Software development is fun when the system works exactly as designed, including both nominal and off-nominal paths. It would be less so if something didn’t work and we had to reconstruct a mental…

In an earlier post, we looked at the stopping mechanism of the Train state machine. In particular, the substate AutoMotorRest stops the train gradually by sending the event MOTOR_RUN_REQ with the target speed…

This is a series of blog posts about asynchronous software design using statecharts. While there are quite a few resources on basic statechart notations and tools, there aren’t really many realistic examples applicable…

We are continuing our journey on this garden model train named Hierarki to explore model-based software design. In this post, we illustrate some cool features of statecharts with GpioIn, a state-based driver for…

In the previous post, we showed how we modeled a GPIO interrupt pin with a hierarchical state machine (HSM) named GpioIn. Its simple design enforces the following properties: With infinite number of waveforms…