WIP

4 files changed, 390 insertions, 81 deletions

diff --git a/coil_parasitics.py b/coil_parasitics.py
index 3ed02dd..d759bd0 100644
--- a/coil_parasitics.py
+++ b/coil_parasitics.py
@@ -115,8 +115,9 @@ def cli():
 
 @cli.command()
 @click.option('-d', '--sim-dir', type=click.Path(dir_okay=True, file_okay=False, path_type=Path))
+@click.option('-o', '--output', type=click.Path(dir_okay=False, writable=True, path_type=Path), help='Capacitance matrix output file')
 @click.argument('mesh_file', type=click.Path(dir_okay=False, path_type=Path))
-def capacitance_matrix(mesh_file, sim_dir):
+def capacitance_matrix(mesh_file, sim_dir, output):
     physical = dict(enumerate_mesh_bodies(mesh_file))
     if sim_dir is not None:
         sim_dir = Path(sim_dir)
@@ -179,6 +180,8 @@ def capacitance_matrix(mesh_file, sim_dir):
                    stderr_log=(tmpdir / 'ElmerSolver_stderr.log'))
         
         capacitance_matrix = np.loadtxt(tmpdir / 'capacitance.txt')
+        np.savetxt(output, capacitance_matrix)
+
 
 @cli.command()
 @click.option('-d', '--sim-dir', type=click.Path(dir_okay=True, file_okay=False, path_type=Path))
@@ -500,34 +503,91 @@ def self_capacitance(mesh_file, sim_dir):
                    stdout_log=solver_stdout,
                    stderr_log=solver_stderr)
         
-        P, R, U_mag = None, None, None
+        C, U_elec = None, None
         solver_error = False
         for l in res.stdout.splitlines():
-            if (m := re.fullmatch(r'StatCurrentSolve:\s*Total Heating Power\s*:\s*([0-9.+-Ee]+)\s*', l)):
-                P = float(m.group(1))
-            elif (m := re.fullmatch(r'StatCurrentSolve:\s*Effective Resistance\s*:\s*([0-9.+-Ee]+)\s*', l)):
-                R = float(m.group(1))
-            elif (m := re.fullmatch(r'MagnetoDynamicsCalcFields:\s*ElectroMagnetic Field Energy\s*:\s*([0-9.+-Ee]+)\s*', l)):
-                U_mag = float(m.group(1))
+            if (m := re.fullmatch(r'StatElecSolve:\s*Tot. Electric Energy\s*:\s*([0-9.+-Ee]+)\s*', l)):
+                U_elec = float(m.group(1))
+            elif (m := re.fullmatch(r'StatElecSolve:\s*Capacitance\s*:\s*([0-9.+-Ee]+)\s*', l)):
+                C = float(m.group(1))
             elif re.fullmatch(r'IterSolve: Linear iteration did not converge to tolerance', l):
                 solver_error = True
 
         if solver_error:
             raise click.ClickException(f'Error: One of the solvers did not converge. See log files for details:\n{solver_stdout.absolute()}\n{solver_stderr.absolute()}')
-        elif P is None or R is None or U_mag is None:
+        elif C is None or U_elec is None:
             raise click.ClickException(f'Error during solver execution. Electrical parameters could not be calculated. See log files for details:\n{solver_stdout.absolute()}\n{solver_stderr.absolute()}')
 
-        V = math.sqrt(P*R)
-        I = math.sqrt(P/R)
-        L = 2*U_mag / (I**2)
-
-        assert math.isclose(V, 1.0, abs_tol=1e-3)
-
-        print(f'Total magnetic field energy: {format_si(U_mag, "J")}')
-        print(f'Reference coil current: {format_si(I, "Ω")}')
-        print(f'Coil resistance calculated by solver: {format_si(R, "Ω")}')
-        print(f'Inductance calucated from field: {format_si(L, "H")}')
+        print(f'Total electric field energy: {format_si(U_elec, "J")}')
+        print(f'Total parasitic capacitance: {format_si(C, "F")}')
 
