/* * Driver for Microchip MCP4725 12-bit digital to analog converter. */ #include "module.h" #include "lauxlib.h" #include "platform.h" #include "osapi.h" #define MCP4725_I2C_ADDR_BASE (0x60) #define MCP4725_I2C_ADDR_A0_MASK (0x01) // user configurable #define MCP4725_I2C_ADDR_A1_MASK (0x02) // hard wired at factory #define MCP4725_I2C_ADDR_A2_MASK (0x04) // hard wired at factory #define MCP4725_COMMAND_WRITE_DAC (0x40) #define MCP4725_COMMAND_WRITE_DAC_EEPROM (0x60) #define MCP4725_POWER_DOWN_NORMAL (0x00) #define MCP4725_POWER_DOWN_RES_1K (0x02) #define MCP4725_POWER_DOWN_RES_100K (0x04) #define MCP4725_POWER_DOWN_RES_500K (0x06) static const unsigned mcp4725_i2c_id = 0; static uint8 get_address(lua_State* L, uint8 i2c_address){ uint8 addr_temp = i2c_address; uint16 temp_var = 0; lua_getfield(L, 1, "A2"); if (!lua_isnil(L, -1)) { if( lua_isnumber(L, -1) ) { temp_var = lua_tointeger(L, -1); if(temp_var < 2){ temp_var = MCP4725_I2C_ADDR_A2_MASK & (temp_var << 2); addr_temp|=temp_var; } else return luaL_argerror( L, 1, "A2: Must be 0 or 1" ); } else { return luaL_argerror( L, 1, "A2: Must be number" ); } } lua_pop(L, 1); lua_getfield(L, 1, "A1"); if (!lua_isnil(L, -1)) { if( lua_isnumber(L, -1) ) { temp_var = lua_tointeger(L, -1); if(temp_var < 2){ temp_var = MCP4725_I2C_ADDR_A1_MASK & (temp_var << 1); addr_temp|=temp_var; } else return luaL_argerror( L, 1, "A1: Must be 0 or 1" ); } else { return luaL_argerror( L, 1, "A1: Must be number" ); } } lua_pop(L, 1); lua_getfield(L, 1, "A0"); if (!lua_isnil(L, -1)) { if( lua_isnumber(L, -1) ) { temp_var = lua_tointeger(L, -1); if(temp_var<2){ temp_var = MCP4725_I2C_ADDR_A0_MASK & (temp_var); addr_temp|=temp_var; } else return luaL_argerror( L, 1, "A0: Must be 0 or 1" ); } else { return luaL_argerror( L, 1, "A0: Must be number" ); } } lua_pop(L, 1); return addr_temp; } static int mcp4725_write(lua_State* L){ uint8 i2c_address = MCP4725_I2C_ADDR_BASE; uint16 dac_value = 0; uint8 cmd_byte = 0; if(lua_istable(L, 1)) { i2c_address = get_address(L, i2c_address); uint16 temp_var=0; lua_getfield(L, 1, "value"); if (!lua_isnil(L, -1)) { if( lua_isnumber(L, -1) ) { temp_var = lua_tointeger(L, -1); if(temp_var >= 0 && temp_var<=4095){ dac_value = temp_var<<4; } else return luaL_argerror( L, 1, "value: Valid range 0-4095" ); } else { return luaL_argerror( L, 1, "value: Must be number" ); } } else { return luaL_argerror( L, 1, "value: value is required" ); } lua_pop(L, 1); lua_getfield(L, 1, "save"); if (!lua_isnil(L, -1)) { if( lua_isboolean(L, -1) ) { if(lua_toboolean(L, -1)){ cmd_byte |= MCP4725_COMMAND_WRITE_DAC_EEPROM; } else{ cmd_byte |= MCP4725_COMMAND_WRITE_DAC; } } else { return luaL_argerror( L, 1, "save: must be boolean" ); } } else { cmd_byte |= MCP4725_COMMAND_WRITE_DAC; } lua_pop(L, 1); lua_getfield(L, 1, "pwrdn"); if (!lua_isnil(L, -1)) { if( lua_isnumber(L, -1) ) { temp_var = lua_tointeger(L, -1); if(temp_var >= 0 && temp_var <= 3){ cmd_byte |= temp_var << 1; } else{ return luaL_argerror( L, 1, "pwrdn: Valid range 0-3" ); } } else { return luaL_argerror( L, 1, "pwrdn: Must be number" ); } } lua_pop(L, 1); } uint8 *dac_value_byte = (uint8*) & dac_value; platform_i2c_send_start(mcp4725_i2c_id); platform_i2c_send_address(mcp4725_i2c_id, i2c_address, PLATFORM_I2C_DIRECTION_TRANSMITTER); platform_i2c_send_byte(mcp4725_i2c_id, cmd_byte); platform_i2c_send_byte(mcp4725_i2c_id, dac_value_byte[1]); platform_i2c_send_byte(mcp4725_i2c_id, dac_value_byte[0]); platform_i2c_send_stop(mcp4725_i2c_id); return 0; } static int mcp4725_read(lua_State* L){ uint8 i2c_address = MCP4725_I2C_ADDR_BASE; uint8 recieve_buffer[5] = {0}; if(lua_istable(L, 1)) { i2c_address = get_address(L, i2c_address); } platform_i2c_send_start(mcp4725_i2c_id); platform_i2c_send_address(mcp4725_i2c_id, i2c_address, PLATFORM_I2C_DIRECTION_RECEIVER); for(int i=0;i<5;i++){ recieve_buffer[i] = platform_i2c_recv_byte(mcp4725_i2c_id, 1); } platform_i2c_send_stop(mcp4725_i2c_id); lua_pushinteger(L, (recieve_buffer[0] & 0x06)>>1); lua_pushinteger(L, (recieve_buffer[1] << 4) | (recieve_buffer[2] >> 4)); lua_pushinteger(L, (recieve_buffer[3] & 0x60) >> 5); lua_pushinteger(L, ((recieve_buffer[3] & 0xf) << 8) | recieve_buffer[4]); lua_pushinteger(L, (recieve_buffer[0] & 0x80) >> 7); lua_pushinteger(L, (recieve_buffer[0] & 0x40) >> 6); return 6; } LROT_BEGIN(mcp4725, NULL, 0) LROT_FUNCENTRY( write, mcp4725_write ) LROT_FUNCENTRY( read, mcp4725_read ) LROT_NUMENTRY( PWRDN_NONE, MCP4725_POWER_DOWN_NORMAL ) LROT_NUMENTRY( PWRDN_1K, MCP4725_POWER_DOWN_RES_1K>>1 ) LROT_NUMENTRY( PWRDN_100K, MCP4725_POWER_DOWN_RES_100K>>1 ) LROT_NUMENTRY( PWRDN_500K, MCP4725_POWER_DOWN_RES_500K>>1 ) LROT_END(mcp4725, NULL, 0) NODEMCU_MODULE(MCP4725, "mcp4725", mcp4725, NULL);