LXA IOBus 4DO-3DI-3AI

Not all projects boot from SD cards, sometimes boards are flashed via USB, boot from an eMMC or even from NAND¹. To switch the active boot mode in this case, you usually just have to short-circuit two pins, or press a button. Since this quickly becomes tiring, especially during constant tests, there is now an elegant technical solution:

The LXA IOBus 4DO-3DI-3AI allows to switch small electrical loads and thus e.g. automatically, where otherwise jumpers would have to be set manually, to switch between different boot modes or to trigger resets, which are otherwise performed by pressing a button. In addition, the 4DO' can be used to read supply voltages or collect digital status feedback and feed it back into the test automation.

candleLight

In our blog post The LXA IOBus line of lab automation devices we already reported about the ideas to change our lab-internal communication from USB to CAN. A recurring problem with this: a consumer computer cannot do CAN. In our lab servers we usually solve this problem with PCI-Express CAN cards, but for developer laptops these cards are too clunky.

Instead, we like the open source candleLight project very much. So well, in fact, that we decided to brand it with a Rocket Penguin logo and add it as a product to the store.

RJ45-Matrix

The RJ45-Matrix is another small, but still very fine toy from the LXA-Tools series. The RJ45-Matrix can be used to make connections between all lines of two RJ45 jacks via solder bridges or any 0402 SMD components.

What have we used the RJ45 matrix for so far?

• As a breakout board for RJ45 jacks on 2.54mm pin headers.
• To swap Ethernet pairs between two Ethernet ports.
• To couple two Ethernet devices via 0402 capacitors AC to feed PoE voltages directly.

What other uses could we think of?

• To create loopback connections, e.g. to test very long two-wire links over much shorter eight-wire cables.
• Generating defined cross talk by coupling the different pairs together.
• Inserting e.g. resistive losses into a line.

¹ What kinds of headaches NAND can create as a boot source would be a great topic for another blog post. Until then, perhaps remember: "Avoid if possible!"