From 6833dfbf7c615f7b94b7996cc46af7751f529be9 Mon Sep 17 00:00:00 2001
From: Phil Hagelberg <phil@hagelb.org>
Date: Sun, 4 Jan 2015 15:06:19 -0800
Subject: [PATCH] Fully tested step 2: scanning one row.

---
 menelaus.scm | 53 +++++++++++++++++++---------------------------------
 1 file changed, 19 insertions(+), 34 deletions(-)

diff --git a/menelaus.scm b/menelaus.scm
index 9110258..81da1f2 100644
--- a/menelaus.scm
+++ b/menelaus.scm
@@ -1,44 +1,29 @@
 (include "keycodes.scm")
-(include "layout.scm")
 
-(define row-pins (list 0 1 2 3))
-(define column-pins (list 11 12 18 19 10 4 7 8 9 5 6))
+(define columns (list 0 1 2 3 4 5 6 7 8 9))
+(define column-pins (vector 11 12 18 19
+                            10 7 8 9 5 6))
+(define layout (vector key-a key-s key-d key-f key-g
+                       key-h key-j key-k key-l key-semicolon))
 
-(define (scan-column columns row-layout pressed)
-  (if (null? columns)
-      pressed
-      (scan-column (cdr columns)
-                   (cdr row-layout)
-                   (if (low? (car columns))
-                       (car row-layout)
-                       pressed))))
+(for-each output (list 0 1 2 3))
+(for-each high (list 0 1 3))
+(low 2)
 
-(define (scan-rows rows layout-rows pressed)
-  (if (null? rows)
-      pressed
-      (begin
-        (for-each high row-pins)
-        (low (car rows)) ; activate row
-        (scan-rows (cdr rows) (cdr layout-rows)
-                   (scan-column column-pins (car layout-rows) 0)))))
+(for-each-vector input column-pins)
+(for-each-vector high column-pins) ; activate pullup resistors
+
+(call-c-func "usb_init")
+(pause 200)
+
+(define (scan-column last n)
+  (if (low? (vector-ref column-pins n))
+      (vector-ref layout n)
+      last))
 
 (define (loop)
-  (let ((pressed (scan-rows row-pins layout 0)))
+  (let ((pressed (fold scan-column 0 columns)))
     (call-c-func "usb_send" 0 pressed 0 0 0 0 0))
   (loop))
 
-(define (init)
-  ;; leonardo pins only go up to 13, but a-star goes to 19
-  (set! arduino-ports (vector #x29 #x29 #x29 #x29 #x29 #x26 #x29 #x2C
-                              #x23 #x23 #x23 #x23 #x29 #x26
-                              #x23 #x23 #x23 #x29 #x2D #x2D))
-  (set! arduino-pins (vector 4 8 2 1 16 64 128 64 16 32 64 128 64 128
-                             8 2 4 32 65 128))
-  (for-each output row-pins)
-  (for-each input column-pins)
-  (for-each high column-pins) ; activate pullup resistors
-  (call-c-func "usb_init")
-  (pause 200))
-
-(init)
 (loop)