com2w: added some recovery code, improved protocol.

after sending a byte wait for the same time when sending the last bit as
with the other bits (otherwise the last bit might get lost by slower
devices).

avr/modules/com2w/com2w.asm

@@ -369,6 +369,8 @@ com2wSendByte_sent:
     brne com2wSendByte_loop
     out SREG, r15
   pop r15
+  rcall com2wWaitTime2                       ; wait for shorter time (R22)
+  M_COM2WDATASETHIGH                         ; ensure data line is high
   ret
 ; @end
 
@@ -435,6 +437,7 @@ com2wRecvMsg_eIo:
   ldi r16, NET_IFACE_OFFS_ERR_IO_LOW
 com2wRecvMsg_incCounterRet:
   rcall NET_Interface_IncCounter16        ; (R24, R25)
+  rcall com2wRecvByteWaitForQuietClk      ; (r18, r20, r22)
 com2wRecvMsg_clcRet:
   clc
 com2wRecvMsg_end:
@@ -443,6 +446,32 @@ com2wRecvMsg_end:
 
 
 
+; ---------------------------------------------------------------------------
+; @routine com2wRecvByteWaitForQuietClk
+;
+; Wait until the clock line is consistently high for 1ms.
+;
+; @clobbers r18, r20, r22
+
+com2wRecvByteWaitForQuietClk:
+  ldi r18, 200
+com2wRecvByteWaitForQuietClk_loop:
+      ldi r20, 100                          ; wait up to 1ms for clock high (R20, R22)
+      rcall com2wWaitForClockLowMulti10Us
+      brcs com2wRecvByteWaitForQuietClk_waitForLow
+      dec r18
+    brne com2wRecvByteWaitForQuietClk_loop
+    rjmp com2wRecvByteWaitForQuietClk_ret
+com2wRecvByteWaitForQuietClk_waitForLow:
+    ldi r20, 100                          ; wait up to 1ms for clock low (R20, R22)
+    rcall com2wWaitForClockLowMulti10Us
+    brcc com2wRecvByteWaitForQuietClk_ret ; not low within 1ms, assume line is quiet
+  brne com2wRecvByteWaitForQuietClk_loop
+com2wRecvByteWaitForQuietClk_ret:
+  ret
+
+
+
 ; ---------------------------------------------------------------------------
 ; @routine com2wRecvByte
 ;
@@ -455,10 +484,10 @@ com2wRecvByte:
   clr r16
 com2wRecvByte_loop:
     ldi r20, 50                          ; wait up to 500us for clock low
-    rcall com2wWaitForClockLowMulti10Us  ; (R16, R20, R22)
+    rcall com2wWaitForClockLowMulti10Us  ; (R20, R22)
     brcc com2wRecvByte_end
-    ldi r20, 50                          ; wait up to 500us for clock high
+    ldi r20, 100                          ; wait up to 1ms for clock high
-    rcall com2wWaitForClockHighMulti10Us ; (R16, R20, R22)
+    rcall com2wWaitForClockHighMulti10Us ; (R20, R22)
     brcc com2wRecvByte_end
     ; handle received bit
     inr r18, COM_DATA_INPUT

avr/modules/flash/io_com2w.asm

@@ -12,9 +12,8 @@
 
 
 
-
+.equ COM2W_WAITTIME1 = 25000
-.equ COM2W_WAITTIME1 = 17000
+.equ COM2W_WAITTIME2 = 15000
-.equ COM2W_WAITTIME2 = 10000
 
 
 
@@ -219,6 +218,8 @@ com2wSendByte_sent:
     rcall com2wWaitTime2                      ; shorter wait period (R22)
     dec r17
   brne com2wSendByte_loop
+  rcall com2wWaitTime2                        ; shorter wait period (R22)
+  rcall com2wDataSetHigh
   ret
 ; @end