nodemcu-firmware/app/modules/ads1115.c

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//***************************************************************************
// Si7021 module for ESP8266 with nodeMCU
// fetchbot @github
// MIT license, http://opensource.org/licenses/MIT
//***************************************************************************
#include "module.h"
#include "lauxlib.h"
#include "platform.h"
#include "osapi.h"
//***************************************************************************
// I2C ADDRESS DEFINITON
//***************************************************************************
#define ADS1115_I2C_ADDR_GND (0x48)
#define ADS1115_I2C_ADDR_VDD (0x49)
#define ADS1115_I2C_ADDR_SDA (0x4A)
#define ADS1115_I2C_ADDR_SCL (0x4B)
//***************************************************************************
// POINTER REGISTER
//***************************************************************************
#define ADS1115_POINTER_MASK (0x03)
#define ADS1115_POINTER_CONVERSION (0x00)
#define ADS1115_POINTER_CONFIG (0x01)
#define ADS1115_POINTER_THRESH_LOW (0x02)
#define ADS1115_POINTER_THRESH_HI (0x03)
//***************************************************************************
// CONFIG REGISTER
//***************************************************************************
#define ADS1115_OS_MASK (0x8000)
#define ADS1115_OS_NON (0x0000)
#define ADS1115_OS_SINGLE (0x8000) // Write: Set to start a single-conversion
#define ADS1115_OS_BUSY (0x0000) // Read: Bit = 0 when conversion is in progress
#define ADS1115_OS_NOTBUSY (0x8000) // Read: Bit = 1 when device is not performing a conversion
#define ADS1115_MUX_MASK (0x7000)
#define ADS1115_MUX_DIFF_0_1 (0x0000) // Differential P = AIN0, N = AIN1 (default)
#define ADS1115_MUX_DIFF_0_3 (0x1000) // Differential P = AIN0, N = AIN3
#define ADS1115_MUX_DIFF_1_3 (0x2000) // Differential P = AIN1, N = AIN3
#define ADS1115_MUX_DIFF_2_3 (0x3000) // Differential P = AIN2, N = AIN3
#define ADS1115_MUX_SINGLE_0 (0x4000) // Single-ended AIN0
#define ADS1115_MUX_SINGLE_1 (0x5000) // Single-ended AIN1
#define ADS1115_MUX_SINGLE_2 (0x6000) // Single-ended AIN2
#define ADS1115_MUX_SINGLE_3 (0x7000) // Single-ended AIN3
#define ADS1115_PGA_MASK (0x0E00)
#define ADS1115_PGA_6_144V (0x0000) // +/-6.144V range = Gain 2/3
#define ADS1115_PGA_4_096V (0x0200) // +/-4.096V range = Gain 1
#define ADS1115_PGA_2_048V (0x0400) // +/-2.048V range = Gain 2 (default)
#define ADS1115_PGA_1_024V (0x0600) // +/-1.024V range = Gain 4
#define ADS1115_PGA_0_512V (0x0800) // +/-0.512V range = Gain 8
#define ADS1115_PGA_0_256V (0x0A00) // +/-0.256V range = Gain 16
#define ADS1115_MODE_MASK (0x0100)
#define ADS1115_MODE_CONTIN (0x0000) // Continuous conversion mode
#define ADS1115_MODE_SINGLE (0x0100) // Power-down single-shot mode (default)
#define ADS1115_DR_MASK (0x00E0)
