[mlx90393] Fix inverted gain and resolution, change default values

The old gain options were copied from the arduino-MLX90393 library. However, the library actually does the opposite thing from the sensor hardware. Low hardware gain settings are multiplied with large numbers, while high gains are multiplied with small numbers. This is done in order to get consistent readings in µT independent of gain setting.

This is confusing from the user's perspective. The user configures the sensor, not the library.
Therefore, this PR inverts (actually 5/x) all gain settings. This reflects the analog gain used inside the sensor.

Furthermore, the resolution options are named more appropriately. The resolution is always 16 bit, we just choose which 16 bits we get.

Additionally, the default values are changed. The old defaults offered high sensitivity, but caused integer overflows in strong magnetic fields. This easily happened when a neodymium magnet was held within a few cm of the sensor.
The new default configuration prevents all integer overflows and can deal with strong fields easily.
Higher sensitivity must now be explicitly configured by the user. The new documentation informs about integer overflows, mitigating the risk of false readings that existed previously.

Finally, this commit exposes the already existing `hallconf` and `temperature_compensation` options.
This commit is contained in:
functionpointer 2024-10-19 17:48:15 +02:00
parent ef6ccddc0d
commit 6f16365b2f
11 changed files with 137 additions and 46 deletions

View file

@ -1,20 +1,20 @@
from esphome import pins
import esphome.codegen as cg
import esphome.config_validation as cv
from esphome.components import i2c, sensor
import esphome.config_validation as cv
from esphome.const import (
CONF_FILTER,
CONF_GAIN,
CONF_ID,
UNIT_MICROTESLA,
UNIT_CELSIUS,
STATE_CLASS_MEASUREMENT,
CONF_OVERSAMPLING,
CONF_RESOLUTION,
CONF_TEMPERATURE,
ICON_MAGNET,
ICON_THERMOMETER,
CONF_GAIN,
CONF_RESOLUTION,
CONF_OVERSAMPLING,
CONF_FILTER,
CONF_TEMPERATURE,
STATE_CLASS_MEASUREMENT,
UNIT_CELSIUS,
UNIT_MICROTESLA,
)
from esphome import pins
CODEOWNERS = ["@functionpointer"]
DEPENDENCIES = ["i2c"]
@ -26,30 +26,47 @@ MLX90393Component = mlx90393_ns.class_(
)
GAIN = {
"1X": 7,
"1_33X": 6,
"1_67X": 5,
"2X": 4,
"2_5X": 3,
"3X": 2,
"4X": 1,
"5X": 0,
"1X": 0,
"1_25X": 1,
"1_67X": 2,
"2X": 3,
"2_5X": 4,
"3X": 5,
"3_75X": 6,
"5X": 7,
}
RESOLUTION = {
"16BIT": 0,
"17BIT": 1,
"18BIT": 2,
"19BIT": 3,
"DIV_8": 3,
"DIV_4": 2,
"DIV_2": 1,
"DIV_1": 0,
}
CONF_X_AXIS = "x_axis"
CONF_Y_AXIS = "y_axis"
CONF_Z_AXIS = "z_axis"
CONF_DRDY_PIN = "drdy_pin"
CONF_TEMPERATURE_COMPENSATION = "temperature_compensation"
CONF_HALLCONF = "hallconf"
def mlx90393_axis_schema(default_resolution: str):
def _validate(config):
if config[CONF_TEMPERATURE_COMPENSATION]:
for axis in [CONF_X_AXIS, CONF_Y_AXIS, CONF_Z_AXIS]:
if axis not in config:
continue
if (res := config[axis][CONF_RESOLUTION]) in [
"DIV_8",
"DIV_4",
]:
raise cv.Invalid(
f"{axis}: {CONF_RESOLUTION} cannot be {res} with {CONF_TEMPERATURE_COMPENSATION} enabled"
)
return config
def mlx90393_axis_schema():
return sensor.sensor_schema(
unit_of_measurement=UNIT_MICROTESLA,
accuracy_decimals=0,
@ -58,7 +75,7 @@ def mlx90393_axis_schema(default_resolution: str):
).extend(
cv.Schema(
{
cv.Optional(CONF_RESOLUTION, default=default_resolution): cv.enum(
cv.Optional(CONF_RESOLUTION, default="DIV_8"): cv.enum(
RESOLUTION, upper=True, space="_"
)
}
@ -66,19 +83,19 @@ def mlx90393_axis_schema(default_resolution: str):
)
CONFIG_SCHEMA = (
CONFIG_SCHEMA = cv.All(
cv.Schema(
{
cv.GenerateID(): cv.declare_id(MLX90393Component),
cv.Optional(CONF_GAIN, default="2_5X"): cv.enum(
GAIN, upper=True, space="_"
),
cv.Optional(CONF_GAIN, default="1X"): cv.enum(GAIN, upper=True, space="_"),
cv.Optional(CONF_DRDY_PIN): pins.gpio_input_pin_schema,
cv.Optional(CONF_OVERSAMPLING, default=2): cv.int_range(min=0, max=3),
cv.Optional(CONF_OVERSAMPLING, default=0): cv.int_range(min=0, max=3),
cv.Optional(CONF_FILTER, default=6): cv.int_range(min=0, max=7),
cv.Optional(CONF_X_AXIS): mlx90393_axis_schema("19BIT"),
cv.Optional(CONF_Y_AXIS): mlx90393_axis_schema("19BIT"),
cv.Optional(CONF_Z_AXIS): mlx90393_axis_schema("16BIT"),
cv.Optional(CONF_X_AXIS): mlx90393_axis_schema(),
cv.Optional(CONF_Y_AXIS): mlx90393_axis_schema(),
cv.Optional(CONF_Z_AXIS): mlx90393_axis_schema(),
cv.Optional(CONF_TEMPERATURE_COMPENSATION, default=False): bool,
cv.Optional(CONF_HALLCONF, default=0xC): cv.one_of(0xC, 0x0),
cv.Optional(CONF_TEMPERATURE): sensor.sensor_schema(
unit_of_measurement=UNIT_CELSIUS,
accuracy_decimals=1,
@ -96,7 +113,8 @@ CONFIG_SCHEMA = (
},
)
.extend(cv.polling_component_schema("60s"))
.extend(i2c.i2c_device_schema(0x0C))
.extend(i2c.i2c_device_schema(0x0C)),
_validate,
)

