lua serialRead (#7520)

Lua serial read

radio/src/lua/api_general.cpp

@@ -66,6 +66,10 @@
   { "EVT_"#xxx"_LONG", EVT_KEY_LONG(yyy) }, \
   { "EVT_"#xxx"_REPT", EVT_KEY_REPT(yyy) }
 
+#if defined(LUA) && !defined(CLI)
+Fifo<uint8_t, LUA_FIFO_SIZE> * luaRxFifo = nullptr;
+#endif
+
 /*luadoc
 @function getVersion()
 
@@ -1615,6 +1619,53 @@ static int luaSerialWrite(lua_State * L)
   return 0;
 }
 
+/*luadoc
+@function serialRead([num])
+@param num (optional): maximum number of bytes to read.
+                       If non-zero, serialRead will read up to num characters from the buffer.
+                       If 0 or left out, serialRead will read up to and including the first newline character or the end of the buffer.
+                       Note that the returned string may not end in a newline if this character is not present in the buffer.
+
+@retval str string. Empty if no new characters were available.
+
+Reads characters from the serial port. The string is allowed to contain any character, including 0.
+
+@status current Introduced in TODO
+*/
+static int luaSerialRead(lua_State * L)
+{
+  int num = luaL_optunsigned(L, 1, 0);
+
+#if defined(LUA) && !defined(CLI)
+  if (!luaRxFifo) {
+    luaRxFifo = new Fifo<uint8_t, LUA_FIFO_SIZE>();
+    if (!luaRxFifo) {
+      lua_pushlstring(L, "", 0);
+      return 1;
+    }
+  }
+  uint8_t str[LUA_FIFO_SIZE];
+  uint8_t *p = str;
+  while (luaRxFifo->pop(*p)) {
+    p++;  // increment only when pop was successful
+    if (p - str >= LUA_FIFO_SIZE) {
+      break;  // Buffer full
+    }
+    if (num == 0 && (*(p - 1) == '\n' || *(p - 1) == '\r')) {
+      break;  // Found newline
+    }
+    if (num > 0 && p - str >= num) {
+      break;  // Requested number of characters reached
+    }
+  }
+  lua_pushlstring(L, (const char*)str, p - str);
+#else
+  lua_pushlstring(L, "", 0);
+#endif
+
+  return 1;
+}
+
 const luaL_Reg opentxLib[] = {
   { "getTime", luaGetTime },
   { "getDateTime", luaGetDateTime },
@@ -1662,6 +1713,7 @@ const luaL_Reg opentxLib[] = {
   { "multiBuffer", luaMultiBuffer },
 #endif
   { "serialWrite", luaSerialWrite },
+  { "serialRead", luaSerialRead },
   { nullptr, nullptr }  /* sentinel */
 };
 

radio/src/lua/lua_api.h

@@ -41,6 +41,11 @@ extern "C" {
   #endif
 #endif
 
+#if !defined(CLI)
+#define LUA_FIFO_SIZE 256
+extern Fifo<uint8_t, LUA_FIFO_SIZE> * luaRxFifo;
+#endif
+
 extern lua_State * lsScripts;
 extern lua_State * lsWidgets;
 extern bool luaLcdAllowed;

radio/src/targets/common/arm/stm32/aux_serial_driver.cpp

@@ -192,6 +192,19 @@ extern "C" void AUX_SERIAL_USART_IRQHandler(void)
     }
   }
 #endif
+#if defined(LUA) && !defined(CLI)
+  if (luaRxFifo && auxSerialMode == UART_MODE_LUA) {
+      // Receive
+      uint32_t status = AUX_SERIAL_USART->SR;
+      while (status & (USART_FLAG_RXNE | USART_FLAG_ERRORS)) {
+        uint8_t data = AUX_SERIAL_USART->DR;
+        if (!(status & USART_FLAG_ERRORS)) {
+          luaRxFifo->push(data);
+        }
+        status = AUX_SERIAL_USART->SR;
+      }
+    }
+#endif
 }
 #endif
 

radio/src/targets/common/arm/stm32/usbd_cdc.cpp

@@ -218,11 +218,18 @@ static uint16_t VCP_DataRx (uint8_t* Buf, uint32_t Len)
 
 #if defined(CLI)
   //copy data to the application FIFO
-  for (uint32_t i = 0; i < Len; i++)
-  {
+  for (uint32_t i = 0; i < Len; i++) {
     cliRxFifo.push(Buf[i]);
   }
 #endif
+#if defined(LUA) && !defined(CLI)
+  // copy data to the LUA FIFO
+  if (luaRxFifo) {
+    for (uint32_t i = 0; i < Len; i++) {
+      luaRxFifo->push(Buf[i]);
+    }
+  }
+#endif
 
   return USBD_OK;
 }