#define ADS1115_DR_8SPS (0x0000) // 8 samples per second
#define ADS1115_DR_16SPS (0x0020) // 16 samples per second
#define ADS1115_DR_32SPS (0x0040) // 32 samples per second
#define ADS1115_DR_64SPS (0x0060) // 64 samples per second
#define ADS1115_DR_128SPS (0x0080) // 128 samples per second (default)
#define ADS1115_DR_250SPS (0x00A0) // 250 samples per second
#define ADS1115_DR_475SPS (0x00C0) // 475 samples per second
#define ADS1115_DR_860SPS (0x00E0) // 860 samples per second
#define ADS1115_CMODE_MASK (0x0010)
#define ADS1115_CMODE_TRAD (0x0000) // Traditional comparator with hysteresis (default)
#define ADS1115_CMODE_WINDOW (0x0010) // Window comparator
#define ADS1115_CPOL_MASK (0x0008)
#define ADS1115_CPOL_ACTVLOW (0x0000) // ALERT/RDY pin is low when active (default)
#define ADS1115_CPOL_ACTVHI (0x0008) // ALERT/RDY pin is high when active
#define ADS1115_CLAT_MASK (0x0004) // Determines if ALERT/RDY pin latches once asserted
#define ADS1115_CLAT_NONLAT (0x0000) // Non-latching comparator (default)
#define ADS1115_CLAT_LATCH (0x0004) // Latching comparator
#define ADS1115_CQUE_MASK (0x0003)
#define ADS1115_CQUE_1CONV (0x0000) // Assert ALERT/RDY after one conversions
#define ADS1115_CQUE_2CONV (0x0001) // Assert ALERT/RDY after two conversions
#define ADS1115_CQUE_4CONV (0x0002) // Assert ALERT/RDY after four conversions
#define ADS1115_CQUE_NONE (0x0003) // Disable the comparator and put ALERT/RDY in high state (default)
//***************************************************************************
static const uint8_t ads1115_i2c_id = 0;
static const uint8_t general_i2c_addr = 0x00;
static const uint8_t ads1115_i2c_reset = 0x06;
static uint8_t ads1115_i2c_addr = ADS1115_I2C_ADDR_GND;
static uint16_t ads1115_os = ADS1115_OS_SINGLE;
static uint16_t ads1115_gain = ADS1115_PGA_6_144V;
static uint16_t ads1115_samples = ADS1115_DR_128SPS;
static uint16_t ads1115_channel = ADS1115_MUX_SINGLE_0;
static uint16_t ads1115_comp = ADS1115_CQUE_NONE;
static uint16_t ads1115_mode = ADS1115_MODE_SINGLE;
static uint16_t ads1115_threshold_low = 0x8000;
static uint16_t ads1115_threshold_hi = 0x7FFF;
static uint16_t ads1115_config = 0x8583;
static uint16_t ads1115_conversion = 0;
static double ads1115_volt = 0;
os_timer_t ads1115_timer; // timer for conversion delay
int ads1115_timer_ref; // callback when readout is ready
static int ads1115_lua_readoutdone(void);
static uint8_t write_reg(uint8_t reg, uint16_t config) {
platform_i2c_send_start(ads1115_i2c_id);
platform_i2c_send_address(ads1115_i2c_id, ads1115_i2c_addr, PLATFORM_I2C_DIRECTION_TRANSMITTER);
platform_i2c_send_byte(ads1115_i2c_id, reg);
platform_i2c_send_byte(ads1115_i2c_id, (uint8_t)(config >> 8));
platform_i2c_send_byte(ads1115_i2c_id, (uint8_t)(config & 0xFF));
platform_i2c_send_stop(ads1115_i2c_id);
}
static uint16_t read_reg(uint8_t reg) {
platform_i2c_send_start(ads1115_i2c_id);
