Initial proof of concept

src/transducer/part/thermistor.rs

@@ -0,0 +1,38 @@
+use crate::quantity::{Kelvins, Ohms};
+use libm::{log, logf};
+
+/// Convert thermistor resistance to a temperature using beta parameter equation
+pub fn convert_beta(
+    resistance: Ohms<f32>,
+    beta: f32,
+    reference_temp: Kelvins<f32>,
+    reference_resist: Ohms<f32>,
+) -> Kelvins<f32> {
+    let kelvins = 1.0 / ((logf(resistance.0 / reference_resist.0) / beta) + 1.0 / reference_temp.0);
+    Kelvins(kelvins)
+}
+
+/// Convert thermistor resistance to a temperature using Steinhart-Hart equation
+pub fn convert_steinhart(resistance: Ohms<f64>, a: f64, b: f64, c: f64) -> Kelvins<f32> {
+    let log_omhs = log(resistance.0);
+    let kelvins = 1.0 / (a + b * log_omhs + c * log_omhs * log_omhs * log_omhs);
+    Kelvins(kelvins as f32)
+}
+
+// ---------------------------------------------------------------------------------------------------------------------
+// ----- Tests ------------------------
+// ---------------------------------------------------------------------------------------------------------------------
+#[cfg(test)]
+mod tests {
+    use float_cmp::assert_approx_eq;
+
+    use crate::quantity::{OhmsVal, KelvinsVal};
+    use super::*;
+
+    #[test]
+    fn convert_beta_test() {
+        let temperature = convert_beta(1538.462.ohms(), 3950.0, 298.15.kelvins(), 100_000.0.ohms());
+
+        assert_approx_eq!(f32, 435.31073, temperature.0);
+    }
+}