Better layer support; disable L2 for now.

Need press/release tracking before sticky layers will work.

Makefile

@@ -16,13 +16,13 @@ test: ; racket test.rkt
 
 clean: ; -rm -f $(TARGET){,.hex} *.o *.elf *.s
 
-count: ; cloc *.scm
+count: ; cloc menelaus.scm keycodes.scm
 
 $(TARGET).hex: $(TARGET).elf
 	avr-size $(TARGET).elf
 	avr-objcopy --output-target=ihex $(TARGET).elf $(TARGET).hex
 
-%.s: %.scm
+$(TARGET).s: $(TARGET).scm layout.scm keycodes.scm
 	microscheme -m LEO $(TARGET).scm
 
 %.elf: %.s usb_keyboard.s

README.md

@@ -11,13 +11,15 @@ A firmware for the
 * Multiple layers, momentary and sticky (limited only by memory)
 * Combo keys (a single keystroke can send a modifier and a non-modifier)
 * Bind arbitrary Scheme functions to a key
-* ~255 lines of code
+* ~200 lines of code
 
 ## Usage
 
 This currently requires Microscheme with the addition of
-`vector-copy!` which at the time of this writing is only available on
-[this branch](https://github.com/ryansuchocki/microscheme/pull/31).
+`vector-copy!` which at the time of this writing is only on the master branch.
+
+Also requires [avrdude](https://www.nongnu.org/avrdude/) for uploading
+to the device.
 
 Replace `/dev/ttyACM0` with the path your OS assigns to the USB
 bootloader of the microcontroller:
@@ -38,6 +40,8 @@ into Racket and simulates the GPIO functions with a test harness:
 
 ## Known bugs
 
+Still working out some quirks with sticky layers.
+
 If you hold the fn key, press a button (say Q) and then release fn
 without releasing Q, it will send a keycode for Q rather than simply
 leaving the previous fn+Q keycodes as held down.

layout.scm

@@ -1,29 +1,22 @@
 ;;; this is the multidvorak layout
 
 ;; we have to declare this up front and set it later because of circularity
-(define layers (vector #f #f #f))
+(define layers #f)
 (define current-layer #f)
 (define momentary-layer #f)
 
 (define (fn)
   (set! momentary-layer (vector-ref layers 1)))
 
-(define (set-layer-2)
-  (set! current-layer (vector-ref layers 2)))
-
-(define (set-layer-0)
-  (set! current-layer (vector-ref layers 0)))
-
-(define (set-layer-hard)
-  (set! current-layer (vector-ref layers 3)))
+(define (set-layer n)
+  (lambda () (set! current-layer (vector-ref layers n))))
 
 (define (reset)
   #f) ;; TODO: uh, seriously. I need this. how.
 
 ;;;; layers
 
-(vector-set! ; base
- layers 0
+(define base-layer
  (vector key-q key-w key-e key-r key-t key-backslash
          key-y key-u key-i key-o key-p
 
@@ -36,8 +29,7 @@
          key-esc key-tab mod-super mod-shift key-backspace mod-alt
          key-space fn key-quote key-left-bracket key-enter))
 
-(vector-set! ; fn
- layers 1
+(define fn-layer
  (vector (sft key-1) (sft key-2) key-up (sft key-dash) (sft key-equal) 0
          key-page-up key-7 key-8 key-9 (sft key-8)
 
@@ -47,25 +39,25 @@
          key-dash key-equal (sft key-9) (sft key-0) (sft key-7) mod-ctrl
          key-backtick key-1 key-2 key-3 key-backslash
 
-         set-layer-2 key-insert mod-super mod-shift key-backspace mod-alt
+         ;; still got some bugs in layering to work out! make this reset for now
+         reset ;; (set-layer 2)
+         key-insert mod-super mod-shift key-backspace mod-alt
          key-space fn key-e key-0 key-right-bracket))
 
-(vector-set! ; l2 (function keys, etc)
- layers 2
+(define l2-layer
  (vector key-insert key-home key-up key-end key-page-up 0
          key-up key-f7 key-f8 key-f9 key-f10
 
          key-delete key-left key-down key-right key-page-down 0
          key-down key-f4 key-f5 key-f6 key-f11
 
-         0 key-vol-up 0 0 reset mod-ctrl
-         set-layer-hard key-f1 key-f2 key-f3 key-f12
+         (set-layer 0) key-vol-up 0 0 reset mod-ctrl
+         (set-layer 4) key-f1 key-f2 key-f3 key-f12
 