platform_i2c_send_address(ads1115_i2c_id, ads1115_i2c_addr, PLATFORM_I2C_DIRECTION_TRANSMITTER);
platform_i2c_send_byte(ads1115_i2c_id, reg);
platform_i2c_send_stop(ads1115_i2c_id);
platform_i2c_send_start(ads1115_i2c_id);
platform_i2c_send_address(ads1115_i2c_id, ads1115_i2c_addr, PLATFORM_I2C_DIRECTION_RECEIVER);
uint16_t buf = (platform_i2c_recv_byte(ads1115_i2c_id, 1) << 8);
buf += platform_i2c_recv_byte(ads1115_i2c_id, 0);
platform_i2c_send_stop(ads1115_i2c_id);
return buf;
}
// convert ADC value to voltage corresponding to PGA settings
static double get_volt(uint16_t value) {
double volt = 0;
switch (ads1115_gain) {
case (ADS1115_PGA_6_144V):
volt = (int16_t)value * 0.1875;
break;
case (ADS1115_PGA_4_096V):
volt = (int16_t)value * 0.125;
break;
case (ADS1115_PGA_2_048V):
volt = (int16_t)value * 0.0625;
break;
case (ADS1115_PGA_1_024V):
volt = (int16_t)value * 0.03125;
break;
case (ADS1115_PGA_0_512V):
volt = (int16_t)value * 0.015625;
break;
case (ADS1115_PGA_0_256V):
volt = (int16_t)value * 0.0078125;
break;
}
return volt;
}
// convert threshold in volt to ADC value corresponding to PGA settings
static uint8_t get_value(int16_t *volt) {
switch (ads1115_gain) {
case (ADS1115_PGA_6_144V):
if ((*volt >= 6144) || (*volt < -6144) || ((*volt < 0) && (ads1115_channel >> 14))) return 1;
*volt = *volt / 0.1875;
break;
case (ADS1115_PGA_4_096V):
if ((*volt >= 4096) || (*volt < -4096) || ((*volt < 0) && (ads1115_channel >> 14))) return 1;
*volt = *volt / 0.125;
break;
case (ADS1115_PGA_2_048V):
if ((*volt >= 2048) || (*volt < -2048) || ((*volt < 0) && (ads1115_channel >> 14))) return 1;
*volt = *volt / 0.0625;
break;
case (ADS1115_PGA_1_024V):
if ((*volt >= 1024) || (*volt < -1024) || ((*volt < 0) && (ads1115_channel >> 14))) return 1;
*volt = *volt / 0.03125;
break;
case (ADS1115_PGA_0_512V):
if ((*volt >= 512) || (*volt < -512) || ((*volt < 0) && (ads1115_channel >> 14))) return 1;
*volt = *volt / 0.015625;
break;
case (ADS1115_PGA_0_256V):
if ((*volt >= 256) || (*volt < -256) || ((*volt < 0) && (ads1115_channel >> 14))) return 1;
*volt = *volt / 0.0078125;
break;
}
return 0;
}
// Initializes ADC
// Lua: ads11115.setup(ADDRESS)
static int ads1115_lua_setup(lua_State *L) {
// check variables
if (!lua_isnumber(L, 1)) {
return luaL_error(L, "wrong arg range");
}
ads1115_i2c_addr = luaL_checkinteger(L, 1);
if (!((ads1115_i2c_addr == ADS1115_I2C_ADDR_GND) || (ads1115_i2c_addr == ADS1115_I2C_ADDR_VDD) || (ads1115_i2c_addr == ADS1115_I2C_ADDR_SDA) || (ads1115_i2c_addr == ADS1115_I2C_ADDR_SCL))) {
return luaL_error(L, "Invalid argument: adddress");
}
platform_i2c_send_start(ads1115_i2c_id);
platform_i2c_send_address(ads1115_i2c_id, general_i2c_addr, PLATFORM_I2C_DIRECTION_TRANSMITTER);
platform_i2c_send_byte(ads1115_i2c_id, ads1115_i2c_reset);
platform_i2c_send_stop(ads1115_i2c_id);
// check for device on i2c bus
if (read_reg(ADS1115_POINTER_CONFIG) != 0x8583) {
