Analog simulation

Velxio doesn’t only propagate digital highs and lows. The analog parts of your circuit — resistors, diodes, transistors, power sources — are solved by a SPICE-class engine that runs coupled with the digital simulation, the way mixed-mode simulators on the desktop do it.

The SPICE badge

The yellow badge above the circuit reports the analog network:

• nets — how many electrical nodes the engine is solving.
• solve time — what the last analysis cost.

When a board pin drives an analog network (say, a GPIO through a resistor into an LED), pin edges from the firmware feed the analog solve, and the resulting voltages and currents drive what you see — LED brightness included.

What’s modeled

• Passives — resistors, potentiometers, and the wiring itself.
• Diodes and LEDs — real exponential I/V behavior with per-color forward voltages.
• Transistors — bipolar transistors (NPN/PNP) with proper junction models; motor-driver and relay circuits behave realistically.
• Logic families — discrete logic ICs (74xx and friends) modeled with family-accurate levels.
• Power — supplies, regulators, batteries in the power category.

The engine keeps improving release by release; if an exotic analog corner behaves unexpectedly, simplify the circuit or ask in the community.

The circuit verifier

Before a run, Velxio checks the circuit for configurations that would damage real parts — the classic being an LED across a supply without a series resistor. In electrical mode the verifier blocks the run and points at the problem; fix the wiring and run again. It’s a feature: the simulator teaches the habit that saves real LEDs.