A digital logic simulator.
Zigital aims to do primitive digital logic simulation via vanilla JavaScript with HTML5 canvas. React is used as a UI to user settings and pallette selections. The postgreSQL db and backend api is implemented via Flask/SQLAlchemy.
Zigital uses a finite state machine implementation to model the circuits in real time. Wire paths are computed via A* and connections are instantiated when inputs and outputs are connected. An evaluation function fires whenever power states are modified and the FSM is transitioned to the next state.
It is best practice to place down components and then move on to wire, click inputs to outputs to instantiate a component in the finite state machine. By clicking power sources (low/high voltage), state will be updated and the results can be interpreted via connections to bulbs. Left click to cancel path currently being drawn. Note that delete will remove all components at the moment, I am looking to fix this shortly. Projects can be saved and loaded but currently I have not yet implemented abstraction of components.
- [OPEN] Abstraction of circuits to be used as custom components; this will be done via compilation of truth tables by permuting over all possible inputs. From this it would be relatively straightforward to return a custom logic function for the desired component via closure.
- [CLOSED] Heuristic to A* can and should be modified to limit number of turns; this will improved the gnarling of paths which is a bit of an issue for massive circuits. -- SOLVED, (however my heuristic can still be improved. It may be worth while to look at some of the source code of Kicad as my method by use of testing local cross product of visited and future displacements is not very predictive)
- [OPEN] Canvas overflow handling needs to be implemented, surprisingly unpacking projects doesn't lead to crash on small screen sizes. Should size of canvas be set dynamically or fixed? I'm leaning towards fixed. Some CSS trickery is likely needed. Perhaps scrolling is simplest.
- [OPEN] On load, tool should default to 'click' to make pressing buttons less confusing.
- [CLOSED] Currently deletion of wires is done in one foul swoop, a proximity deletion to a wire needs to be implemented post haste to make quick modification of wires less taxing. -- SOLVED: lame solution
- [CLOSED] Snap highlighting is missing on bulb and power components, this is a trivial fix. -- SOLVED
- [CLOSED] Snap highlighting on gate imputs is slightly dubious, this will need to be rectified in order to facilitate a clean instantiation of connection objects. -- SOLVED
- [CLOSED] Dead links are currently left on the page as a development goal reminder, these will be removed before true deployment. -- SOLVED
- [CLOSED] Serialization of nested JSON objects in the database prove to be a non-trivial task. This is essential for users to be able to save component abstractions and projects. Some more consideration needs to be made as to how this can be accomplished with SQLAlchemy and Alembic. -- SOLVED
- [CLOSED] In the near future A* will be implemented as an alternative to manually routing wires, I have actually already established the code base for this in a prior project (see my maze solving app) but I need to do some more thinking on how to adapt the code cleanly. -- SOLVED
- [OPEN] The next step up from simple combinational logic would be to implement time-dependence in the form of a simple clock.
https://github.com/NLKNguyen/papercolor-theme
http://openbookproject.net/courses/python4fun/logic.html
https://medium.com/@pdx.lucasm/canvas-with-react-js-32e133c05258
https://github.com/johnwinans https://github.com/johnwinans/rvalp/releases https://www.youtube.com/watch?v=em1zDi6q06o
https://amercader.net/blog/beware-of-json-fields-in-sqlalchemy/