first commit

dev/ibus.cpp

@@ -0,0 +1,73 @@
+#include <string.h>
+
+#include "uart.h"
+#include "tick.h"
+
+#include "ibus.h"
+
+// IBUS: LEN(1)+CMD(1)+DATA(0..32)+CHSM(2)
+
+#define IBUS_LEN_MAX 32 // DATA(0..32)
+#define IBUS_LEN_PRO 3  // CMD(1)+CHSM(2)
+
+void IBUS_Init(unsigned long Baud)
+{
+  UART2_Init(Baud);
+}
+
+static const unsigned long Size = IBUS_LEN_MAX + IBUS_LEN_PRO;
+static char Buffer[Size];
+
+static char Pos = 0, Len = 0;
+static unsigned long CheckSum;
+
+static unsigned long Time;
+
+static bool Parse(IBUS_Data& Data, char byte)
+{
+  unsigned long wait = TICK_GetCount() - Time;
+  if (wait > 4) Len = 0; // Protocol synchronization lost !!!
+
+  if (!Len)
+  {
+    if (byte > IBUS_LEN_MAX || byte < IBUS_LEN_PRO) return false;
+    Pos = 0;
+    Len = byte - 1;
+    CheckSum = 0xFFFFUL - byte;
+    Time = TICK_GetCount();
+    return false;
+  }
+
+  Buffer[Pos++] = byte;
+  if (Pos <= Len - 2) CheckSum -= byte;
+
+  if (Pos < Len) return false;
+
+  unsigned long len = Len;
+  Len = 0;
+
+  unsigned short chsm = *(unsigned short*)(Buffer + (len - 2));
+
+  if (chsm != CheckSum) return false;
+
+  switch (Buffer[0])
+  {
+  case 0x40:
+  {
+    memcpy(&Data, Buffer + 1, len - 3 > sizeof(Data) ? sizeof(Data) : len - 3);
+    return true;
+  }
+  }
+  return false;
+}
+
+bool IBUS_Update(IBUS_Data& Data, bool& Off)
+{
+  char buf[Size];
+  unsigned long size = UART2_Recv(buf, Size);
+
+  bool done = false;
+  for (long a = 0; a < size; a++) done = Parse(Data, buf[a]);
+  Off=Data.SWD<1000;
+  return done;
+}