This post is somewhere between a guide and a collection of notes, aimed at debugging programs for AVR microcontrollers (like the ones in most Arduinos) “on target”. We’ll be using an AVR Dragon connected to the target micro via the normal 6-pin programming header, with a Mac or Linux PC as the host.
Although this is a bit more advanced than most of our other projects, it’s really quite approachable and is a very powerful technique for fixing AVR software problems.
From a high level; we’ll use a debugging program on a Mac (or Linux, Windows, etc) “host” computer, which communicates with a Dragon “In Circuit Emulator” (ICE) via USB to debug a buggy program running on the “target” AVR, which is presumably running in some circuit we’re interested in. Small variations might apply for Windows hosts, using JTAG instead of DebugWIRE, other debugger tools (Atmel JTAGICE mkII for example), etc.
Continue reading “Debugging AVRs (without Atmel Studio)”
This evening, I finally got around to unwrapping the Arduino clone that came with my DSpace membership. Starting a project for the board couldn’t be easier, using the nice Arduino IDE from https://www.arduino.cc, but I ran into a little snag when it was time to upload the program onto the board. It turns out that these clone Arduinos use a newish low-cost USB to serial converter chip called a CH340G, rather than the FTDI brand chips used in the genuine Arduino boards. The CH340G that isn’t supported by MacOS by default, and I use MacOS, so the board didn’t show up in the Arduino application’s list of serial ports…
Fortunately, other folks have run into the same problem and have written up some nice blog posts on how to solve exactly this issue!
We had a smaller turn out this time (around a dozen), thanks to school holidays and the Easter break. But everyone there got actively involved and asked a lot of great questions. Many thanks to Anne (who helped set up) and Paul (who typed for me) who helped me get through the night with a broken wrist.
The rest of the talk was learn-by-example and learn-by-doing. We built a web page that provided a simple to-do list webapp.
The code is listed below in the resources. Note that to view the code in your browser for these examples (or any webpage), right click on the page and select “View Page Source”. Or you can just save the page and open it in your favourite text editor.
As usual, there was a lot covered in this talk. And some of the code in the printed handouts (the new stuff in step 4) wasn’t covered, but leads on from what I did cover.
Resources from this talk:
The rest of the talk was learn-by-example and learn-by-doing. I walked everyone through using Mozilla’s Add-on Builder – a webapp that lets you easily code and test Firefox add-ons using the new Add-ons SDK.
We built two add-ons:
- Wikipedia Button – An extremely simple add-on that adds a button to the bar at the bottom of your browser, with the Wikipedia logo. Clicking it will open Wikipedia in a new tab.
- Translate Selection – A less-simple add-on that adds a “Translate Selection” item to your context menu (right-click menu). When you select some text, right click, and select “Translate Selection”, the text you selected will be translated into English (using Google’s translation service).
Resources from this talk: