Today, I’d like to highlight a tool that brings your hacking skills to a whole new level, and does that without breaking the bank – in fact, given just how much debugging time you can save, how many fun pursuits you can unlock, and the numerous features you can add, this might be one of the cheapest tools you will get. Whether it’s debugging weird problems, optimizing your code, probing around a gadget you’re reverse-engineering, or maybe trying to understand someone’s open-source library, you are likely missing out a lot if you don’t have a logic analyzer on hand!
It’s heartbreaking to me that some hackers still don’t know the value that a logic analyzer brings. Over and over again, tactical application of a logic analyzer has helped me see an entirely different perspective on something I was hacking on, and that’s just the thing I’d like to demonstrate today.
A logic analyzer has a number of digital inputs, and it continuously reads the state of these digital inputs, sending them to your computer or showing them on a screen – it’s like a logic-level-only oscilloscope. If you have an I2C bus with one MCU controlling a sensor, connect a logic analyzer to the clock and data pins, wire up the ground, launch the logic analyzer software on your computer, and see what’s actually happening.
For instance, have you ever noticed the ID_SC and ID_SD pins on the Raspberry Pi GPIO connector? Are you wondering what they’re for? Don’t you want to check what actually happens on these pins? Let’s do that right now! Continue reading “Logic Analyzers: Tapping Into Raspberry Pi Secrets”