nodemcu-firmware/components/base_nodemcu/uart.c

// Module for interfacing with serial

#include "module.h"
#include "lauxlib.h"
#include "platform.h"
#include "driver/console.h"

#include <stdint.h>
#include <string.h>

extern uart_status_t uart_status[NUM_UART];

static lua_State *gL = NULL;
bool run_input = true;
bool uart_on_data_cb(unsigned id, const char *buf, size_t len){
  if(!buf || len==0)
    return false;
  if(uart_status[id].receive_rf == LUA_NOREF)
    return false;
  if(!gL)
    return false;

  lua_rawgeti(gL, LUA_REGISTRYINDEX, uart_status[id].receive_rf);
  lua_pushlstring(gL, buf, len);
  lua_pcall(gL, 1, 0, 0);
  return !run_input;
}

bool uart_on_error_cb(unsigned id, const char *buf, size_t len){
  if(!buf || len==0)
    return false;
  if(uart_status[id].error_rf == LUA_NOREF)
    return false;
  if(!gL)
    return false;

  lua_rawgeti(gL, LUA_REGISTRYINDEX, uart_status[id].error_rf);
  lua_pushlstring(gL, buf, len);
  lua_pcall(gL, 1, 0, 0);
  return true;
}

// Lua: uart.on([id], "method", [number/char], function, [run_input])
static int uart_on( lua_State* L )
{
  unsigned id = CONSOLE_UART;
  size_t sl, el;
  int32_t run = 1;
  uint8_t stack = 1;
  const char *method;
  uart_status_t *us;
  
  if( lua_isnumber( L, stack ) ) {
    id = ( unsigned )luaL_checkinteger( L, stack );
    MOD_CHECK_ID( uart, id );
    stack++;
  }
  us = & uart_status[id];
  method = luaL_checklstring( L, stack, &sl );
  stack++;
  if (method == NULL)
    return luaL_error( L, "wrong arg type" );

  if( lua_type( L, stack ) == LUA_TNUMBER )
  {
    us->need_len = ( uint16_t )luaL_checkinteger( L, stack );
    stack++;
    us->end_char = -1;
    if( us->need_len > 255 ){
      us->need_len = 255;
      return luaL_error( L, "wrong arg range" );
    }
  }
  else if(lua_isstring(L, stack))
  {
    const char *end = luaL_checklstring( L, stack, &el );
    stack++;
    if(el!=1){
      return luaL_error( L, "wrong arg range" );
    }
    us->end_char = (int16_t)end[0];
    us->need_len = 0;
  }

  // luaL_checkanyfunction(L, stack);
  if (lua_type(L, stack) == LUA_TFUNCTION || lua_type(L, stack) == LUA_TLIGHTFUNCTION){
    if ( lua_isnumber(L, stack+1) ){
      run = lua_tointeger(L, stack+1);
    }
    lua_pushvalue(L, stack);  // copy argument (func) to the top of stack
  } else {
    lua_pushnil(L);
  }
  if(sl == 4 && strcmp(method, "data") == 0){
    if(id == CONSOLE_UART)
      run_input = true;
    if(us->receive_rf != LUA_NOREF){
      luaL_unref(L, LUA_REGISTRYINDEX, us->receive_rf);
      us->receive_rf = LUA_NOREF;
    }
    if(!lua_isnil(L, -1)){
      us->receive_rf = luaL_ref(L, LUA_REGISTRYINDEX);
      gL = L;
      if(id == CONSOLE_UART && run==0)
        run_input = false;
    } else {
      lua_pop(L, 1);
    }
  } else if(sl == 5 && strcmp(method, "error") == 0){
    if(us->error_rf != LUA_NOREF){
      luaL_unref(L, LUA_REGISTRYINDEX, us->error_rf);
      us->error_rf = LUA_NOREF;
    }
    if(!lua_isnil(L, -1)){
      us->error_rf = luaL_ref(L, LUA_REGISTRYINDEX);
      gL = L;
    } else {
      lua_pop(L, 1);
    }
  } else {
    lua_pop(L, 1);
    return luaL_error( L, "method not supported" );
  }
  return 0; 
}

bool uart0_echo = true;
// Lua: actualbaud = setup( id, baud, databits, parity, stopbits, echo )
static int uart_setup( lua_State* L )
{
  unsigned id, databits, parity, stopbits, echo = 1;
  uint32_t baud, res;
  uart_pins_t pins;
  
