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Help Understanding Simulation Errors

Natustell

Feb 6, 2023
2
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Feb 6, 2023
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I'm new to KiCad and I'm using it for work. I built my circuit with SPICE models (or so I think) and I am being bombarded with a litany of errors the moment the simulation starts. I have used LTSpice before, but it was much "plug and play". I followed a beginner tutorial to help me create my circuit.



Note: No compatibility mode selected!

warning, can't find model '<no_net>' from line

ra? <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> 0 <no_net> /v_cs_n /v_cs_p_s /v_cs_p_s /v_vs_c /v_vs_c <no_net> <no_net> <no_net> unconnected-_m_sw-pad2_ <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> 40

Circuit: KiCad schematic

Error on line 11 or its substitute:

ra? <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> 0 <no_net> /v_cs_n /v_cs_p_s /v_cs_p_s /v_vs_c /v_vs_c <no_net> <no_net> <no_net> unconnected-_m_sw-pad2_ <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> <no_net> 40

unknown parameter (<no_net>)

Background thread stopped with timeout = 0

Error: circuit not parsed.



I researched this as much as possible, and I have no idea what anything here means. "Error on line 11 or its substitute:" is especially confusing because I never wrote or saw and code directly.



I wish I could share the sketch, but I am not the owner. I can give abstracted descriptions of it as necessary and that's it. I had to change the name of the sketch to "KiCad schematic" after I read the error message so you can imagine how little information I can give.



Somethings I will say initially:



It's purpose is to send a current pulse to a device many times and measure the resistance across it over time.



It contains a microcontroller that is simulated as just a resistor.



It contains a spice MNMOS which is toggled by the microcontroller in reality and is modeled as a pulsed voltage source in the simulation



It contains a voltage source to model a power supply that must be shielded from varying load by an RC filter.
 

crutschow

May 7, 2021
839
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May 7, 2021
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839
I built my circuit with SPICE models (or so I think)
How did you build those models or where did they come from?
Spice requires very particular syntax for all Spice models.

But I'm not familiar with KiCad simulations so can't help you beyond that.
 

Natustell

Feb 6, 2023
2
Joined
Feb 6, 2023
Messages
2
How did you build those models or where did they come from?
Spice requires very particular syntax for all Spice models.

But I'm not familiar with KiCad simulations so can't help you beyond that.
I don't think "build models" accurately describes what I did. I just placed things then edited the spice model. I did the following:

Add Symbol > search for "spice" > select relevant component > place it and set Reference and Value

...or, if there is no pre-made spice component, Add Symbol > select relevant component > place it and set Reference and Value > Spice Model > choose Passive, Model, or Source > fill out settings accordingly

Most components are passive resistors and capacitors. The microntroller has a symbol with all it's actual terminals, but the spice model is a resistor. The transistor, which is switched by the microcontroller in reality, has an MNMOS symbol and a spice model that is a voltage source set to output a pulse. This seemed easier than trying to get a switching signal from the microcontroller and modeling the transistor as an actual transistor.
 

bidrohini

Feb 1, 2023
165
Joined
Feb 1, 2023
Messages
165
I think you'll get more accurate answers if you post this to KiCad forum.
 
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