====== Using Arbitrary SPICE Engines in KiCad 5 ======

Simulation support in KiCad 5 has been significantly reworked to make it a better simulation platform. However, you might have a lot of SPICE projects that you created in KiCad 4, and reworking them to fit the way things work in KiCad 5 might be more work than you want to undertake. Also, you might be running KiCad on a Debian system, which (as of this writing) [[http://kicad-pcb.org/download/debian/#_build_from_source| doesn't have]] the new simulation support.

The UI bits for the OldWays((Open the //Generate netlist// dialog, click the //Spice// tab and then the //Run Simulator// button)) are still there in KiCad 5, but they no longer work the same way --- at least not on my Debian sid system. In particular, when KiCad generates ''*cir'' files, it no longer prepends ''-PSPICE''/''-GNUCAP'' nor appends ''+PSPICE''/''+GNUCAP'' text blocks found on the schematic to the file. But it does add a ''.title'' directive to the file that my simulator doesn't understand and chokes on.

So, I hacked together a bash script that makes it relatively easy to convert KiCad 4 simulations to something that works in KiCad 5. I'm dumping the source code here for now but may move it to Git[lab|hub] soon.

<file bash simulate.sh>
#!/bin/bash
 
# (C) 2018 Mithat Konar https://mithatkonar.com
 
# A scheme to use arbitrary SPICE simulators in Kicad 5.
#
# Usage:
# * Put all the stuff to be prepended (e.g., -PSPICE stuff) in pre.cir.
# * Put all the stuff to be appended (e.g., +PSPICE stuff) in post.cir.
# * In this script:
#       * Set CIRCUITNAME to point to the .cir file KiCad 5 generates.
#       * Set SPICE_ENGINE to your desired SPICE engine. (Hack the line
#         where it's invoked to add any needed command line parameters.)
# * In the KiCad Netlist dialog's Spice tab, set the simulator to this
#   file using an absolute path.
# * In the KiCad Netlist dialog's Spice tab, Run Simulator.
 
# ----- config ---------------------------------------------------------
# The name of the cir file to simulate with (w/o extension):
CIRCUITNAME=opa-x5-spice
 
# The command for the SPICE engine you want to use:
SPICE_ENGINE="xterm -e ngspice"
# ----------------------------------------------------------------------
 
### constants
CIRCUITFILE=${CIRCUITNAME}.cir
CIRCUITFILE_CLEANED=${CIRCUITNAME}-cleaned.cir
GENERATED_CIR=${CIRCUITNAME}-complete.cir
 
### go!
# set the script's directory as the working directory
cd $( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
 
# remove all lines starting with .title from CIRCUITFILE
sed '/^.title/d' $CIRCUITFILE > $CIRCUITFILE_CLEANED
 
# concatenate the final file
cat pre.cir > $GENERATED_CIR
cat $CIRCUITFILE_CLEANED >> $GENERATED_CIR
cat post.cir >> $GENERATED_CIR
 
# run it
$SPICE_ENGINE $GENERATED_CIR
 
# cleanup
#~ rm $GENERATED_CIR
rm $CIRCUITFILE_CLEANED

</file>