esphome/esphome/components/ads1118/ads1118.cpp
Solomon c52052563f
ads1118 component (#5711)
Co-authored-by: Solomon <solomon.gorkhover@finnpartners.com>
Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
2024-03-11 11:09:05 +13:00

126 lines
3.2 KiB
C++

#include "ads1118.h"
#include "esphome/core/log.h"
namespace esphome {
namespace ads1118 {
static const char *const TAG = "ads1118";
static const uint8_t ADS1118_DATA_RATE_860_SPS = 0b111;
void ADS1118::setup() {
ESP_LOGCONFIG(TAG, "Setting up ads1118");
this->spi_setup();
this->config_ = 0;
// Setup multiplexer
// 0bx000xxxxxxxxxxxx
this->config_ |= ADS1118_MULTIPLEXER_P0_NG << 12;
// Setup Gain
// 0bxxxx000xxxxxxxxx
this->config_ |= ADS1118_GAIN_6P144 << 9;
// Set singleshot mode
// 0bxxxxxxx1xxxxxxxx
this->config_ |= 0b0000000100000000;
// Set data rate - 860 samples per second (we're in singleshot mode)
// 0bxxxxxxxx100xxxxx
this->config_ |= ADS1118_DATA_RATE_860_SPS << 5;
// Set temperature sensor mode - ADC
// 0bxxxxxxxxxxx0xxxx
this->config_ |= 0b0000000000000000;
// Set DOUT pull up - enable
// 0bxxxxxxxxxxxx0xxx
this->config_ |= 0b0000000000001000;
// NOP - must be 01
// 0bxxxxxxxxxxxxx01x
this->config_ |= 0b0000000000000010;
// Not used - can be 0 or 1, lets be positive
// 0bxxxxxxxxxxxxxxx1
this->config_ |= 0b0000000000000001;
}
void ADS1118::dump_config() {
ESP_LOGCONFIG(TAG, "ADS1118:");
LOG_PIN(" CS Pin:", this->cs_);
}
float ADS1118::request_measurement(ADS1118Multiplexer multiplexer, ADS1118Gain gain, bool temperature_mode) {
uint16_t temp_config = this->config_;
// Multiplexer
// 0bxBBBxxxxxxxxxxxx
temp_config &= 0b1000111111111111;
temp_config |= (multiplexer & 0b111) << 12;
// Gain
// 0bxxxxBBBxxxxxxxxx
temp_config &= 0b1111000111111111;
temp_config |= (gain & 0b111) << 9;
if (temperature_mode) {
// Set temperature sensor mode
// 0bxxxxxxxxxxx1xxxx
temp_config |= 0b0000000000010000;
} else {
// Set ADC mode
// 0bxxxxxxxxxxx0xxxx
temp_config &= 0b1111111111101111;
}
// Start conversion
temp_config |= 0b1000000000000000;
this->enable();
this->write_byte16(temp_config);
this->disable();
// about 1.2 ms with 860 samples per second
delay(2);
this->enable();
uint8_t adc_first_byte = this->read_byte();
uint8_t adc_second_byte = this->read_byte();
this->disable();
uint16_t raw_conversion = encode_uint16(adc_first_byte, adc_second_byte);
auto signed_conversion = static_cast<int16_t>(raw_conversion);
if (temperature_mode) {
return (signed_conversion >> 2) * 0.03125f;
} else {
float millivolts;
float divider = 32768.0f;
switch (gain) {
case ADS1118_GAIN_6P144:
millivolts = (signed_conversion * 6144) / divider;
break;
case ADS1118_GAIN_4P096:
millivolts = (signed_conversion * 4096) / divider;
break;
case ADS1118_GAIN_2P048:
millivolts = (signed_conversion * 2048) / divider;
break;
case ADS1118_GAIN_1P024:
millivolts = (signed_conversion * 1024) / divider;
break;
case ADS1118_GAIN_0P512:
millivolts = (signed_conversion * 512) / divider;
break;
case ADS1118_GAIN_0P256:
millivolts = (signed_conversion * 256) / divider;
break;
default:
millivolts = NAN;
}
return millivolts / 1e3f;
}
}
} // namespace ads1118
} // namespace esphome