Circuit Diagram Hello internet, I stuck at some point while simulating my circuit. This is a circuit that will measure distance and display it on seven segment displays. Firstly, When I tried to simulate this circuit I'm getting these errors;

[SPICE] Gmin step [0 of 120] failed: GMIN=0.001

[SPICE] Gmin stepping failed.

[SPICE] Source step [0 of 120] failed: source factor = 0.0000

[SPICE] Too many iterations without convergence.

Real Time Simulation failed to start.

When I connect an oscilloscope to the 3rd pin of the 555 (U3), the simulation works, but this time I can't get the result I want. I tried to simulate only 555 circuits in another project and they can produce their outputs correctly. I tried to simulate only HCSR04 but I couldn't see anything on the echo pin. Did I make any mistake while connecting some components? Is there a way to simulate the whole circuit?

  • 1
    \$\begingroup\$ Does the HCSR04 even have a simulation model? \$\endgroup\$
    – Hearth
    Nov 27, 2022 at 18:50
  • \$\begingroup\$ yes, it has simulation model \$\endgroup\$
    – Robottur
    Nov 27, 2022 at 19:05
  • \$\begingroup\$ What does Proteus manual says about how to use HCSR04 in a simulation? \$\endgroup\$
    – Justme
    Nov 27, 2022 at 19:06
  • \$\begingroup\$ I don't know, where should I look for the manual? \$\endgroup\$
    – Robottur
    Nov 27, 2022 at 19:17

1 Answer 1


I solved problem about the HCSR04. When I change battery with power pin and remove the resistor at the seven segments upper pins, it is solved but I can't simulate in real time. I'm getting CPU error.


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