Programming robots with GLL
Gate Logic Language: a circuit language plus live simulator with Modbus sync. What I actually use to drive Factory I/O robot cells.
Most of my “serious” hours lately are not spent on game prototypes. They’re spent on GLL — Gate Logic Language — and the simulator around it, written in C++ with SFML.
You write circuits in a small text language, drop the file on the simulator, and watch signals propagate live. Green is high, red is low. Space to run, period to step, click inputs to poke the world.
Why it exists
I wanted something between a textbook logic trainer and a tiny soft-PLC: readable circuit source, immediate feedback, and a way to talk to the outside world.
That last part is Modbus TCP. The GLL simulator can sync internal signals with a remote Modbus server — which, in practice, means I can drive Factory I/O scenes: arms, conveyors, pick-and-place cells, the whole industrial toybox.
So yes: this is the tool I reach for when I’m programming robot logic. Not a mockup. Not a charter. A .gll file, a running sim, and hardware (or a simulated plant) on the other end of Modbus.
What’s in the box
- GLL language + documentation
- Real-time evaluation and single-step
- Input toggles and button widgets
- Windows releases on GitHub (build yourself elsewhere — SFML 3, CMake, libmodbus)
It’s still hobbyist software. I’m not selling it as certified PLC tooling. But if you need a honest line on the shelf for “things I actually use,” this is the one.