remove defmt dependency & feature

based on the discussion on GitHub we don't need this dependency. it's
the only 0.x dependency currently present in the crate and doesn't
provide a lot of value since consuming code can use
`defmt::Debug2Format` when needed. the single `defmt::debug!` statement
in `Motor::drive` was not very helpful anyway if two motors were
connected as it did not differentiate between the motors in the message.

since this was the only optional feature there's no need anymore to test
with `--all-features` in the CI. this has been removed from the build
matrix (but the possibility to add it later has been kept as it doesn't
make the build script unnecessarily complicated).

Author: rursprung

.github/workflows/CI.yml

@@ -14,10 +14,7 @@ jobs:
       fail-fast: false
       matrix:
         rust: [1.63.0, stable]
-        features: ['', '--all-features']
-        exclude:
-          - rust: 1.63.0
-            features: '--all-features'
+        features: ['']
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4

CHANGELOG.md

@@ -26,6 +26,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Removed the `drive_forward`, `drive_backward`, `stop` and `brake`
   functions as they are duplicates to the `drive` function with the
   different enum variants and make the API surface larger
+* Removed the `defmt` feature: it was only used for debugging and since the `enum`s & `struct`s implement `Debug`
+  consuming code can use `defmt::Debug2Format` when needed. The single `defmt::debug!` statement in `Motor::drive` was
+  not very helpful anyway if two motors were connected
 
 ## [0.2.0] - 2023-11-28
 

Cargo.toml

@@ -12,7 +12,6 @@ license = "MIT OR Apache-2.0"
 authors = ["Ralph Ursprung <[email protected]>", "ripytide <[email protected]>"]
 
 [features]
-defmt-03 = ["dep:defmt"]
 
 [dependencies]
 embedded-hal = "1.0"

README.md

@@ -20,9 +20,6 @@ See the documentation for usage examples.
 * You plan on using a single motor with the standby feature: use `Motor` and control the standby pin manually
 * You plan on using a single motor without the standby feature: use `Motor`
 
-## Optional features
-* `defmt-03`: you can enable this feature to get a `defmt::Format` implementation for all structs & enums in this crate and a `defmt::debug` call for every speed change.
-
 ## Examples
 A simple example for the STM32F4 microcontrollers is [available](examples/stm32f4-single-motor-example/README.md).
 

src/lib.rs

@@ -9,9 +9,6 @@
 //! * You plan on using both motors without the standby feature: use two separate [`Motor`]s
 //! * You plan on using a single motor with the standby feature: use [`Motor`] and control the standby pin manually
 //! * You plan on using a single motor without the standby feature: use [`Motor`]
-//!
-//! ## Optional features
-//! * `defmt-03`: you can enable this feature to get a `defmt::Format` implementation for all structs & enums in this crate and a `defmt::debug` call for every speed change.
 
 #![forbid(unsafe_code)]
 #![deny(warnings)]
@@ -20,14 +17,11 @@
 #![deny(unused)]
 #![no_std]
 
-#[cfg(feature = "defmt-03")]
-use defmt::Format;
 use embedded_hal::digital::{OutputPin, StatefulOutputPin};
 use embedded_hal::pwm::SetDutyCycle;
 
 /// Defines errors which can happen when calling [`Motor::drive()`].
 #[derive(PartialEq, Eq, Debug, Copy, Clone)]
-#[cfg_attr(feature = "defmt-03", derive(Format))]
 pub enum MotorError<IN1Error, IN2Error, PWMError> {
     /// An invalid speed has been defined. The speed must be given as a percentage value between 0 and 100 to be valid.
     InvalidSpeed,
@@ -41,15 +35,13 @@ pub enum MotorError<IN1Error, IN2Error, PWMError> {
 
 /// Defines errors which can happen when calling [`Tb6612fng::new()`].
 #[derive(PartialEq, Eq, Debug, Copy, Clone)]
-#[cfg_attr(feature = "defmt-03", derive(Format))]
 pub enum Tb6612fngError<STBYError> {
     /// An error in setting the initial output of the standby pin
     Standby(STBYError),
 }
 
 /// Defines the possible drive commands.
 #[derive(PartialEq, Eq, Debug, Copy, Clone)]
-#[cfg_attr(feature = "defmt-03", derive(Format))]
 pub enum DriveCommand {
     /// Drive forward with the defined speed (in percentage)
     Forward(u8),
@@ -66,7 +58,6 @@ pub enum DriveCommand {
 /// Use the [`Motor`] struct directly if you only have one motor.
 /// See the crate-level comment for further details on when to use what.
 #[derive(Debug)]
-#[cfg_attr(feature = "defmt-03", derive(Format))]
 pub struct Tb6612fng<MAIN1, MAIN2, MAPWM, MBIN1, MBIN2, MBPWM, STBY> {
     /// The first motor, labelled as 'A' on the chip
     pub motor_a: Motor<MAIN1, MAIN2, MAPWM>,
@@ -200,7 +191,6 @@ where
 /// This is unaware of the standby pin. If you plan on using both motors and the standby feature then use the [`Tb6612fng`] struct instead.
 /// See the crate-level comment for further details on when to use what.
 #[derive(Debug)]
-#[cfg_attr(feature = "defmt-03", derive(Format))]
 pub struct Motor<IN1, IN2, PWM> {
     in1: IN1,
     in2: IN2,
@@ -306,9 +296,6 @@ where
             }
         }
 
-        #[cfg(feature = "defmt-03")]
-        defmt::debug!("driving {} with speed {}", drive_command, speed);
-
         self.pwm
             .set_duty_cycle_percent(speed)
             .map_err(MotorError::PwmError)?;