return luaL_error(L, "found no device");
}
return 0;
}
// Change ADC settings
// Lua: ads1115.setting(GAIN,SAMPLES,CHANNEL,MODE[,CONVERSION_RDY][,COMPARATOR,THRESHOLD_LOW,THRESHOLD_HI])
static int ads1115_lua_setting(lua_State *L) {
// check variables
if (!lua_isnumber(L, 1) || !lua_isnumber(L, 2) || !lua_isnumber(L, 3) || !lua_isnumber(L, 4)) {
return luaL_error(L, "wrong arg range");
}
ads1115_gain = luaL_checkinteger(L, 1);
if (!((ads1115_gain == ADS1115_PGA_6_144V) || (ads1115_gain == ADS1115_PGA_4_096V) || (ads1115_gain == ADS1115_PGA_2_048V) || (ads1115_gain == ADS1115_PGA_1_024V) || (ads1115_gain == ADS1115_PGA_0_512V) || (ads1115_gain == ADS1115_PGA_0_256V))) {
return luaL_error(L, "Invalid argument: gain");
}
ads1115_samples = luaL_checkinteger(L, 2);
if (!((ads1115_samples == ADS1115_DR_8SPS) || (ads1115_samples == ADS1115_DR_16SPS) || (ads1115_samples == ADS1115_DR_32SPS) || (ads1115_samples == ADS1115_DR_64SPS) || (ads1115_samples == ADS1115_DR_128SPS) || (ads1115_samples == ADS1115_DR_250SPS) || (ads1115_samples == ADS1115_DR_475SPS) || (ads1115_samples == ADS1115_DR_860SPS))) {
return luaL_error(L, "Invalid argument: samples");
}
ads1115_channel = luaL_checkinteger(L, 3);
if (!((ads1115_channel == ADS1115_MUX_SINGLE_0) || (ads1115_channel == ADS1115_MUX_SINGLE_1) || (ads1115_channel == ADS1115_MUX_SINGLE_2) || (ads1115_channel == ADS1115_MUX_SINGLE_3) || (ads1115_channel == ADS1115_MUX_DIFF_0_1) || (ads1115_channel == ADS1115_MUX_DIFF_0_3) || (ads1115_channel == ADS1115_MUX_DIFF_1_3) || (ads1115_channel == ADS1115_MUX_DIFF_2_3))) {
return luaL_error(L, "Invalid argument: channel");
}
ads1115_mode = luaL_checkinteger(L, 4);
if (!((ads1115_mode == ADS1115_MODE_SINGLE) || (ads1115_mode == ADS1115_MODE_CONTIN))) {
return luaL_error(L, "Invalid argument: mode");
}
if (ads1115_mode == ADS1115_MODE_SINGLE) {
ads1115_os = ADS1115_OS_SINGLE;
} else {
ads1115_os = ADS1115_OS_NON;
}
ads1115_comp = ADS1115_CQUE_NONE;
// Parse optional parameters
if (lua_isnumber(L, 5) && !(lua_isnumber(L, 6) || lua_isnumber(L, 7))) {
// conversion ready mode
ads1115_comp = luaL_checkinteger(L, 5);
if (!((ads1115_comp == ADS1115_CQUE_1CONV) || (ads1115_comp == ADS1115_CQUE_2CONV) || (ads1115_comp == ADS1115_CQUE_4CONV))) {
return luaL_error(L, "Invalid argument: conversion ready mode");
}
ads1115_threshold_low = 0x7FFF;
ads1115_threshold_hi = 0x8000;
write_reg(ADS1115_POINTER_THRESH_LOW, ads1115_threshold_low);
write_reg(ADS1115_POINTER_THRESH_HI, ads1115_threshold_hi);
} else if (lua_isnumber(L, 5) && lua_isnumber(L, 6) && lua_isnumber(L, 7)) {
// comparator mode
ads1115_comp = luaL_checkinteger(L, 5);
if (!((ads1115_comp == ADS1115_CQUE_1CONV) || (ads1115_comp == ADS1115_CQUE_2CONV) || (ads1115_comp == ADS1115_CQUE_4CONV))) {
return luaL_error(L, "Invalid argument: comparator mode");
}
ads1115_threshold_low = luaL_checkinteger(L, 5);
