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