          0 key-vol-down mod-super mod-shift key-backspace mod-alt
-         key-space set-layer-0 key-printscreen key-scroll-lock key-pause))
+         key-space 0 key-printscreen key-scroll-lock key-pause))
 
-(vector-set! ; hard dvorak
- layers 3
+(define hard-dvorak-layer
  (vector key-quote key-comma key-period key-p key-y key-backslash
          key-f key-g key-c key-r key-l
 
@@ -78,8 +70,7 @@
          key-esc key-tab mod-super mod-shift key-backspace mod-alt
          key-space fn key-quote key-left-bracket key-enter))
 
-(vector-set! ; hard dvorak fn
- layers 4
+(define hard-dvorak-fn-layer
  (vector (sft key-1) (sft key-2) key-up (sft key-left-bracket) (sft key-right-bracket) 0
          key-page-up key-7 key-8 key-9 (sft key-8)
 
@@ -89,5 +80,8 @@
          key-left-bracket key-right-bracket (sft key-9) (sft key-0) (sft key-7) mod-ctrl
          key-backtick key-1 key-2 key-3 key-backslash
 
-         set-layer-2 key-insert mod-super mod-shift key-backspace mod-alt
+         (set-layer 2) key-insert mod-super mod-shift key-backspace mod-alt
          key-space fn key-e key-0 key-right-bracket))
+
+(set! layers (vector base-layer fn-layer l2-layer
+                     hard-dvorak-layer hard-dvorak-fn-layer))

menelaus.scm

@@ -16,11 +16,11 @@
 (define (scan-key keys-pressed key-count row col)
   ;; pullup resistors mean a closed circuit is low rather than high
   (if (low? (vector-ref column-pins col))
-      (begin
       (if (<= key-count max-keys)
+          (begin
             (vector-set! keys-pressed key-count (offset-for row col))
-            #f)
             (+ key-count 1))
+          key-count)
       key-count))
 
 (define (scan-column keys-pressed key-count row columns-left)
@@ -47,7 +47,7 @@
 (define this-scan (vector 0 0 0 0 0 0 0))
 (define last-scan (vector 0 0 0 0 0 0 0))
 
-(define debounce-passes 8)
+(define debounce-passes 4)
 
 (define (debounce-matrix keys-pressed last-count passes-left)
   ;; older versions of microscheme don't have vector-copy!, only vector-copy
@@ -80,9 +80,7 @@
 (define (call-functions keys-pressed key-count)
   (if (< 0 key-count)
       (let ((code (lookup keys-pressed key-count)))
-        (if (procedure? code)
-            (code)
-            #f)
+        (and (procedure? code) (code))
         (call-functions keys-pressed (- key-count 1)))
       #f))
 
@@ -93,15 +91,14 @@
   (if (= 0 key-count)
       (vector->list keycodes)
       (let ((keycode (keycode-for keys-pressed key-count keycodes)))
-        (if keycode
-            (vector-set! keycodes key-count keycode)
-            #f)
+        (and keycode
+             (vector-set! keycodes key-count keycode))
         (keycodes-for keys-pressed (- key-count 1) keycodes))))
 
 ;;;;;;;;;;;;;;;;;;; showtime
 
 (define (init)
-  (set-layer-0)
+  (set! current-layer (vector-ref layers 0))
   (for-each-vector output row-pins)
   (for-each-vector high row-pins)
   (for-each-vector input column-pins)

test.rkt

@@ -68,6 +68,16 @@
     ((40 35 2) . (8 ,key-up 0 0 0 0 0))
     ;; releasing fn should leave the previously-pressed key on the fn layer!!!
     ;; ((2) . (0 ,key-up 0 0 0 0 0))
+    ;; changing to L2 (fn+esc)
+    ((40 33) . (0 0 0 0 0 0 0))
+    ;; fn+esc should stay on L2 across multiple scans
+    ((40 33) . (0 0 0 0 0 0 0))
+    ;; hitting an L2 key
+    ;; ((1) . (0 ,key-home 0 0 0 0 0))
+    ;; back to base (key above esc)
+    ;; ((22) . (0 0 0 0 0 0 0))
+    ;; base layer key
+    ((2) . (0 ,key-e 0 0 0 0 0))
     ))
 
 (define test-data (make-test-data))
@@ -80,7 +90,8 @@
         (cons (format "Expected ~s, got ~s~n" expected actual) failures)))
 
 (define (finish)
-  (printf (string-join failures "~n" #:before-first "~n" #:after-last "~n"))
+  (printf (string-join (reverse failures)
+                       "~n" #:before-first "~n" #:after-last "~n"))
   (exit (if (empty? failures) 0 1)))
 
 ;; we can perform our checks here and make changes to the pin state.