+@cli.command()
+@click.option('-d', '--sim-dir', type=click.Path(dir_okay=True, file_okay=False, path_type=Path))
+@click.option('--capacitance-matrix-file', type=click.Path(dir_okay=False, exists=True))
+@click.option('--total-inductance', type=float, required=True, help='Total inductance in Henry')
+@click.option('--total-resistance', type=float, required=True, help='Total resistance in Ohm')
+@click.option('--plot-out', type=click.Path(dir_okay=False, writable=True), help='Optional SVG plot output file')
+def resonance(sim_dir, capacitance_matrix_file, total_inductance, total_resistance, plot_out):
+    import PySpice.Unit
+    from PySpice.Spice.Library import SpiceLibrary
+    from PySpice.Spice.Netlist import Circuit
+    from PySpice.Plot.BodeDiagram import bode_diagram
+    import scipy.signal
+    from matplotlib import pyplot as plt
+
+    capacitance_matrix = np.loadtxt(capacitance_matrix_file)
+    num_elements = capacitance_matrix.shape[0]
+
+    circ = Circuit('LC ladder parasitic sim')
+    inputs = 'Vplus', circ.gnd
+    coil_in = 'coil_in'
+
+    Rtest = circ.R('Rtest', inputs[0], coil_in, 50@PySpice.Unit.u_Ohm)
+
+    intermediate_nodes = [f'intermediate{i}' for i in range(num_elements-1)]
+    inductor_nodes = [(a, b) for a, b in zip([coil_in, *intermediate_nodes], [*intermediate_nodes, inputs[1]])]
+    inductor_midpoints = [f'midpoint{i}' for i in range(num_elements)]
+
+    circ.SinusoidalVoltageSource('input', inputs[0], inputs[1], amplitude=1@PySpice.Unit.u_V)
+
+    for i, ((a, b), m) in enumerate(zip(inductor_nodes, inductor_midpoints)):
+        L = total_inductance / num_elements / 2
+        R = total_resistance / num_elements / 2
+        circ.L(f'L{i}A', a, f'R{i}A1', L@PySpice.Unit.u_H)
+        circ.R(f'R{i}A', f'R{i}A1', m, R@PySpice.Unit.u_Ohm)
+        circ.R(f'R{i}B', m, f'R{i}B1', R@PySpice.Unit.u_Ohm)
+        circ.L(f'L{i}B', f'R{i}B1', b, L@PySpice.Unit.u_H)
+
+    for i in range(num_elements):
+        for j in range(i):
+            circ.C(f'C{i}_{j}', inductor_midpoints[i], inductor_midpoints[j], capacitance_matrix[i, j]@PySpice.Unit.u_F)
+
+    sim = circ.simulator(temperature=25, nominal_temperature=25)
+    ana = sim.ac(start_frequency=10@PySpice.Unit.u_kHz, stop_frequency=1000@PySpice.Unit.u_MHz, number_of_points=1000,  variation='dec')
+    figure, axs = plt.subplots(2, figsize=(20, 10), sharex=True)
+
+    freq = ana.frequency
+    gain = 20*np.log10(np.absolute(ana.coil_in))
+
+    peaks, peak_props = scipy.signal.find_peaks(-gain, height=20)
+    for peak in peaks[:3]:
+            print(f'Resonance at {float(freq[peak])/1e6:.3f} MHz')
+    
+    if plot_out:
+        plt.title("Bode Diagram of a Low-Pass RC Filter")
+        bode_diagram(axes=axs,
+                     frequency=freq,
+                     gain=gain,
+                     phase=np.angle(ana.coil_in, deg=False),
+                     linestyle='-',
+        )
+
+        for peak in peaks[:3]:
+            for ax in axs:
+                ax.axvline(float(freq[peak]), color='red', alpha=0.5)
+
+        plt.tight_layout()
+        plt.savefig(plot_out)
 
