Eight RS232 Ports, One Ethernet Port

March 16, 2022 by Jenny List 57 Comments

When it comes to impromptu enclosures, [Paul Wallace] is a man after our own hearts, for his serial-to-Ethernet converters allowing him to control older test equipment were housed in takeaway curry containers. Once the test equipment pile had grown it became obvious that a pile of curry containers was a bit unwieldy, even if the curry had been enjoyable, so he set about creating an all-in-one multiway serial to Ethernet box.

Reminiscent of the serial terminal access controllers that were found in dumb terminal sites back in the day, it’s a box with eight DB-9 connectors for serial ports and a single RJ45 Ethernet port. Inside is a Teensy 4.1 which packs a PHY and eight hardware serial ports, and a pile of MAX232 level converter modules. These have a small modification to wire in the CTS and RTS lines, and the whole is clothed in a custom 3D printed case.

The result is a very neat, almost commercial standard box that should save him quite a bit of space. Not everyone has eight devices to drive, so if you have just one how about using an ESP8266?

Receiver board of the Ethernet tester, with only probing pins, and no resistors populated

Ethernet Tester Needs No LEDs, Only Your Multimeter

February 28, 2022 by Arya Voronova 27 Comments

Ethernet cable testers are dime a dozen, but none of them are as elegant and multimeter-friendly as this tester from our Hackaday.io regular, [Bharbour]. An Ethernet cable has 8 wires, and the 9 volts of easily available batteries come awfully close to that – which is why the board has a voltage divider! On the ‘sender’ end, you just plug this board onto the connector, powered by a 9 volt battery. On the “receiver” end, you take your multimeter out and measure the testpoints – TP7 should be at seven volts, TP3 at three volts, and so on.

As a result, you can easily check any of the individual wires, as opposed to many testers which only test pair-by-pair. This also helps you detect crossover and miswired cables – while firmly keeping you in the realm of real-life pin numbers! This tester is well thought-out when it comes to being easily reproducible – the PCB files are available in the “Files” section, and since the “receiver” and “sender” PCBs are identical, you only need to do a single “three PCBs” order from OSHPark in order to build your own!

Bharbour has a rich library of projects, and we encourage you to check them out! If you ever want to get yourself up to speed on Ethernet basics, we’ve talked about its entire history – and we’ve even explained PoE! After some intensive learning time, perhaps you can try your hand at crimping the shortest Ethernet cable ever.

Hacking An Extra SATA Port Into A Thin Client

February 25, 2022 by Lewin Day 24 Comments

Thin clients were once thought by some to be the future of computing. These relatively low-power machines would rely on large server farms to handle the bulk of their processing and storage, serving only as a convenient local way for users to get access to the network. They never quite caught on, but [Jan Weber] found an old example and set about repurposing it as a NAS.

The Fujitsu Futro S900 was built up to 2013, and only had one SATA port from the factory. [Jan] wanted to add another as this would make the device more useful as a network attached storage server.

The motherboard design was intended primarily for industrial control or digital signage applications, and thus has plenty of interfaces onboard. [Jan]’s first target was some unpopulated footprints for SATA ports onboard, but after soldering on a connector, it was found that the BIOS wouldn’t recognise the extra ports anyway.

However, after reflashing the BIOS with one from an alternate model, the port worked! The system also seemed to then imagine it was connected to many additional LAN interfaces, but other than that glitch, the hack is functional. Now, with a pair of 2 TB SSDs inside, the S900 is a great low-power NAS device that can store [Jan]’s files.

It’s a tidy hack, and one that will likely appeal to those who prefer to run their own hardware rather than relying on the cloud. If you’re working on your own innovative NAS project, be sure to let us know!

Tiny Ethernet Cable Arms Race Spawns From Reddit Discussion

February 16, 2022 by Lewin Day 58 Comments

If you’ve had any dealings with Cat 5 and Cat 6 cable, and let’s be honest, who hasn’t, you’ve probably wrestled with lengths anywhere from 1 meter to 25 meters if you’re hooking up a long haul. Network admins will be familiar with the 0.1 m variety for neat hookups in server cabinets. However, a Reddit community has recently taken things further.

It all started on r/ubiquiti, where user [aayo-gorkhali] posted a custom-built cable just over 2 inches long. The intention was to allow a Ubiquiti U6-IW access point to be placed on a wall. The tiny cable was used to hook up to the keystone jack that formerly lived in that position, as an alternative to re-terminating the wall jack into a regular RJ45 connector.

Naturally this led to an arms race, with [darkw1sh] posting a shorter example with two RJ-45 connectors mounted back to back with the bare minimum of cable crimped into the housings. [Josh_Your_IT_Guy] went out the belt sander to one-up that effort, measuring just over an inch in length.