  id = luaL_checkinteger( L, 1 );
  MOD_CHECK_ID( uart, id );
  baud = luaL_checkinteger( L, 2 );
  databits = luaL_checkinteger( L, 3 );
  parity = luaL_checkinteger( L, 4 );
  stopbits = luaL_checkinteger( L, 5 );
  if(id == CONSOLE_UART && lua_isnumber(L,6)){
    echo = lua_tointeger(L,6);
    if(echo!=0)
      uart0_echo = true;
    else
      uart0_echo = false;
  } else if(id != CONSOLE_UART && lua_istable( L, 6 )) {
      lua_getfield (L, 6, "tx");
      pins.tx_pin = luaL_checkint(L, -1);
      lua_getfield (L, 6, "rx");
      pins.rx_pin = luaL_checkint(L, -1);
      lua_getfield (L, 6, "cts");
      pins.cts_pin = luaL_optint(L, -1, -1);
      lua_getfield (L, 6, "rts");
      pins.rts_pin = luaL_optint(L, -1, -1);
      
      lua_getfield (L, 6, "tx_inverse");
      pins.tx_inverse = lua_toboolean(L, -1);
      lua_getfield (L, 6, "rx_inverse");
      pins.rx_inverse = lua_toboolean(L, -1);
      lua_getfield (L, 6, "cts_inverse");
      pins.cts_inverse = lua_toboolean(L, -1);
      lua_getfield (L, 6, "rts_inverse");
      pins.rts_inverse = lua_toboolean(L, -1);
      
      lua_getfield (L, 6, "flow_control");
      pins.flow_control = luaL_optint(L, -1, PLATFORM_UART_FLOW_NONE);
  }

  res = platform_uart_setup( id, baud, databits, parity, stopbits, &pins );
  lua_pushinteger( L, res );
  return 1;
}

// Lua: write( id, string1, [string2], ..., [stringn] )
static int uart_write( lua_State* L )
{
  unsigned id;
  const char* buf;
  size_t len;
  int total = lua_gettop( L ), s;
  
  id = luaL_checkinteger( L, 1 );
  MOD_CHECK_ID( uart, id );
  for( s = 2; s <= total; s ++ )
  {
    if( lua_type( L, s ) == LUA_TNUMBER )
    {
      len = lua_tointeger( L, s );
      if( len > 255 )
        return luaL_error( L, "invalid number" );
      platform_uart_send( id, (uint8_t)len );
    }
    else
    {
      luaL_checktype( L, s, LUA_TSTRING );
      buf = lua_tolstring( L, s, &len );
      platform_uart_send_multi( id, buf, len );
    }
  }
  platform_uart_flush( id );
  return 0;
}

// Lua: stop( id )
static int uart_stop( lua_State* L )
{
  unsigned id;
  id = luaL_checkinteger( L, 1 );
  MOD_CHECK_ID( uart, id );
  platform_uart_stop( id );
  return 0;
}

// Lua: start( id )
static int uart_start( lua_State* L )
{
  unsigned id;
  int err;
  id = luaL_checkinteger( L, 1 );
  MOD_CHECK_ID( uart, id );
  err = platform_uart_start( id );
  lua_pushboolean( L, err == 0 );
  return 1;
}

// Module function map
static const LUA_REG_TYPE uart_map[] =  {
  { LSTRKEY( "setup" ), LFUNCVAL( uart_setup ) },
  { LSTRKEY( "write" ), LFUNCVAL( uart_write ) },
  { LSTRKEY( "start" ), LFUNCVAL( uart_start ) },
  { LSTRKEY( "stop" ), LFUNCVAL( uart_stop ) },
  { LSTRKEY( "on" ),    LFUNCVAL( uart_on ) },
  { LSTRKEY( "STOPBITS_1" ),   LNUMVAL( PLATFORM_UART_STOPBITS_1 ) },
  { LSTRKEY( "STOPBITS_1_5" ), LNUMVAL( PLATFORM_UART_STOPBITS_1_5 ) },
  { LSTRKEY( "STOPBITS_2" ),   LNUMVAL( PLATFORM_UART_STOPBITS_2 ) },
  { LSTRKEY( "PARITY_NONE" ),  LNUMVAL( PLATFORM_UART_PARITY_NONE ) },
  { LSTRKEY( "PARITY_EVEN" ),  LNUMVAL( PLATFORM_UART_PARITY_EVEN ) },
  { LSTRKEY( "PARITY_ODD" ),   LNUMVAL( PLATFORM_UART_PARITY_ODD ) },
  { LSTRKEY( "FLOWCTRL_NONE" ),   LNUMVAL( PLATFORM_UART_FLOW_NONE ) },
  { LSTRKEY( "FLOWCTRL_CTS" ),   LNUMVAL( PLATFORM_UART_FLOW_CTS ) },
  { LSTRKEY( "FLOWCTRL_RTS" ),   LNUMVAL( PLATFORM_UART_FLOW_RTS ) },
  { LNILKEY, LNILVAL }
};

int luaopen_uart( lua_State *L ) {
  uart_status_t *us;
  for(int id = 0; id < NUM_UART; id++) {
    us = & uart_status[id];
    us->receive_rf = LUA_NOREF;
  us->error_rf = LUA_NOREF;
    us->need_len = 0;
    us->end_char = -1;
  }
  return 0;
}

NODEMCU_MODULE(UART, "uart", uart_map, luaopen_uart);