 
 if __name__ == '__main__':
diff --git a/coil_parasitics_materials.yml b/coil_parasitics_materials.yml
index ecb49b7..d1875d7 100644
--- a/coil_parasitics_materials.yml
+++ b/coil_parasitics_materials.yml
@@ -9,39 +9,21 @@ ro4003c:
   Density: 1790  # 23°C
   Relative Permeability: 1
   Relative Permittivity: 3.55  
+fr4:
+  Density: 1850  # 23°C
+  Relative Permeability: 1
+  Relative Permittivity: 4.4
+  Heat Conductivity: 0.81  # in-plane
 ideal:
   Relative Permittivity: 1 
-copper_inductor:
-  Density: 8960.0  # 20°C
-  Electric Conductivity: 0.0  # necessary for 2D
-  Emissivity: 0.012  # 327°C
-  Heat Capacity: 384.4  # interpolated for 20°C
-  Heat Conductivity: 401.0
-  Relative Permeability: 1
-  Relative Permittivity: 1
 copper:
   Density: 8960.0  # 0°C
-  Electric Conductivity: 32300000  # 200°C
+  Electric Conductivity: 59600000  # 20°C
   Emissivity: 0.012  # 327°C
   Heat Capacity: 415.0  # 200°C
   Heat Conductivity: 401.0  # 0°C
   Relative Permeability: 1
   Relative Permittivity: 1
-graphite_CZ3-R6300:  # crucible
-  Density: 1730.0
-  Electric Conductivity: 58800
-  Emissivity: 0.81  # 205°C
-  Heat Capacity: 1237.0
-  Heat Conductivity: 65  # 20°C
-  Relative Permeability: 1
-  Relative Permittivity: 1
-graphite_FU8957:  # heater
-  Density: 1750.0
-  Emissivity: 0.81  # 250°C
-  Heat Capacity: 1237.0
-  Heat Conductivity: 105  # averaged over different given values
-  Relative Permeability: 1
-  Relative Permittivity: 1
 steel_1.4541:
   Density: 7900.0  # 20°C
   Electric Conductivity: 1370
@@ -50,26 +32,6 @@ steel_1.4541:
   Heat Conductivity: 15.0 # 20°C
   Relative Permeability: 1
   Relative Permittivity: 1
-tin_liquid:
-  Density: 6980.0
-  Electric Conductivity: 2080000
-  Emissivity: 0.064  # set equal to solid
-  Heat Capacity: 252.7
-  Heat Conductivity: 29.0
-  Relative Permeability: 1
-  Relative Permittivity: 1
-  Liquid: 'Logical True'
-tin_solid:
-  Density: 7179.0
-  Electric Conductivity: 4380000
-  Emissivity: 0.064
-  Heat Capacity: 244.0
-  Heat Conductivity: 60.0
-  Relative Permeability: 1
-  Relative Permittivity: 1
-  Solid: 'Logical True'
-  Melting Point: 505
-  Latent Heat: 59600
 water:
   Density: 1000.0
   Heat Capacity: 4182.0
diff --git a/sim_runner.py b/sim_runner.py
new file mode 100644
index 0000000..d615caa
--- /dev/null
+++ b/sim_runner.py
@@ -0,0 +1,282 @@
+#!/usr/bin/env python3
+
+import threading
+import queue
+import itertools
+import pathlib
+import tempfile
+import sys
+import sqlite3
+import time
+import math
+import json
+import subprocess
+
+import tqdm
+import click
+from tabulate import tabulate
+
+
+def mesh_args(db, coil_id, mesh_type, mesh_file, outfile):
+    mesh_type = {'split': '--mesh-split-out', 'normal': '--mesh-out', 'mutual': '--mesh-mutual-out'}[mesh_type]
+    rows = db.execute('SELECT key, value FROM results WHERE coil_id=?', (coil_id,)).fetchall()
+    args = ['python', '-m', 'twisted_coil_gen_twolayer', mesh_type, mesh_file, '--pcb']
+    for k, v in rows:
+        prefix, _, k = k.partition('.')
+        if v != 'False' and prefix == 'gen':
+            args.append('--' + k.replace('_', '-'))
+            if v != 'True':
+                args.append(str(v))
+    args.append(outfile)
+    return args
+
+
+def get_mesh_file(db, mesh_dir, run_id, coil_id, mesh_type):
+    db.execute('CREATE TABLE IF NOT EXISTS meshes(coil_id INTEGER, mesh_type TEXT, error INTEGER, filename TEXT, timestamp TEXT DEFAULT current_timestamp, FOREIGN KEY (coil_id) REFERENCES coils(coil_id))') 
+
+    row = db.execute('SELECT * FROM meshes WHERE coil_id=? AND mesh_type=? ORDER BY timestamp DESC LIMIT 1', (coil_id, mesh_type)).fetchone()
+    if row is not None:
+        mesh_file = mesh_dir / row['filename']
+        if mesh_file.is_file():
+            return mesh_file
+
+    timestamp = time.strftime('%Y-%m-%d_%H-%M-%S')
+    return mesh_dir / f'mesh-{run_id}-{coil_id}-{mesh_type}-{timestamp}.msh'
+
+
+def ensure_mesh(db, mesh_dir, log_dir, run_id, coil_id, mesh_type):
+    mesh_file = get_mesh_file(db, mesh_dir, run_id, coil_id, mesh_type)
+
+    if mesh_file.is_file():
+        return mesh_file
+
+    db.execute('INSERT INTO meshes(coil_id, mesh_type, error, filename) VALUES (?, ?, 0, ?)', (coil_id, mesh_type, mesh_file.name))
+    db.commit()
+
+    mesh_file.parent.mkdir(exist_ok=True)
+    with tempfile.NamedTemporaryFile(suffix='.kicad_pcb') as f:
+        args = mesh_args(db, coil_id, mesh_type, mesh_file, f.name)
+        tqdm.tqdm.write(' '.join(map(str, args)))
+        logfile = log_dir / mesh_file.with_suffix('.log').name
+        logfile.parent.mkdir(exist_ok=True)
+        try:
+            res = subprocess.run(args, check=True, capture_output=True, text=True)
+            logfile.write_text(res.stdout + res.stderr)
+
+        except subprocess.CalledProcessError as e:
+            print('Mesh generation failed with exit code {e.returncode}', file=sys.stderr)