View file

@ -43,6 +43,10 @@ void MLX90393Cls::setup() {
this->mlx_.setDigitalFiltering(this->filter_);
this->mlx_.setTemperatureOverSampling(this->temperature_oversampling_);
this->mlx_.setTemperatureCompensation(this->temperature_compensation_);
this->mlx_.setHallConf(this->hallconf_);
}
void MLX90393Cls::dump_config() {

View file

@ -29,7 +29,10 @@ class MLX90393Cls : public PollingComponent, public i2c::I2CDevice, public MLX90
void set_resolution(uint8_t xyz, uint8_t res) { resolutions_[xyz] = res; }
void set_filter(uint8_t filter) { filter_ = filter; }
void set_gain(uint8_t gain_sel) { gain_ = gain_sel; }
void set_temperature_compensation(bool temperature_compensation) {
temperature_compensation_ = temperature_compensation;
}
void set_hallconf(uint8_t hallconf) { hallconf_ = hallconf; }
// overrides for MLX library
// disable lint because it keeps suggesting const uint8_t *response.
@ -52,6 +55,8 @@ class MLX90393Cls : public PollingComponent, public i2c::I2CDevice, public MLX90
uint8_t temperature_oversampling_ = 0;
uint8_t filter_;
uint8_t resolutions_[3] = {0};
bool temperature_compensation_ = false;
uint8_t hallconf_ = 0xC;
GPIOPin *drdy_pin_{nullptr};
};

View file

@ -7,14 +7,17 @@ sensor:
- platform: mlx90393
oversampling: 1
filter: 0
gain: 3X
gain: 1X
temperature_compensation: true
x_axis:
name: mlxxaxis
resolution: DIV_2
y_axis:
name: mlxyaxis
resolution: DIV_1
z_axis:
name: mlxzaxis
resolution: 17BIT
resolution: DIV_2
temperature:
name: mlxtemp
oversampling: 2

View file

@ -7,14 +7,17 @@ sensor:
- platform: mlx90393
oversampling: 1
filter: 0
gain: 3X
gain: 1X
temperature_compensation: true
x_axis:
name: mlxxaxis
resolution: DIV_2
y_axis:
name: mlxyaxis
resolution: DIV_1
z_axis:
name: mlxzaxis
resolution: 17BIT
resolution: DIV_2
temperature:
name: mlxtemp
oversampling: 2

View file

@ -7,14 +7,17 @@ sensor:
- platform: mlx90393
oversampling: 1
filter: 0
gain: 3X
gain: 1X
temperature_compensation: true
x_axis:
name: mlxxaxis
resolution: DIV_2
y_axis:
name: mlxyaxis
resolution: DIV_1
z_axis:
name: mlxzaxis
resolution: 17BIT
resolution: DIV_2
temperature:
name: mlxtemp
oversampling: 2

View file

@ -7,14 +7,17 @@ sensor:
- platform: mlx90393
oversampling: 1
filter: 0
gain: 3X
gain: 1X
temperature_compensation: true
x_axis:
name: mlxxaxis
resolution: DIV_2
y_axis:
name: mlxyaxis
resolution: DIV_1
z_axis:
name: mlxzaxis
resolution: 17BIT
resolution: DIV_2
temperature:
name: mlxtemp
oversampling: 2

View file

@ -0,0 +1,23 @@
i2c:
- id: i2c_mlx90393
scl: 5
sda: 4
sensor:
- platform: mlx90393
oversampling: 1
filter: 0
gain: 1X
temperature_compensation: true
x_axis:
name: mlxxaxis
resolution: DIV_2
y_axis:
name: mlxyaxis
resolution: DIV_1
z_axis:
name: mlxzaxis
resolution: DIV_2
temperature:
name: mlxtemp
oversampling: 2

View file

@ -0,0 +1,23 @@
i2c:
- id: i2c_mlx90393
scl: 5
sda: 4
sensor:
- platform: mlx90393
oversampling: 1
filter: 0
gain: 1X
temperature_compensation: true
x_axis:
name: mlxxaxis
resolution: DIV_2
y_axis:
name: mlxyaxis
resolution: DIV_1
z_axis:
name: mlxzaxis
resolution: DIV_2
temperature:
name: mlxtemp
oversampling: 2

View file

@ -7,14 +7,17 @@ sensor:
- platform: mlx90393
oversampling: 1
filter: 0
gain: 3X
gain: 1X
temperature_compensation: true
x_axis:
name: mlxxaxis
resolution: DIV_2
y_axis:
name: mlxyaxis
resolution: DIV_1
z_axis:
name: mlxzaxis
resolution: 17BIT
resolution: DIV_2
temperature:
name: mlxtemp
oversampling: 2

View file

@ -7,14 +7,17 @@ sensor:
- platform: mlx90393
oversampling: 1
filter: 0
gain: 3X
gain: 1X
temperature_compensation: true
x_axis:
name: mlxxaxis
resolution: DIV_2
y_axis:
name: mlxyaxis
resolution: DIV_1
z_axis:
name: mlxzaxis
resolution: 17BIT
resolution: DIV_2
temperature:
name: mlxtemp
oversampling: 2