Initial import

Author: fdu

README.md

@@ -0,0 +1,56 @@
+# ESP8266 Arduino Lua
+
+This Arduino library provides the [lua](https://www.lua.org/) 5.3.4 scripting engine for ESP8266 sketches. This allows dynamic execution of code on Arduino without having to compile and flash a new firmware. As an example, the following standard Arduino functions are available in lua scripts as bindings:
+* *pinMode()*
+* *digitalWrite()*
+* *delay()*
+* *millis()*
+* *print()* which redirects to *Serial.println()*
+
+## Installation into the Arduino IDE
+
+Download the content of this Github repository as a ZIP archive by clicking on *Clone or download* then *Download ZIP*. Follow the instructions on [installing additional Arduino libraries](https://www.arduino.cc/en/Guide/Libraries#toc4) and navigate to the file downloaded previously.
+
+## Arduino sketch examples
+
+After installing the library, some sketch examples are available from the *File* menu, then *Examples* and finally under *ESP8266-Arduino-Lua*. The examples include **ExecuteScriptFromSerial** which takes a lua script from the serial line and executes it:
+
+```
+# Enter the lua script and press Control-D when finished:
+print("My first test!")
+# Executing script:
+My first test!
+
+
+# Enter the lua script and press Control-D when finished:
+print("Current uptime: "..millis())
+# Executing script:
+Current uptime: 159926.0
+```
+
+## Lua script examples
+
+The lua language syntax is described in the [reference manual](https://www.lua.org/manual/). It is extended by the Arduino functions listed above.
+
+### Hello world
+
+```
+print("Hello world!")
+```
+
+### Blinking LED
+
+```
+pinLED = 2
+period = 500
+pinMode(pinLED, OUTPUT)
+while(true)
+do
+  print("LED on")
+  digitalWrite(pinLED, LOW)
+  delay(period)
+  print("LED off")
+  digitalWrite(pinLED, HIGH)
+  delay(period)
+end
+```

examples/ExecuteScriptFromSerial/ExecuteScriptFromSerial.ino

@@ -0,0 +1,33 @@
+#include <LuaWrapper.h>
+
+LuaWrapper lua;
+
+void setup() {
+  Serial.begin(115200);
+}
+
+void loop() {
+  String script = "";
+  char c = 0;
+  Serial.println();
+  Serial.println("# Enter the lua script and press Control-D when finished:");
+  while(1) {
+    if(Serial.available() > 0) {
+      c = Serial.read();
+      if(c == 4) {
+        break;
+      }
+      Serial.write(c);
+      script += c;
+      if(c == '\r') {
+        Serial.write('\n');
+        script += '\n';
+      }
+    }   
+  }
+  if(script.length() > 0) {
+    Serial.println();
+    Serial.println("# Executing script:");
+    Serial.println(lua.Lua_dostring(&script));
+  }
+}

examples/HelloWorld/HelloWorld.ino

@@ -0,0 +1,13 @@
+#include <LuaWrapper.h>
+
+LuaWrapper lua;
+
+void setup() {
+  Serial.begin(115200);
+  String script = String("print('Hello world!')");
+  Serial.println(lua.Lua_dostring(&script));
+}
+
+void loop() {
+
+}

examples/LuaError/LuaError.ino

@@ -0,0 +1,13 @@
+#include <LuaWrapper.h>
+
+LuaWrapper lua;
+
+void setup() {
+  Serial.begin(115200);
+  String script = String("thisFunctionDoesNotExistsSoThisWillFail()");
+  Serial.println(lua.Lua_dostring(&script));
+}
+
+void loop() {
+
+}

examples/RegisterFunction/RegisterFunction.ino

@@ -0,0 +1,18 @@
+#include <LuaWrapper.h>
+
+LuaWrapper lua;
+
+static int myFunction(lua_State *lua_state) {
+  Serial.println("Hi from my C function");
+}
+
+void setup() {
+  Serial.begin(115200);
+  lua.Lua_register("myFunction", (const lua_CFunction) &myFunction);
+  String script = String("myFunction()");
+  Serial.println(lua.Lua_dostring(&script));
+}
+
+void loop() {
+
+}

library.properties

@@ -0,0 +1,10 @@
+name=ESP8266-Arduino-Lua
+version=0.0.10
+author=Francois Dugast <[email protected]>
+maintainer=Francois Dugast <[email protected]>
+sentence=Lua scripting engine integrated in Arduino for ESP8266
+paragraph=
+category=Other
+url=https://github.com/fdu/ESP8266-Arduino-Lua
+architectures=esp8266
+includes=LuaWrapper.h

src/LuaWrapper.cpp

@@ -0,0 +1,61 @@
+#include "LuaWrapper.h"
+
+extern "C" {
+  static int lua_wrapper_pinMode(lua_State *lua) {
+    int a = luaL_checkinteger(lua, 1);
+    int b = luaL_checkinteger(lua, 2);
+    pinMode(a, b);
+  }
+
+  static int lua_wrapper_digitalWrite(lua_State *lua) {
+    int a = luaL_checkinteger(lua, 1);
+    int b = luaL_checkinteger(lua, 2);
+    digitalWrite(a, b);
+  }
+  
+  static int lua_wrapper_delay(lua_State *lua) {
+    int a = luaL_checkinteger(lua, 1);
+    delay(a);
+  }
+
+  static int lua_wrapper_print(lua_State *lua) {
+    String a = String(luaL_checkstring(lua, 1));
+    Serial.println(a);
+  }
+
+  static int lua_wrapper_millis(lua_State *lua) {
+    lua_pushnumber(lua, (lua_Number) millis());
+    return 1;
+  }
+}
+
+LuaWrapper::LuaWrapper() {
+  _state = luaL_newstate();
+  lua_register(_state, "pinMode", lua_wrapper_pinMode);
+  lua_register(_state, "digitalWrite", lua_wrapper_digitalWrite);
+  lua_register(_state, "delay", lua_wrapper_delay);
+  lua_register(_state, "print", lua_wrapper_print);
+  lua_register(_state, "millis", lua_wrapper_millis);
+}
+
+String LuaWrapper::Lua_dostring(const String *script) {
+  String scriptWithConstants = addConstants() + *script;
+  String result;
+  if (luaL_dostring(_state, scriptWithConstants.c_str())) {
+    result += "# lua error:\n" + String(lua_tostring(_state, -1));
+    lua_pop(_state, 1);
+  }
+  return result;
+}
+
+void LuaWrapper::Lua_register(const String name, const lua_CFunction function) {
+  lua_register(_state, name.c_str(), function);
+}
+
+String LuaWrapper::addConstants() {
+  String constants = "INPUT = " + String(INPUT) + "\r\n";
+  constants += "OUTPUT = " + String(OUTPUT) + "\r\n";
+  constants += "LOW = " + String(LOW) + "\r\n";
+  constants += "HIGH = " + String(HIGH) + "\r\n";
+  return constants;
+}

src/LuaWrapper.h

@@ -0,0 +1,20 @@
+#ifndef LUA_WRAPPER_H
+#define LUA_WRAPPER_H
+
+#include "Arduino.h"
+
+#define LUA_USE_C89
+#include "lua/lua.hpp"
+
+class LuaWrapper {
+  public:
+    LuaWrapper();
+    String Lua_dostring(const String *script);
+    void Lua_register(const String name, const lua_CFunction function);
+
+  private:
+    lua_State *_state;
+    String addConstants();
+};
+
+#endif