drivers: sensor: max31865: fix compilation warning -Wdouble-promotion

Fixes type mix-match for rtd temperature calculation. Also changes
coefficient array name for clarity.

Signed-off-by: Maxmillion McLaughlin <max@sorcerer.earth>
This commit is contained in:
Maxmillion McLaughlin 2024-12-03 17:19:50 -08:00 committed by Benjamin Cabé
commit 7497b8bbbe
2 changed files with 4 additions and 4 deletions

View file

@ -99,9 +99,9 @@ static double calculate_temperature(double resistance, double resistance_0)
}
resistance /= resistance_0;
resistance *= 100.0;
temperature = A[0] + A[1] * resistance + A[2] * pow(resistance, 2) -
A[3] * pow(resistance, 3) - A[4] * pow(resistance, 4) +
A[5] * pow(resistance, 5);
temperature = RTD_C[0] + RTD_C[1] * resistance + RTD_C[2] * pow(resistance, 2) -
RTD_C[3] * pow(resistance, 3) - RTD_C[4] * pow(resistance, 4) +
RTD_C[5] * pow(resistance, 5);
return temperature;
}

View file

@ -71,7 +71,7 @@ LOG_MODULE_REGISTER(MAX31865, CONFIG_SENSOR_LOG_LEVEL);
* For under zero, taken from
* https://www.analog.com/media/en/technical-documentation/application-notes/AN709_0.pdf
*/
static const float A[6] = {-242.02, 2.2228, 2.5859e-3, 4.8260e-6, 2.8183e-8, 1.5243e-10};
static const double RTD_C[6] = {-242.02, 2.2228, 2.5859e-3, 4.8260e-6, 2.8183e-8, 1.5243e-10};
struct max31865_data {
double temperature;