+            logfile.write_text(e.stdout + e.stderr)
+            print(e.stdout + e.stderr)
+            raise
+
+    return mesh_file
+
+
+@click.group()
+@click.option('-d', '--database', default='coil_parameters.sqlite3')
+@click.pass_context
+def cli(ctx, database):
+    ctx.ensure_object(dict)
+    def connect():
+        db = sqlite3.connect(database)
+        db.row_factory = sqlite3.Row
+        return db
+    ctx.obj['db_connect'] = connect
+    
+
+@cli.command()
+@click.pass_context
+def list_runs(ctx):
+    for row in ctx.obj['db_connect']().execute('SELECT * FROM runs ORDER BY timestamp').fetchall():
+        print(row['run_id'], row['timestamp'], row['version'])
+
+
+@cli.command()
+@click.pass_context
+def list_runs(ctx):
+    for row in ctx.obj['db_connect']().execute('SELECT * FROM runs ORDER BY timestamp').fetchall():
+        print(row['run_id'], row['timestamp'], row['version'])
+
+
+@cli.command()
+@click.option('-r', '--run-id')
+@click.option('-m', '--mesh-dir', default='meshes')
+@click.pass_context
+def list_coils(ctx, run_id, mesh_dir):
+    db = ctx.obj['db_connect']()
+    if run_id is None:
+        run_id, = db.execute('SELECT run_id FROM runs ORDER BY timestamp DESC LIMIT 1').fetchone()
+    timestamp, = db.execute('SELECT timestamp FROM runs WHERE run_id=?', (run_id,)).fetchone()
+    mesh_dir = pathlib.Path(mesh_dir)
+
+    print(f'Listing meshes for run {run_id} at {timestamp}')
+    print()
+
+    keys = {'gen.turns': 'N',
+            'gen.twists': 'T',
+            'gen.single_layer': '1L',
+            'gen.inner_diameter': 'ID[mm]',
+            'gen.outer_diameter': 'OD[mm]',
+            'calculated_fill_factor': 'Fill factor',
+            'calculated_approximate_inductance': 'L [µH]',
+            'calculated_trace_length': 'track len [mm]',
+            'calculated_approximate_resistance': 'R [mΩ]'}
+    out = []
+    for row in db.execute('SELECT *, MAX(meshes.timestamp) FROM coils LEFT JOIN meshes ON coils.coil_id=meshes.coil_id WHERE run_id=? GROUP BY coils.coil_id, mesh_type ORDER BY meshes.timestamp', (run_id,)).fetchall():
+        if row['timestamp']:
+            if row['error']:
+                state = 'ERROR'
+            elif not (mesh_dir / row['filename']).is_file():
+                state = 'NOT FOUND'
+            else:
+                state = 'SUCCESS'
+        else:
+            state = 'NOT RUN'
+
+        params = dict(db.execute('SELECT key, value FROM results WHERE coil_id=?', (row['coil_id'],)).fetchall())
+
+        if 'calculated_approximate_inductance' in params:
+            params['calculated_approximate_inductance'] = f'{float(params["calculated_approximate_inductance"])*1e6:.02f}'
+
+        if 'calculated_trace_length' in params:
+            params['calculated_trace_length'] = f'{float(params["calculated_trace_length"])*1e3:.03f}'
+
+        if 'calculated_approximate_resistance' in params:
+            params['calculated_approximate_resistance'] = f'{float(params["calculated_approximate_resistance"])*1e3:.03f}'
+
+        if 'calculated_fill_factor' in params:
+            params['calculated_fill_factor'] = f'{float(params["calculated_fill_factor"]):.03f}'
+
+        out.append([row['coil_id'], row['mesh_type'], state, row['timestamp']] + [params.get(key, '-') for key in keys])
+
+    print(tabulate(out, headers=['coil', 'mesh', 'state', 'time'] + list(keys.values()), disable_numparse=True, stralign='right'))
+
+@cli.command()
+@click.argument('coil_id', type=int)
+@click.argument('mesh_type', type=click.Choice(['normal', 'split', 'mutual']))
+@click.option('--mesh-file', default='/tmp/test.msh')
+@click.option('--pcb-file', default='/tmp/test.kicad_pcb')
+@click.pass_context
+def cmdline(ctx, coil_id, mesh_type, mesh_file, pcb_file):
+    print(' '.join(mesh_args(ctx.obj['db_connect'](), coil_id, mesh_type, mesh_file, pcb_file)))
+
+@cli.group()
+@click.option('-r', '--run-id')
+@click.option('-l', '--log-dir', default='logs')
+@click.option('-m', '--mesh-dir', default='meshes')
+@click.pass_context
+def run(ctx, run_id, log_dir, mesh_dir):
+    if run_id is None:
+        run_id, = ctx.obj['db_connect']().execute('SELECT run_id FROM runs ORDER BY timestamp DESC LIMIT 1').fetchone()
+    ctx.obj['run_id'] = run_id
+    ctx.obj['log_dir'] = pathlib.Path(log_dir)
+    ctx.obj['mesh_dir'] = pathlib.Path(mesh_dir)
+
+
+@run.command()
+@click.option('-j', '--num-jobs', type=int, default=1, help='Number of jobs to run in parallel')
+@click.pass_context
+def generate_meshes(ctx, num_jobs):
+    db = ctx.obj['db_connect']()
+    rows = [row['coil_id'] for row in db.execute('SELECT coil_id FROM coils WHERE run_id=?', (ctx.obj['run_id'],)).fetchall()]
+    mesh_types = ['split', 'normal', 'mutual']
+
+    params = list(itertools.product(rows, mesh_types))
+    all_files = {get_mesh_file(db, ctx.obj['mesh_dir'], ctx.obj['run_id'], coil_id, mesh_type): (coil_id, mesh_type) for coil_id, mesh_type in params}