ads1115_threshold_hi = luaL_checkinteger(L, 6);
if ((int16_t)ads1115_threshold_low > (int16_t)ads1115_threshold_hi) {
return luaL_error(L, "Invalid argument: threshold_low > threshold_hi");
}
if (get_value(&ads1115_threshold_low)) {
return luaL_error(L, "Invalid argument: threshold_low");
}
if (get_value(&ads1115_threshold_hi)) {
return luaL_error(L, "Invalid argument: threshold_hi");
}
write_reg(ADS1115_POINTER_THRESH_LOW, ads1115_threshold_low);
write_reg(ADS1115_POINTER_THRESH_HI, ads1115_threshold_hi);
}
ads1115_config = (ads1115_os | ads1115_channel | ads1115_gain | ads1115_mode | ads1115_samples | ADS1115_CMODE_TRAD | ADS1115_CPOL_ACTVLOW | ADS1115_CLAT_NONLAT | ads1115_comp);
write_reg(ADS1115_POINTER_CONFIG, ads1115_config);
return 0;
}
// Read the conversion register from the ADC
// Lua: ads1115.startread(function(volt, voltdec, adc) print(volt,voltdec,adc) end)
static int ads1115_lua_startread(lua_State *L) {
if (((ads1115_comp == ADS1115_CQUE_1CONV) || (ads1115_comp == ADS1115_CQUE_2CONV) || (ads1115_comp == ADS1115_CQUE_4CONV)) && (ads1115_threshold_low == 0x7FFF) && (ads1115_threshold_hi == 0x8000)) {
if (ads1115_mode == ADS1115_MODE_SINGLE) {
write_reg(ADS1115_POINTER_CONFIG, ads1115_config);
}
return 0;
} else {
luaL_argcheck(L, (lua_type(L, 1) == LUA_TFUNCTION || lua_type(L, 1) == LUA_TLIGHTFUNCTION), 1, "Must be function");
lua_pushvalue(L, 1);
ads1115_timer_ref = luaL_ref(L, LUA_REGISTRYINDEX);
if (ads1115_mode == ADS1115_MODE_SINGLE) {
write_reg(ADS1115_POINTER_CONFIG, ads1115_config);
}
// Start a timer to wait until ADC conversion is done
os_timer_disarm (&ads1115_timer);
os_timer_setfn (&ads1115_timer, (os_timer_func_t *)ads1115_lua_readoutdone, NULL);
switch (ads1115_samples) {
case (ADS1115_DR_8SPS):
os_timer_arm (&ads1115_timer, 150, 0);
break;
case (ADS1115_DR_16SPS):
os_timer_arm (&ads1115_timer, 75, 0);
break;
case (ADS1115_DR_32SPS):
os_timer_arm (&ads1115_timer, 35, 0);
break;
case (ADS1115_DR_64SPS):
os_timer_arm (&ads1115_timer, 20, 0);
break;
case (ADS1115_DR_128SPS):
os_timer_arm (&ads1115_timer, 10, 0);
break;
case (ADS1115_DR_250SPS):
os_timer_arm (&ads1115_timer, 5, 0);
break;
case (ADS1115_DR_475SPS):
os_timer_arm (&ads1115_timer, 3, 0);
break;
case (ADS1115_DR_860SPS):
os_timer_arm (&ads1115_timer, 2, 0);
break;
}
return 0;
}
}
// adc conversion timer callback
static int ads1115_lua_readoutdone(void) {
ads1115_conversion = read_reg(ADS1115_POINTER_CONVERSION);
ads1115_volt = get_volt(ads1115_conversion);
int ads1115_voltdec = (int)((ads1115_volt - (int)ads1115_volt) * 1000);
ads1115_voltdec = ads1115_voltdec>0?ads1115_voltdec:0-ads1115_voltdec;
lua_State *L = lua_getstate();
os_timer_disarm (&ads1115_timer);
lua_rawgeti (L, LUA_REGISTRYINDEX, ads1115_timer_ref);
luaL_unref (L, LUA_REGISTRYINDEX, ads1115_timer_ref);
ads1115_timer_ref = LUA_NOREF;
lua_pushnumber(L, ads1115_volt);
