From 265011de83a4c59a57f0cd5441f308add9743820 Mon Sep 17 00:00:00 2001
From: Martin Preuss <martin@aquamaniac.de>
Date: Thu, 19 Jan 2023 22:07:45 +0100
Subject: [PATCH] Added COM_EnqueuePing.

---
 avr/com.asm | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/avr/com.asm b/avr/com.asm
index be5b9db..7be882e 100644
--- a/avr/com.asm
+++ b/avr/com.asm
@@ -25,6 +25,8 @@
 .equ COM_REPEAT_IMPORTANT         = 64
 .equ COM_REPEAT_VITAL             = 255
 
+.equ COM_CMD_PING                 = 1
+
 
 ; ***************************************************************************
 ; data
@@ -153,6 +155,45 @@ COM_EnqueuePacket_error:
   ret
 
 
+; ---------------------------------------------------------------------------
+; Enqueue a PING packet.
+;
+; IN:
+; - R17: destination address
+; OUT:
+; - CFLAG: set if okay, clear otherwise
+; MODIFIED REGS:
+
+COM_EnqueuePing:
+  ldi yl, LOW(comRingBuffer)
+  ldi yh, HIGH(comRingBuffer)
+  ldi r16, 3+2                 ; 3 bytes for buffer length, flags and destination address, src address, cmd, 
+  push r17
+    rcall RingBuffer_Alloc
+  pop r17
+  brcc COM_EnqueuePing_error
+  mov r18, r16
+  mov r20, r16                  ; r20: start of packet in ring buffer
+  ldd r19, y+RINGBUFFER_OFFS_MAXSIZE
+  ldi r16, 3+2
+  rcall RingBuffer_Write       ; write length
+  clr r16
+  rcall RingBuffer_Write       ; write flags
+  mov r16, r17
+  rcall RingBuffer_Write       ; write dest addr
+  ldi r16, COM_CMD_PING
+  rcall RingBuffer_Write       ; write cmd
+  mov r18, r20
+  ldi r20, COM_REPEAT_INFO
+  rcall COM_EnqueuePacket
+  brcc COM_EnqueuePing_error
+  sec
+  ret
+COM_EnqueuePing_error:
+  clc
+  ret
+
+
 
 ; ---------------------------------------------------------------------------
 ; comHandleNextPacketInRingbuffer