+    todo = [(coil_id, mesh_type) for f, (coil_id, mesh_type) in all_files.items() if not f.is_file()]
+
+    q = queue.Queue()
+    for elem in todo:
+        q.put(elem)
+
+    tq = tqdm.tqdm(total=len(todo))
+    def queue_worker():
+        try:
+            while True:
+                coil_id, mesh_type = q.get_nowait()
+                try:
+                    ensure_mesh(ctx.obj['db_connect'](), ctx.obj['mesh_dir'], ctx.obj['log_dir'], ctx.obj['run_id'], coil_id, mesh_type)
+                except subprocess.CalledProcessError:
+                    tqdm.tqdm.write(f'Error generating {mesh_type} mesh for {coil_id=}')
+                tq.update(1)
+                q.task_done()
+        except queue.Empty:
+            pass
+
+    tqdm.tqdm.write(f'Found {len(params)-len(todo)} meshes out of a total of {len(params)}.')
+    tqdm.tqdm.write(f'Processing the remaining {len(todo)} meshes on {num_jobs} workers in parallel.')
+    threads = []
+    for i in range(num_jobs):
+        t = threading.Thread(target=queue_worker, daemon=True)
+        t.start()
+        threads.append(t)
+    q.join()
+
+@run.command()
+@click.option('-j', '--num-jobs', type=int, default=1, help='Number of jobs to run in parallel')
+@click.pass_context
+def self_inductance(ctx, num_jobs):
+    db = ctx.obj['db_connect']()
+
+    q = queue.Queue()
+
+    def queue_worker():
+        try:
+            while True:
+                mesh_file, logfile = q.get_nowait()
+                with tempfile.TemporaryDirectory() as tmpdir:
+                    try:
+                        tqdm.tqdm.write(f'Processing {mesh_file}')
+                        res = subprocess.run(['python', '-m', 'coil_parasitics', 'inductance', '--sim-dir', tmpdir, mesh_file], check=True, capture_output=True)
+                        logfile.write_text(res.stdout+res.stderr)
+                    except subprocess.CalledProcessError as e:
+                        print(f'Error running simulation, rc={e.returncode}')
+                        logfile.write_text(e.stdout+e.stderr)
+                tq.update(1)
+                q.task_done()
+        except queue.Empty:
+            pass
+
+    num_meshes, num_params, num_completed = 0, 0, 0
+    for coil_id, in db.execute('SELECT coil_id FROM coils WHERE run_id=?', (ctx.obj['run_id'],)).fetchall():
+        num_params += 1
+        mesh_file = get_mesh_file(ctx.obj['db_connect'](), ctx.obj['mesh_dir'], ctx.obj['run_id'], coil_id, 'normal')
+        if mesh_file.is_file():
+            num_meshes += 1
+            logfile = ctx.obj['log_dir']  / (mesh_file.stem + '_elmer_self_inductance.log')
+            if logfile.is_file():
+                num_completed += 1
+            else:
+                q.put((mesh_file, logfile))
+
+    tqdm.tqdm.write(f'Found {num_meshes} meshes out of a total of {num_params} with {num_completed} completed simulations.')
+    tqdm.tqdm.write(f'Processing the remaining {num_meshes-num_completed} simulations on {num_jobs} workers in parallel.')
+
+    tq = tqdm.tqdm(total=num_meshes-num_completed)
+    threads = []
+    for i in range(num_jobs):
+        t = threading.Thread(target=queue_worker, daemon=True)
+        t.start()
+        threads.append(t)
+    q.join()
+
+@run.command()
+@click.pass_context
+def self_capacitance(ctx):
+    db = ctx.obj['db_connect']()
+    for coil_id, in tqdm.tqdm(db.execute('SELECT coil_id FROM coils WHERE run_id=?', (ctx.obj['run_id'],)).fetchall()):
+        mesh_file = get_mesh_file(ctx.obj['db_connect'](), ctx.obj['mesh_dir'], ctx.obj['run_id'], coil_id, 'normal')
+        if mesh_file.is_file():
+            logfile = ctx.obj['log_dir']  / (mesh_file.stem + '_elmer_self_capacitance.log')
+            with tempfile.TemporaryDirectory() as tmpdir:
+                try:
+                    res = subprocess.run(['python', '-m', 'coil_parasitics', 'self-capacitance', '--sim-dir', tmpdir, mesh_file], check=True, capture_output=True)
+                    logfile.write_text(res.stdout+res.stderr)
+                except subprocess.CalledProcessError as e:
+                    print(f'Error running simulation, rc={e.returncode}')
+                    logfile.write_text(e.stdout+e.stderr)
+
+
+if __name__ == '__main__':
+   cli()
+
diff --git a/twisted_coil_gen_twolayer.py b/twisted_coil_gen_twolayer.py
index 5f06c39..204e7aa 100644
--- a/twisted_coil_gen_twolayer.py
+++ b/twisted_coil_gen_twolayer.py
@@ -138,16 +138,19 @@ def traces_to_gmsh(traces, mesh_out, bbox, model_name='gerbonara_board', log=Tru
     trace_field = gmsh.model.mesh.field.add('BoundaryLayer')
     gmsh.model.mesh.field.setNumbers(trace_field, 'CurvesList', getCurves(*trace_tags.values()))
     gmsh.model.mesh.field.setNumber(trace_field, 'Size', 0.5)
-    gmsh.model.mesh.field.setNumber(trace_field, 'SizeFar', 10.0)
+    gmsh.model.mesh.field.setNumber(trace_field, 'SizeFar', 5.0)
+    #gmsh.model.mesh.field.setAsBackgroundMesh(trace_field)
 
