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

Ethernet Tester Needs No LEDs, Only Your Multimeter

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.

Arduino Cable Tracer Helps Diagnose Broken USB Cables

We’ve all found ourselves swimming amongst too many similar-looking USB cables over the years. Some have all the conductors and functionality, some are weird power-only oddballs, and some charge our phones quickly while others don’t. It’s a huge headache and one that [TechKiwiGadgets] hopes to solve with the Arduino Cable Tracer.

The tracer works with USB-A, Mini-USB, Micro-USB, and USB-C cables to determine whether connections are broken or not and also to identify wiring configurations. It’s built around the Arduino Mega 2560, which is ideal for providing a huge amount of GPIO pins that are perfect for such a purpose. Probing results are displayed upon the 2.8″ TFT LCD display that makes it easy to figure out which cables do what.

It’s a tidy build, and one that we could imagine would be very useful for getting a quick go/no-go status on any cables dug out of a junk box somewhere. Just remember to WIDLARIZE any bad cables you find so they never trouble you again. Video after the break.

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Build Your Own LAN Cable Tester

Sure, you can buy a cable tester, but what fun is that? [Ashish] posted a nice looking cable tester that you can build with or without an onboard Arduino. If you don’t use an Arduino, the project uses a 555 chip to test the eight wires in an Ethernet cable. The readout is simple. When testing a conductor, one of 8 LEDs will light. If one doesn’t light, the cable is open. If more than one light up, there is a short. Mixed up pins will cause the LEDs to light out of sequence. You can see the device in the video below.

The 555 device is fine for the design and we were surprised that the project had provisions for using an Arduino as nothing more than a pulse generator. It could replace most of the circuit which is pretty simple. A decade counter converts the pulses into 8 pulses (a wiring change makes it reset on the 9th count). The rest of the circuit is nothing more than LEDs, resistors, and diodes.

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