www.logiccircuit.org

I just discovered logiccircuit.org on Friday (2/1/19) and by the end of the weekend I completed a rather large design, starting from scratch. My design consisted of 4, 3 digit (BCD) 7-segment displays and a bunch of logic to update them at 30FPS. Each of the 4, 3 digit displays received a trigger from a shared (muxed input) A/D converter that indicated that the new 10 bit value was ready for display (I used the constant to test this). Without going into details, this project used about 20 of logiccircuit "logic chips" or a bunch of chips that I made that closely resembled their actual, purchasable parts. I almost filled the entire available workspace.

I have to say that this is one of the most intuitive, easy to learn, easy to use, design tools that I have come across in a long time. The instructions are well written, to the point, plain language with good examples. That cut down on the "learning curve". The tool made my job a lot easier and probably eliminated a re-spin or two when I go to build this. It also gave me a way to demonstrate the functionality before I build anything.

That said, I have a few questions about a features that I, either was not using right or couldn't find in the help or forum. If these not already dealt with, please take them as comments:

Cut/paste and copy/paste.
It seems to paste on or near where the copy was made, not where you place the cursor. That makes connections wherever a pin touches a net. My workaround was to select/move the entire workspace, then paste (at the spot where the copy came from, now blank), then put things back and add the copied section. That worked until my design got real big and filled the whole workspace. Am I missing something on how/where to paste my cut/copy/paste?

Speaking of workspace, can the size be changed? How large of a design can this tool handle?

Junctions (connection dots). They don't always appear. I found it necessary to pick the next, nearby grid on the net, highlight the split net on one side or the other, then drag the connection to the joining net.

I used the component rotate (L/R) which takes care of many situations but I couldn't find a way to mirror horizontally. That made wiring to a splitter a bit difficult. Is there any way to mirror?

Search within the forum. I had trouble finding some basic items, like how to mirror components or many of the items in this post. Is there a better way to phrase questions?

Zoom. I was having difficulties with zoom throughout my design. I have poor eyesight and need to zoom a lot. Can you zoom on highlighted component or center screen? Also the zoom slider location is difficult to use because I use the "hide" property on the bottom tray. Can the slider be moved? Are there zoom function keys?

Components are always on top (can't see through component). This was a problem because there can be an underlying net from input to output. Some form of transparency or automatic net elimination would help (LTspice is a good example) - this makes drawing nets easier and corrects user errors when drawing them. Maybe even the ability to put components (all or individually) on top or bottom would help. Is there any way to deal with this?

The scope graticule doesn't line up with any signal – I found it hard to figure out what is happening in what order. A marker would help or a "sync" on a particular waveform would be helpful. Also a change time-base would be great. Are any of these features available somehow?

Thanks.

Hi, welcome.

To answer your questions:

• Paste places components where they where copied, unless an existing component lies there. You can move the the highlighted design without affecting other parts of the design by holding shift. This can be annoying, but is way better than moving the whole design.

• The workspace is a fixed size, but the program can handle an impressive amount of components (100000+components, though at a leisurely pace) when using sub circuits. Also, using more subcircuits/wires to make the design look better, does not impact performance as the design is flattened before simulation.

• Connections only appear on ends of wire segments, you can split a wire by highlighting it the alt-clicking on the desired location(You might know this, but it is the easiest way). Connections can only be made on the grid.

• There is no way of mirroring a design, but splitters have left/right variants. Eugene, please implement

• There is not a lot of activity on this forum, chances are if you cant find it, nobody have asked it.

• The slider is the only way to zoom, and it scales around (0,0) in the design, not the center of the viewscreen. I have been annoyed at this myself as ctrl+mousewheel should zoom and shift+mousewheel should scroll horizontally. Ideally it should zoom around the center of the viewscreen, but this is a minor annoyance. The slider cannot be moved, unless you modify the source and compile it yourself.

• You can highlight a net (a wire and all connected wires) by holding shit and clicking on it. This will show through components. Drawing wires under components is for the most part not a good choice, at least not in logiccircuit. If there is an input on the lest side and an output on the right side, it might be better to route the wire around the circuit instead of under. How one would add automatic net removal, i don't know

• The scope seems underdeveloped and not that usefull.

Some of this might have changed in the latest version, but i'm using a older version because of a glitch in the handling of tri-state wires in one of the newer releases.

That being the case, anyone can feel free to add to this of correct my mistakes.
Also if this doesn't answer all of you questions, feel free to clarify/ask again.

Hi,
To add to sir Kamba.
You can see report on the complexity of your project in the menu Tools\Project Report.
I suggest you read help pages at: https://logiccircuit.org/help.html
I encourage you to keep each circuit as simple as possible. This will not only make it easier to understand but also eliminate a lot or errors and let you reuse your components more widely.
I will see how to implement zooming with mouse wheel in the future releases.
You can also use some Edit menu commands to find all kind of wiring problems. For example, you can select all wires and see if there any one hidden under the symbols.
You can see multiple signals form probes on oscilloscope. But its resolution is only lined up to the system clock. If you need to see all the changes on any probe you can double click it and see the exact history on that probe. You can add mark to better see the changes.
Hope this helps,
Eugene

Thanks for the informative reply - I didn't see the L/R connector
I just spent a bit of time with more comments and questions one of which was about uploading a file I just made to learn the LED matrix and the ROM. I dragged it to this post and when I dropped it an unformatted xml file appeared and blew away my post. What did I do wrong?
Part of it was to share the file with other beginners. Now I like the wires under the components and the way they can be routed directly to the I/O. Looks ugly but saves time troubleshooting and learning. On the splitter, I now see the Left/Right - duh! That's great and was my main issue. Need to slow down and read.

forgot the file - goes with my previous post