API

A (formal) overview of syntax

The syntax

The semantics

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Grow your circuit withmake-circuit

This syntax makes it easy to define a composite. The syntax is:

(make-circuit

#:external-pins (o1 o2)

#:vars ([a (R 22)]

[b (C 1)]

[c (crystal)])

#:connect (*- self.o1 a b c self.o2)

#:layout (hc-append a b c))

This declares a circuit, with external pins named o1 and o2 respectively. It contains a resistor, a capacitor, and a crystal, lined together linearly. In the meantime, the physical layout is defined as horizontally append the three components.

To make the circuit capable of using line connection syntax, define the left and right external pins and connect accordingly. E.g.

(define (Switch)

(make-circuit

#:vars ([it (SKRPACE010)])

#:external-pins (left right)

#:layout it

#:connect (list (*- self.left it.A1)

(*- self.right it.B1))))

Connection syntax and semantics

Composing circuit is the process of combining smaller circuits and atoms with netlist. There are 4 syntax for composing Composites. The return value is a Composite that contains the used components, and the external pin for the returned Composite is denoted as out.X.

The line connection:

(*- a b c)

Results in the netlist:

out.1 -- a.1

a.2 -- b.1

b.2 -- c.1

c.2 -- out.2

The split connection:

(*< a b c)

results in the netlist:

out.1 -- a.1 -- b.1 -- c.1

out.2 -- a.2 -- b.2 -- c.2

The vectorized connection:

(*= (a [p1 p2 p3])

([b.p1 c.p2 d.p3]))

results in the netlist:

a.p1 -- b.p1

a.p2 -- c.p2

a.p3 -- d.p3

Note that the vector supports two slightly different syntax: the component can be write once. I.e. (a [1 2 3]) is equivalent to ([a.1 a.2 a.3]).

And finally the netlist syntax:

(*+ ([a.1 b.1 c.1]

[a.2 b.3]))

results in the netlis:

a.1 -- b.1 -- c.1

a.2 -- b.3

Layout co-design

The layout is inspired by racket's functional picture library. The following combinators are provided:

The *-append family of functions append its arguments horizontally or vertically:

vl-append

vc-append

vr-append

ht-append

hc-append

hb-append

htl-append

hbl-append

The *-superimpose family of functions overlap its arguments.

lt-superimpose

lb-superimpose

lc-superimpose

ltl-superimpose

lbl-superimpose

rt-superimpose

rb-superimpose

rc-superimpose

rtl-superimpose

rbl-superimpose

ct-superimpose

cb-superimpose

cc-superimpose

ctl-superimpose

cbl-superimpose

You can also rotate or pin-over at a absolute location in terms of (x,y) coordinates:

(rotate item 3.14)

(pin-over base dx dy item)

Visualization and exporting

The layout can be visualized via

(show-layout my-circuit)

To export KiCAD files, use circuit-export:

(circuit-export fitboard

#:auto-place #t

#:formats '(kicad pdf dsn ses))

The arguments:

• #:auto-place determins whether to run placement engine. This requires a backend placement engine running on specific port (by default 8082)
• #:formats: this is a list of export formats
  • kicad: kicad_pcb file
  • pdf
  • dsn: Spectre DSN
  • ses: run freerouting on dsn. This requires dsn is exported, freerouting.jar executable can be found, and you are running a GUI session so that the freerouting.jar window can pop up (which means it cannot run in jupyter notebook)