lua_pushinteger(L, ads1115_voltdec);
lua_pushinteger(L, ads1115_conversion);
lua_call (L, 3, 0);
}
// Read the conversion register from the ADC
// Lua: volt,voltdec,adc = ads1115.read()
static int ads1115_lua_read(lua_State *L) {
ads1115_conversion = read_reg(ADS1115_POINTER_CONVERSION);
ads1115_volt = get_volt(ads1115_conversion);
int ads1115_voltdec = (int)((ads1115_volt - (int)ads1115_volt) * 1000);
ads1115_voltdec = ads1115_voltdec>0?ads1115_voltdec:0-ads1115_voltdec;
lua_pushnumber(L, ads1115_volt);
lua_pushinteger(L, ads1115_voltdec);
lua_pushinteger(L, ads1115_conversion);
return 3;
}
static const LUA_REG_TYPE ads1115_map[] = {
{ LSTRKEY( "setup" ), LFUNCVAL(ads1115_lua_setup) },
{ LSTRKEY( "setting" ), LFUNCVAL(ads1115_lua_setting) },
{ LSTRKEY( "startread" ), LFUNCVAL(ads1115_lua_startread) },
{ LSTRKEY( "read" ), LFUNCVAL(ads1115_lua_read) },
{ LSTRKEY( "ADDR_GND" ), LNUMVAL(ADS1115_I2C_ADDR_GND) },
{ LSTRKEY( "ADDR_VDD" ), LNUMVAL(ADS1115_I2C_ADDR_VDD) },
{ LSTRKEY( "ADDR_SDA" ), LNUMVAL(ADS1115_I2C_ADDR_SDA) },
{ LSTRKEY( "ADDR_SCL" ), LNUMVAL(ADS1115_I2C_ADDR_SCL) },
{ LSTRKEY( "SINGLE_SHOT" ), LNUMVAL(ADS1115_MODE_SINGLE) },
{ LSTRKEY( "CONTINUOUS" ), LNUMVAL(ADS1115_MODE_CONTIN) },
{ LSTRKEY( "DIFF_0_1" ), LNUMVAL(ADS1115_MUX_DIFF_0_1) },
{ LSTRKEY( "DIFF_0_3" ), LNUMVAL(ADS1115_MUX_DIFF_0_3) },
{ LSTRKEY( "DIFF_1_3" ), LNUMVAL(ADS1115_MUX_DIFF_1_3) },
{ LSTRKEY( "DIFF_2_3" ), LNUMVAL(ADS1115_MUX_DIFF_2_3) },
{ LSTRKEY( "SINGLE_0" ), LNUMVAL(ADS1115_MUX_SINGLE_0) },
{ LSTRKEY( "SINGLE_1" ), LNUMVAL(ADS1115_MUX_SINGLE_1) },
{ LSTRKEY( "SINGLE_2" ), LNUMVAL(ADS1115_MUX_SINGLE_2) },
{ LSTRKEY( "SINGLE_3" ), LNUMVAL(ADS1115_MUX_SINGLE_3) },
{ LSTRKEY( "GAIN_6_144V" ), LNUMVAL(ADS1115_PGA_6_144V) },
{ LSTRKEY( "GAIN_4_096V" ), LNUMVAL(ADS1115_PGA_4_096V) },
{ LSTRKEY( "GAIN_2_048V" ), LNUMVAL(ADS1115_PGA_2_048V) },
{ LSTRKEY( "GAIN_1_024V" ), LNUMVAL(ADS1115_PGA_1_024V) },
{ LSTRKEY( "GAIN_0_512V" ), LNUMVAL(ADS1115_PGA_0_512V) },
{ LSTRKEY( "GAIN_0_256V" ), LNUMVAL(ADS1115_PGA_0_256V) },
{ LSTRKEY( "DR_8SPS" ), LNUMVAL(ADS1115_DR_8SPS) },
{ LSTRKEY( "DR_16SPS" ), LNUMVAL(ADS1115_DR_16SPS) },
{ LSTRKEY( "DR_32SPS" ), LNUMVAL(ADS1115_DR_32SPS) },
{ LSTRKEY( "DR_64SPS" ), LNUMVAL(ADS1115_DR_64SPS) },
{ LSTRKEY( "DR_128SPS" ), LNUMVAL(ADS1115_DR_128SPS) },
{ LSTRKEY( "DR_250SPS" ), LNUMVAL(ADS1115_DR_250SPS) },
{ LSTRKEY( "DR_475SPS" ), LNUMVAL(ADS1115_DR_475SPS) },
{ LSTRKEY( "DR_860SPS" ), LNUMVAL(ADS1115_DR_860SPS) },
{ LSTRKEY( "CONV_RDY_1" ), LNUMVAL(ADS1115_CQUE_1CONV) },
{ LSTRKEY( "CONV_RDY_2" ), LNUMVAL(ADS1115_CQUE_2CONV) },
{ LSTRKEY( "CONV_RDY_4" ), LNUMVAL(ADS1115_CQUE_4CONV) },
{ LSTRKEY( "COMP_1CONV" ), LNUMVAL(ADS1115_CQUE_1CONV) },
{ LSTRKEY( "COMP_2CONV" ), LNUMVAL(ADS1115_CQUE_2CONV) },
{ LSTRKEY( "COMP_4CONV" ), LNUMVAL(ADS1115_CQUE_4CONV) },
{ LNILKEY, LNILVAL }
};
NODEMCU_MODULE(ADS1115, "ads1115", ads1115_map, NULL);