Say you are tinkering with a good system driven by a CPU that uses Serial Wire Debug (SWD), but doesn’t mark the testpoints. Discovering SWD on a board — how tricky could it be? With [Aaron Christophel]’s system, you can locate the SWD interface on a PCB inside a handful of minutes’ time. All you need is two needles, a regarded-to-be-floor relationship, an SWD dongle of some form, and a pc with an audio output. What is very best — you could easily transfer the gist of this system to other programming interface styles!
The concept is uncomplicated: you wire the ground up, connect the needles to SWDIO and SWCLK, launch [Aaron]’s Python script, then start poking close to all the unnamed check points. The script operates JLink program to probe for SWD products hooked up to the probes — if an SWD interface is not uncovered, it beeps idly, but as soon as the gadget is detected, your computer will start off beeping at you in a lively fashion. In this way, you don’t have to re-scan gadgets manually, solder to any check points except the GND just one, or try out and maintain equally probes on take a look at points with just one hand – the scanning approach alone is fingers-absolutely free.
Dependent on how numerous details your board has and irrespective of whether you test to improve the course of action by probing details closest to the SWD pins on the CPU, you may well strike the jackpot quickly, or you could have to poke around for a moment-two. That mentioned, [Aaron]’s strategy looks to be the most effective you can do when remaining somewhat added-components-no cost, and if you want to make it a tinge far more everlasting, clothespins are there for you.
In scenario you really don’t thoughts extra hardware – could we interest you in some 3D printed needle probe desks? There is a broad wide range of people, whether you’d like some tentacle-like types, or types that make your desk seem like like an acupuncture desk. Or, say, would you like a a lot more automated system of finding all types of debug interfaces? Then JTAGulator may well be what you’re on the lookout for.