that more fruitful. Once again, Ghidra skills save the day.

Design Review: USB-C PD Input For Yaesu FRG7700

May 23, 2024 by Arya Voronova 21 Comments

Today is another board from a friend, [treble], who wants to convert a Yaesu FRG7700 radio to USB-C PD power. It’s yet another review that I’ve done privately, and then realized I’ve made more than enough changes to it, to the point that others could learn from this review quite a bit. With our hacker’s consent, I’m now sharing these things with you all, so that we can improve our boards further and further.

This board’s idea is thought-out and executed well – it replaces a bespoke barrel jack assembly, and is mechanically designed to fit the screw holes and the free space inside the chassis. For USB-PD, it uses a CH32V003 coupled with FUSB302 – I definitely did help pick the latter! For mechanical reasons, this board is split into two parts – one has the USB-C port, whereas the other has the MCU and the PD PHY.

In short, this board is a PD trigger. Unlike the usual PD triggers, however, this one is fully configurable, since it has a 32-bit MCU with good software support, plus, the PD PHY is also well known and easily controllable. So, if you want special behavior like charger-power-dependent profile selection for powering a static resistance load, you can implement it easily – or, say, you can do PPS for variable voltage or even lithium ion battery charging! With a bit of extra code, you could even do EPR (28 V = 140 W power) with this board, instantly making it into a pretty advanced PD trigger, beyond the ones available on the market.

Also, the board has some PCB art, and a very handy filter to get some of the USB-C charger noise out. Let’s take a look at all of these!

Current Flow Improvements

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DisplayPort: Hacking And Examples

May 16, 2024 by Arya Voronova 17 Comments

So far, I’ve talked about why DisplayPort is the future, introduced the basics of how to work with it on the hacker level, took apart and tamed the DisplayPort altmode, and recently, went through the eDP (embedded DisplayPort) display technology. This time, I want to give you a project library to reference, so that your hacking goes as smoothly as possible – real-world examples of open-source DisplayPort boards, a few boards I’ve worked on, part numbers, and whatever other information you might need.

Even this wonderful build is not immune from wasting power on unnecessary video conversion

Over the past few years, I’ve noticed that a non-zero amount of cyberdeck builders buy eDP screens with HDMI converter boards on Aliexpress, then connect them to SBCs using USB-C to HDMI adapters, or ignore the onboard eDP port; even this super cool Framework-based cyberdeck has done that! I get that it’s the simplest option, but I do believe that you ought to know how to improve it. The issue is that this double-conversion decreases the battery life significantly by burning two extra ASICs doing video conversion back and forth. Every hour of battery life matters in a cyberdeck, doubly so if it’s based on a low-power device already – you could easily cut your battery life in half if you’re not careful!

With these projects and references in your arsenal, my aim is that DisplayPort becomes way more comfortable for you to work with. Thankfully, there are quite a few projects to reference by now – let’s delve in.

Right out of the gate – are you looking for an SBC with DisplayPort support? The BoardDB website, a database of single-board computers, has a DisplayPort filter – click this link with the filter already enabled and browse through.

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PCB Design Review: HDMI To LVDS Sony Vaio LCD Devboard

May 14, 2024 by Arya Voronova 23 Comments

Today, we revisit another board from [Exentio] – a HDMI/DVI to LVDS transmitter for the Sony Vaio P display. This board is cool to review – it has a high-speed serial interface, a parallel interface, a healthy amount of power distribution that can be tricky to route, and many connectors to look over.

I’ve decided to show this review to you all because it demonstrates a PCB improvement concept we haven’t yet touched upon, that you should absolutely know about when doing board layout. Plus, I get a chance to talk about connector choice considerations!

The board is lovely. It integrates the DPI-LVDS circuit we’ve previously reviewed, but also a HDMI to parallel RGB chip from Texas Instruments, TFP401, a chip appreciated enough that even Adafruit has adapters with it. The fun thing about this chip is that it doesn’t even handle EDID like the usual HDMI to RGB/LVDS chips you get on cheap Aliexpress boards. So, there’s no firmware to take care of – it just receives a HDMI/DVI signal, converts it into parallel RGB, then converts that to LVDS, and off to the display it goes. The downside is that you have to provide your own EDID with an EEPROM, but that isn’t that tricky.

Again, this is a two-layer board, and, again, I like this – fitting tracks to the smallest possible space is a respectable and enjoyable challenge. This board has absolutely done well by this challenge. I do see how this board could be routed in an even better way, however, and it could be way way cleaner as a result. For a start, rotating the chip would improve the odds a whole lot.

The Chip Gets Rotated

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The film scanner [xssfox] found, in the center of a table, with other stuff strewn across the table

Answering All Your ISCSI Scanner Questions

May 12, 2024 by Arya Voronova 17 Comments

iSCSI is a widely used protocol for exposing SCSI devices over a network connection, and some scanners have in the past been equipped with SCSI ports. So, could you have an iSCSI network scanner? [xssfox] details her journey making a Canoscan FS4000US film scanner work over iSCSI, sparked by someone’s overly-confident StackOverflow comment that it couldn’t be done. Nothing in the spec said it couldn’t actually work, however, and after figuring out a tentative architecture, a hardware setup was put together.

No flatbed scanners with SCSI ports could be found on the cheap, so a film scanner had to be procured. After figuring out a few hitches with the loading mechanism and getting a test image locally, it was time to try and build up the software setup, tearing through SCSI compatibility and cabling, driver and PCI pass-through woes, bluescreens, and intermediate software having dropped some of the necessary features by now. Still, [xssfox] eventually exported the scanner as an iSCSI target – and, on the other end of the network, successfully connected to it and completed a scan. The StackOverflow answer was wrong, after all.

It’s fun to see how far old technology can go, and get answers to questions you never knew you had. Whether you’re reminiscing about SCSI days or wondering what the technology about, we’ve talked about it aplenty, from a retrospective to modern-day experiments, repurposing old SCSI hardware for modern SATA ports, a Raspberry Pi implementation, an emulator, and a fair bit more.

We thank [Valentijn Sessink] and [adistuder] for sharing this with us!