-    substrate_field = gmsh.model.mesh.field.add('AttractorAnisoCurve')
-    gmsh.model.mesh.field.setNumbers(substrate_field, 'CurvesList', getCurves(substrate))
-    gmsh.model.mesh.field.setNumber(substrate_field, 'DistMax', 10)
-    gmsh.model.mesh.field.setNumber(substrate_field, 'DistMin', 0)
-    gmsh.model.mesh.field.setNumber(substrate_field, 'SizeMinNormal', board_thickness/3)
-    gmsh.model.mesh.field.setNumber(substrate_field, 'SizeMaxNormal', 10.0)
-    gmsh.model.mesh.field.setNumber(substrate_field, 'SizeMinTangent', 0.5)
-    gmsh.model.mesh.field.setNumber(substrate_field, 'SizeMaxTangent', 10.0)
+    substrate_field = gmsh.model.mesh.field.add('Box')
+    gmsh.model.mesh.field.setNumber(substrate_field, 'VIn', board_thickness)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'VOut', 10.0)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'XMin', x1)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'YMin', y1)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'ZMin', -board_thickness)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'XMax', x2)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'YMax', y2)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'ZMax', 0)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'Thickness', 2*board_thickness)
 
     background_field = gmsh.model.mesh.field.add('MinAniso')
     gmsh.model.mesh.field.setNumbers(background_field, 'FieldsList', [trace_field, substrate_field])
@@ -339,17 +342,19 @@ def traces_to_gmsh_mag(traces, mesh_out, bbox, model_name='gerbonara_board', log
     trace_field = gmsh.model.mesh.field.add('BoundaryLayer')
     gmsh.model.mesh.field.setNumbers(trace_field, 'CurvesList', getCurves(toplevel_tag))
     gmsh.model.mesh.field.setNumber(trace_field, 'Size', 0.5)
-    gmsh.model.mesh.field.setNumber(trace_field, 'SizeFar', 10.0)
+    gmsh.model.mesh.field.setNumber(trace_field, 'SizeFar', 5.0)
     #gmsh.model.mesh.field.setAsBackgroundMesh(trace_field)
 