[rickyh7] took things further, posting a “cable” just a half-inch long (~13 mm). In reality, it consists of just the pinned section of two RJ-45 connectors mounted back to back, wired together in the normal way. While electrically it should work, and it passes a cable tester check, it would be virtually impossible to actually plug it into two devices at once due to its tiny length.

We want to see this go to the logical end point, though. This would naturally involve hacking away the plastic casings off a pair of laptops and soldering their motherboards together at the traces leading to the Ethernet jack. Then your “cable” is merely the width of the solder joint itself.

Alternatively, you could spend your afternoon learning about other nifty hacks with Ethernet cables that have more real-world applications!

Teardown: Alcatel Telic 1 Minitel Terminal

February 16, 2022 by Jenny List 34 Comments

For British teenagers in the 1980s, the delights of 8-bit computers such as the Sinclair Spectrum, Commodore 64, or BBC Micro were firmly restricted to the offline arena. We would read about the BBS scene on the other side of the Atlantic, but without cheap local calls and with a modem costing a small fortune, the chances of us ever experiencing one was zero. When we took the British school rite of passage of a trip to France though, we were astounded to see that every French person was not merely online, but that they were doing so with a neat little all-in-one terminal. We’d just been introduced to the French Minitel system, and in that minute shared a glimpse of the future.

Un Réseau Trés Français

The Minitel terminal is a small CRT monitor with a fold-down alphanumeric keyboard. — My Alcatel Minitel terminal

In the 1970s and 1980s, so-called videotext systems, terminal-based phoneline access to information services on central computers, were seen as an obvious next step for telephone network operators with an interest in profitable new products. In most countries this resulted in services such as the UK’s Prestel, a subscription service relying on costly hardware, but France Télécom instead pursued the bold path of making the terminals free to subscribers with free access to phone listings and yellow pages, but a business model based on pay-to-use premium services.

Thus, through the 1980s all French households had a Minitel terminal beside the phone, and the service became a runaway success. Ever since seeing Minitel terminals as a tourist I’d been fascinated by the service, so here in the 2020s when a friend was visiting their family in France I asked whether he could pick up an old Minitel terminal for me. Thus I found myself parting with around $25 and being rewarded with a slightly battered Minitel cardboard box containing one of the familiar brown Alcatel terminals. I certainly wasn’t expecting one in its original packaging. Continue reading “Teardown: Alcatel Telic 1 Minitel Terminal” →

That Clock On The Wall Is Actually A Network Ping Display

February 9, 2022 by Dan Maloney 15 Comments

We’ve all been online from home a bit more than usual lately, in ways that often stretch the limits of what our ISP can muster. You know the signs — audio that drops out, video sessions that make you look like [Max Headroom], and during the off-hours, getting owned in CS:GO by pretty much everyone. All the bandwidth in the world won’t make up for high latency, and knowing where you stand on that score is the point of this ping-tracking clock.

This eye-catching lag-o-meter is courtesy of [Charl], who started the build with a clock from IKEA. Stripped of pretty much everything but the bezel, he added a coaxial clock motor and a driver board, along with a custom-printed faceplate with logarithmic scale. The motors are driven by an ESP32, which uses internet control message protocol (ICMP) to ping a trusted server via WiFi, calculates the proper angles for the hands, and drives the motors to show you the bad news. There’s also an e-paper display in the face, showing current server and WiFi settings.

We really like how this clock looks, and if it wasn’t for the fact that the numbers it displays would often be too depressing to bear, we’d build one in a snap. If facing the painful truth isn’t your style, there are other neat ICMP tricks that you can try instead.

First Hacks: The Brand New Nokia 5G Gateway Router

December 27, 2021 by Jenny List 29 Comments

Aside from being the focus of a series of bizarre conspiracy theories, 5G cellular networks offer the promise of ultra-fast Internet access anywhere within their range. To that end there are a new breed of devices designed to provide home broadband using 5G as a backhaul. It’s one of these, a Nokia Fastmile, that [Eddie Zhang] received, and he’s found it to be an interesting teardown and investigation. Spoiler: it runs Android and has exploitable bugs.

A privilege escalation bug in the web administration tool led to gaining the ability to export and modify configuration files, but sadly though a telnet prompt can be opened it’s not much use without the password. Uncovering some blocked-off ports on the base of the unit revealed a USB-C port, which was found to connect to an Android device. Via ADB a shell could be opened on Android, but on further investigation it was found that the Fastmile is not a single device but two separate ones. Inside is a PCB with an Android 5G phone to handle the connection, and another with a completely separate home router.

With access to the Android side and a login prompt on the router side that was as far as he was prepared to go without risking bricking his Fastmile. It only remained to do a teardown, which reveals the separate PCBs with their own heatsinks, and an impressive antenna array. Perhaps these devices will in time become as ubiquitous as old routers, and we’ll see them fully laid bare.

It’s a shame that we’ve had to write more about the conspiracy theories surrounding 5G than real 5G devices, but maybe we’ll see more teardowns like this one to make up for it.