Supported Simulator

In addition to debug probes, PyAvrOCD also supports the simulation tool simavr by providing a pass-through service. If you use the Arduino IDE 2, then the way to start the simulator is as follows:

  1. Verify/compile your sketch.
  2. Choose Simulator (simavr) as the Programmer in the Tools menu.
  3. Click on the Debugger icon at the top of the window.

If you use the VSCode extension Arduino Maker Workshop, it works the same. In PlatformIO, you can select simavr as a debugging tool in the platformio.ini configuration file.

An alternative way to start simavr is to provide a path argument to the --start option that has as its last part simavr. If you use another IDE other than the ones mentioned above, you can trigger that by putting the file pyavrocd.options into the project folder containing the two lines

--start
/path/to/simavr-executable

Note that the list of chips supported by simavr is much smaller than the one supported by PyAvrOCD. Further, the means of interaction are severely limited. However, the simulator solution may sometimes be the more preferable option.

If you are adventurous, try out a few other things with simavr. It is possible to pass arguments to simavr using the option --xarg or -x. Note that each string must be passed separately as an argument, as in the example below. Use the <option>=<value> notation to pass options such as --add-trace in order to avoid the interpretation of these options as PyAvrOCD options.

For instance, you can trace the changes of a particular memory location, e.g., PORTB on an ATmega328P, where the built-in LED is usually controlled. Add the following lines in the file pyavrocd.options:

--xarg=--add-trace
--xarg='LED=trace@0x0025/0xff'

After terminating the debug session (and waiting some time), a VCD trace will show up in the project folder. This can be visualized, for instance, with gtkwave or pulseview. It is also possible to provide VCD files as input. This is all sketched in a simavr usage note.