ebus-racket: layer7: parse bit,data1b,data2b

2 files changed, 99 insertions, 7 deletions

diff --git a/ebus-racket/layer7-test.rkt b/ebus-racket/layer7-test.rkt
new file mode 100644
index 0000000..9654f06
--- /dev/null
+++ b/ebus-racket/layer7-test.rkt
@@ -0,0 +1,46 @@
+#lang racket
+(require rackunit
+         rackunit/text-ui
+         "layer2.rkt"
+         "layer7.rkt")
+
+(define layer7-test
+  (test-suite
+   "Tests for Ebus Layer 7 Parser"
+   (test-case
+    "Test sample Master-Master Paket"
+    (let*
+        ([paket (layer2-read-ebus (open-input-bytes (bytes
+                                                     170 ; SYN
+                                                     170 
+                                                     003 ; Source 
+                                                     241 ; Destination
+                                                     008 ; primaryCommand
+                                                     000 ; secondaryCommand
+                                                     008 ; payloadLength
+                                                     128 ; p1
+                                                     040 ; p2
+                                                     230 ; p3
+                                                     002 ; p4
+                                                     200 ; p5
+                                                     002 ; p6
+                                                     000 ; p7
+                                                     010 ; p8
+                                                     128 ; CRC
+                                                     000 ; ACK
+                                                     170 ; SYN
+                                                     170)))]
+         [fields (layer7-paket-fields paket)])
+      (check-true (= 5 (length fields)) "Anzahl der gelesenen Felder")
+      (for ([field fields])
+        (display field)
+        (display "\n")
+        (cond ((= (list-ref field 2) 0) (check-equal? (list-ref field 3) 40.5 "Wert TK_soll"))
+              ((= (list-ref field 2) 2) (check-equal? (list-ref field 3) 2.8984375 "Wert TA_ist"))
+              ((= (list-ref field 2) 4) (check-equal? (list-ref field 3) 200 "Wert L_zwang"))
+              ((= (list-ref field 2) 5) (check-equal? (list-ref field 3) 0 "Wert Status"))
+              ((= (list-ref field 2) 6) (check-equal? (list-ref field 3) 10 "Wert TB_soll")))))) ;end test-case
+   ))
+
+
+(run-tests layer7-test)
\ No newline at end of file
diff --git a/ebus-racket/layer7.rkt b/ebus-racket/layer7.rkt
index 5b8f496..8f8f39e 100644
--- a/ebus-racket/layer7.rkt
+++ b/ebus-racket/layer7.rkt
@@ -1,16 +1,19 @@
 #lang racket
-(require (planet lizorkin/sxml:2:1/sxml))
-(require (planet lizorkin/ssax:2:0/ssax))
+(require (planet lizorkin/sxml:2:1/sxml)
+         (planet lizorkin/ssax:2:0/ssax)
+         "layer2.rkt")
 
 (define definition
   (ssax:xml->sxml (open-input-file "../ebus-xml/ebus.xml")
                   '[(#f . "http://xapek.org/ebus/0.1")]))
 
 
-(define (ebus-paket primaryCommand secondaryCommand)
-  ((sxpath (string-append "//packet[@primary=" (number->string primaryCommand)
-                          " and @secondary=" (number->string secondaryCommand) "]"))
-           definition))
+(define (paket ebus-paket)
+  (let ([primaryCommand (layer2-ebus-paket-primaryCommand ebus-paket)]
+        [secondaryCommand (layer2-ebus-paket-secondaryCommand ebus-paket)])
+    ((sxpath (string-append "//packet[@primary=" (number->string primaryCommand)
+                            " and @secondary=" (number->string secondaryCommand) "]"))
+     definition)))
 
 ;; returns the full device-definition
 (define (device address)
@@ -21,6 +24,49 @@
 (define (device-name address)
   ((sxpath "@name/text()") (device address)))
 
-(provide (prefix-out layer7- ebus-paket)
+
+(define (paket-fields ebus-paket)
+  (let* ([paket-definition (paket ebus-paket)]
+         [paket-name (first ((sxpath "@name/text()") paket-definition))]
+         [fields ((sxpath "fields/*") paket-definition)]
+         [values (for/list ([field fields])
+                        (let ([datatype ((sxpath "name()") field)]
+                              [name (string-append paket-name "." (first ((sxpath "@name/text()") field)))]
+                              [offset (string->number (first ((sxpath "@offset/text()") field)))])
+                          (cond ((string=? "bit" datatype)
+                                 (list name datatype offset
+                                       (field-decoder-bit (list-ref (layer2-ebus-paket-payload ebus-paket) offset))))
+                                ((string=? "data1b" datatype)
+                                 (list name datatype offset
+                                       (field-decoder-data1b (list-ref (layer2-ebus-paket-payload ebus-paket) offset))))
+                                ((string=? "data2b" datatype)
+                                 (list name datatype offset
+                                       (field-decoder-data2b (list-ref (layer2-ebus-paket-payload ebus-paket) offset)
+                                                             (list-ref (layer2-ebus-paket-payload ebus-paket) (+ offset 1)))))
+                                (else (display (string-append "unknown datatype: " datatype))
+                                      (void)))
+                          ))])
+    ; filter invalid values
+    (for/list ([value values] #:when (not (void? value)))
+      value)))
+  
+;; type bit
+(define (field-decoder-bit value)
+  (cond ((= value 1) 1)
+        (else 0)))
+
+;; type data1b
+(define (field-decoder-data1b value)
+  value)
+
+;; type data2b
+(define (field-decoder-data2b lowByte highByte)
+  (cond ((= (bitwise-and highByte 128) 128)
+         (* -1 (+ (+ 256 (bitwise-not highByte))
+                  (/ (+ 256 (bitwise-not (+ lowByte 1))) 256.0))))
+         (else (+ highByte (/ lowByte 256.0)))))
+
+(provide (prefix-out layer7- paket)
+         (prefix-out layer7- paket-fields)
          (prefix-out layer7- device)
          (prefix-out layer7- device-name))
\ No newline at end of file