-    substrate_field = gmsh.model.mesh.field.add('AttractorAnisoCurve')
-    gmsh.model.mesh.field.setNumbers(substrate_field, 'CurvesList', getCurves(substrate))
-    gmsh.model.mesh.field.setNumber(substrate_field, 'DistMax', 10)
-    gmsh.model.mesh.field.setNumber(substrate_field, 'DistMin', 0)
-    gmsh.model.mesh.field.setNumber(substrate_field, 'SizeMinNormal', board_thickness/3)
-    gmsh.model.mesh.field.setNumber(substrate_field, 'SizeMaxNormal', 10.0)
-    gmsh.model.mesh.field.setNumber(substrate_field, 'SizeMinTangent', 0.5)
-    gmsh.model.mesh.field.setNumber(substrate_field, 'SizeMaxTangent', 10.0)
+    substrate_field = gmsh.model.mesh.field.add('Box')
+    gmsh.model.mesh.field.setNumber(substrate_field, 'VIn', board_thickness)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'VOut', 10.0)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'XMin', x1)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'YMin', y1)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'ZMin', -board_thickness)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'XMax', x2)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'YMax', y2)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'ZMax', 0)
+    gmsh.model.mesh.field.setNumber(substrate_field, 'Thickness', 2*board_thickness)
 
     background_field = gmsh.model.mesh.field.add('MinAniso')
     gmsh.model.mesh.field.setNumbers(background_field, 'FieldsList', [trace_field, substrate_field])