Tag: dw-link

Debugging 2.0

September 14, 2023 / nebel / 0 Comments

The featured image of this blog post is based on vector graphics by captainvector at 123RF.

What keeps people from using a debugger? Well, it is mostly that one has initial costs in terms of setting up the debugging environment and of learning how to use the debugging tool. Hopefully, the next iteration of my hardware debugging tool dw-link, which is able to debug classic ATtinys and ATmegaX8s, will somewhat ease that burden, in particular, because you can buy the accompanying hardware now at Tindie.

Fixing Problems … Using Super-Global Variables

February 3, 2022 / nebel / 0 Comments

Another xkcd comic that hits the spot. Except, with my new hardware debugger, this is the past 😎. Recently, I debugged one of my electronic geocaching gadgets and was positively surprised how easy it was to figure out ones own mistakes and to come up with the right fix.

A debugWIRE Hardware Debugger for Less Than €10

January 13, 2022 / nebel / 0 Comments

The featured image of this post is based on a picture by Florian-if published on Wikipedia under CC-BY-SA-3.0

Is it possible to build a hardware debugger for debugWIRE for less than €10? As it turns out, it is. You just have to make a few compromises and also do a bit of soldering and gluing.

dw-probe: The Hardware for the Hardware Debugger

January 4, 2022 / nebel / 0 Comments

dw-link can turn your Arduino board into a hardware debugger, and dw-probe connects it to any target board.

That’s One Small Step for a Man, One Giant Leap for a Debugger: On Single-Stepping and Interrupts

January 2, 2022 / nebel / 0 Comments

The featured image of this post is by WikiImages on Pixabay

You want to make a single step in your program, but the debugger takes you to some unknown area of the program. This was, in fact, my first experience when I tried out Microchip’s MPLAB X IDE debugger on the innocent blinking sketch. Is this a bug or a feature?

dw-link: A New Hardware Debugger for ATtinys and Small ATmegas

December 31, 2021 / nebel / 2 Comments

As mentioned in an earlier blog post this year, hardware debuggers are the premier class of embedded debugging tools. However, until today, there were only very few relatively expensive tools around supporting the debugWIRE interface that is used by the classic ATtinys and a few ATmega MCUs.

The good news is that now you can turn an Arduino UNO, Nano, or Pro Mini into a debugWIRE hardware debugger that communicates with avr-gdb, the AVR version of the GNU project debugger.

Surprise, Surprise!

December 29, 2021 / nebel / 2 Comments

The featured image of this post is by Albert Guillaume – Gils Blas, 24 décembre 1895, Public Domain, Link

When you develop a tool for a protocol that is undocumented, it is not surprising that you will encounter situations you will not have be anticipated. This was exactly what I experienced developing the hardware debugger dw-link, which connects debugWIRE MCUs to the GDB debugger. Although a substantial part of the debugWIRE protocol has been reverse-engineered, I encountered plenty of surprising situations: Split personality MCUs, stuck-at-one bits in program counters, secret I/O addresses, half-legal opcodes, and more.

Debugging a Debugger With Itself

December 27, 2021 / nebel / 0 Comments

The featured image of this post is is a comic from xkcd.com.

The above xkcd comic, which is titled Debugger, alludes to the concern that when you try to apply a particular method to itself, you might not get what you asked for. Turing’s Halting problem is a very famous example of this, i.e., you cannot algorithmically decide whether an algorithm terminates on an input. So, does that issue apply to debuggers as well? In particular, I asked myself whether it makes sense to debug the hardware debugger I am developing with itself.