Add more getter functions to the commands module

examples/basic/main.rs

@@ -22,6 +22,11 @@ fn main() {
 
     let state = time::Instant::now();
     while state.elapsed() < time::Duration::from_secs(5) {
+        println!("");
+        println!(
+            "Coolant Temperature: {:?}",
+            device.get_engine_coolant_temperature()
+        );
         println!("RPM: {:?}", device.get_rpm());
         println!("Speed: {:?}", device.get_speed());
     }

src/commands/implementation.rs

@@ -1,6 +1,6 @@
-use crate::{commands::Obd2DataRetrieval, Error, Obd2Device, Result};
+use crate::{Error, Obd2Device, Result};
 
-use super::{Dtc, DtcsInfo};
+use super::{Dtc, DtcsInfo, Obd2DataRetrieval};
 
 impl<T: Obd2Device> Obd2DataRetrieval for T {
     fn get_vin(&mut self) -> Result<String> {
@@ -72,6 +72,22 @@ impl<T: Obd2Device> Obd2DataRetrieval for T {
             .collect::<Result<Vec<Vec<Dtc>>>>()
     }
 
+    fn get_engine_load(&mut self) -> Result<u8> {
+        Ok(self.obd_command_cnt_len::<1, 1>(0x01, 0x0C)?[0][0])
+    }
+
+    fn get_engine_coolant_temperature(&mut self) -> Result<i16> {
+        Ok((self.obd_command_cnt_len::<1, 1>(0x01, 0x0C)?[0][0] as i16) - 40)
+    }
+
+    fn get_fuel_pressure(&mut self) -> Result<i16> {
+        todo!()
+    }
+
+    fn get_engine_manifold_pressure(&mut self) -> Result<f32> {
+        todo!()
+    }
+
     fn get_rpm(&mut self) -> Result<f32> {
         let result = self.obd_command_cnt_len::<1, 2>(0x01, 0x0C)?[0];
         Ok(f32::from(u16::from_be_bytes(result)) / 4.0)

src/commands/mod.rs

@@ -16,8 +16,8 @@ pub trait Obd2DataRetrieval: private::Sealed {
 
     /// Retreive the VIN (vehicle identification number)
     ///
-    /// This should match the number printed on the vehicle, and is a good command for checking
-    /// that the OBD-II interface is working correctly.
+    /// Service 0x09, PID 0x01. This should match the number printed on the vehicle, and is a good
+    /// command for checking that the OBD-II interface is working correctly.
     fn get_vin(&mut self) -> Result<String>;
 
     /// Get DTC (diagnostic trouble code) metadata for each ECU
@@ -26,8 +26,21 @@ pub trait Obd2DataRetrieval: private::Sealed {
     /// Get DTCs for each ECU
     fn get_dtcs(&mut self) -> Result<Vec<Vec<Dtc>>>;
 
-    /// Get the calculated engine
-    // fn get_engine_load(&mut self) -> Result<u8>;
+    /// Get the calculated engine load (out of 255)
+    fn get_engine_load(&mut self) -> Result<u8>;
+
+    /// Get the temperature of the engine's coolant in ºC
+    fn get_engine_coolant_temperature(&mut self) -> Result<i16>;
+
+    /// Get the fuel pressure in kPa
+    ///
+    /// This measurement is gauge pressure (measured relative to the atmosphere)
+    fn get_fuel_pressure(&mut self) -> Result<i16>;
+
+    /// Get the intake manifold pressure in kPa
+    ///
+    /// This measurement is absolute pressure.
+    fn get_engine_manifold_pressure(&mut self) -> Result<f32>;
 
     /// Get the RPM in increments of 0.25
     fn get_rpm(&mut self) -> Result<f32>;

src/lib.rs

@@ -1,5 +1,7 @@
 //! Crate for communicating with OBD-II (on-board diagnostics) interfaces on cars
 //!
+//! The high-level data retrieval functions can be found in [commands::Obd2DataRetrieval].
+//!
 //! # Usage
 //! ```
 //! use obd2::{commands::Obd2DataRetrieval, device::Elm327, Obd2};