Merge pull request #178 from jamwaffles/qei-configuration

Add configuration options to QEI interface

Author: therealprof

examples/qei.rs

@@ -8,13 +8,8 @@ use panic_semihosting as _;
 
 use cortex_m_semihosting::hprintln;
 
-use stm32f1xx_hal::{
-    prelude::*,
-    pac,
-    delay::Delay,
-    timer::Timer,
-};
 use cortex_m_rt::entry;
+use stm32f1xx_hal::{delay::Delay, pac, prelude::*, qei::QeiOptions, timer::Timer};
 
 #[entry]
 fn main() -> ! {
@@ -43,8 +38,11 @@ fn main() -> ! {
     let c1 = gpiob.pb6;
     let c2 = gpiob.pb7;
 
-    let qei = Timer::tim4(dp.TIM4, &clocks, &mut rcc.apb1)
-        .qei((c1, c2), &mut afio.mapr);
+    let qei = Timer::tim4(dp.TIM4, &clocks, &mut rcc.apb1).qei(
+        (c1, c2),
+        &mut afio.mapr,
+        QeiOptions::default(),
+    );
     let mut delay = Delay::new(cp.SYST, clocks);
 
     loop {

src/qei.rs

@@ -4,96 +4,152 @@
   NOTE: In some cases you need to specify remap you need, especially for TIM2
   (see [Alternate function remapping](super::timer)):
 */
-
 use core::u16;
 
 use core::marker::PhantomData;
 
 use crate::hal::{self, Direction};
-#[cfg(any(
-    feature = "stm32f100",
-    feature = "stm32f103",
-    feature = "stm32f105",
-))]
+#[cfg(any(feature = "stm32f100", feature = "stm32f103", feature = "stm32f105",))]
 use crate::pac::TIM1;
-use crate::pac::{TIM2, TIM3};
 #[cfg(feature = "medium")]
 use crate::pac::TIM4;
+use crate::pac::{TIM2, TIM3};
 
 use crate::afio::MAPR;
 
-use crate::timer::{Timer, sealed::Remap};
 use crate::pwm_input::Pins;
+use crate::timer::{sealed::Remap, Timer};
+
+/// SMS (Slave Mode Selection) register
+#[derive(Copy, Clone, Debug)]
+pub enum SlaveMode {
+    /// Counter counts up/down on TI2FP1 edge depending on TI1FP2 level.
+    EncoderMode1 = 0b001,
+    /// Encoder mode 2 - Counter counts up/down on TI1FP2 edge depending on TI2FP1 level.
+    EncoderMode2 = 0b010,
+    /// Encoder mode 3 - Counter counts up/down on both TI1FP1 and TI2FP2 edges depending on the
+    /// level of the other input.
+    EncoderMode3 = 0b011,
+    /// Reset Mode - Rising edge of the selected trigger input (TRGI) reinitializes the counter and
+    /// generates an update of the registers.
+    ResetMode = 0b100,
+    /// Trigger Mode - The counter starts at a rising edge of the trigger TRGI (but it is not
+    /// reset). Only the start of the counter is controlled.
+    TriggerMode = 0b110,
+    /// External Clock Mode 1 - Rising edges of the selected trigger (TRGI) clock the counter.
+    ExternalClockMode1 = 0b111,
+}
+
+/// Quadrature Encoder Interface (QEI) options
+///
+/// The `Default` implementation provides a configuration for a 4-count pulse which counts from
+/// 0-65535. The counter wraps back to 0 on overflow.
+#[derive(Copy, Clone, Debug)]
+pub struct QeiOptions {
+    /// Encoder slave mode
+    pub slave_mode: SlaveMode,
+
+    /// Autoreload value
+    ///
+    /// This value allows the maximum count to be configured, up to 65535. Setting a lower value
+    /// will overflow the counter to 0 sooner.
+    pub auto_reload_value: u16,
+}
+
+impl Default for QeiOptions {
+    fn default() -> Self {
+        Self {
+            slave_mode: SlaveMode::EncoderMode3,
+            auto_reload_value: u16::MAX,
+        }
+    }
+}
 
 pub struct Qei<TIM, REMAP, PINS> {
     tim: TIM,
     pins: PINS,
     _remap: PhantomData<REMAP>,
 }
 
-#[cfg(any(
-    feature = "stm32f100",
-    feature = "stm32f103",
-    feature = "stm32f105",
-))]
+#[cfg(any(feature = "stm32f100", feature = "stm32f103", feature = "stm32f105",))]
 impl Timer<TIM1> {
-    pub fn qei<REMAP, PINS>(self, pins: PINS, mapr: &mut MAPR) -> Qei<TIM1, REMAP, PINS>
+    pub fn qei<REMAP, PINS>(
+        self,
+        pins: PINS,
+        mapr: &mut MAPR,
+        options: QeiOptions,
+    ) -> Qei<TIM1, REMAP, PINS>
     where
         REMAP: Remap<Periph = TIM1>,
         PINS: Pins<REMAP>,
     {
         mapr.modify_mapr(|_, w| unsafe { w.tim1_remap().bits(REMAP::REMAP) });
 
         let Self { tim, clk: _ } = self;
-        Qei::_tim1(tim, pins)
+        Qei::_tim1(tim, pins, options)
     }
 }
 
 impl Timer<TIM2> {
-    pub fn qei<REMAP, PINS>(self, pins: PINS, mapr: &mut MAPR) -> Qei<TIM2, REMAP, PINS>
+    pub fn qei<REMAP, PINS>(
+        self,
+        pins: PINS,
+        mapr: &mut MAPR,
+        options: QeiOptions,
+    ) -> Qei<TIM2, REMAP, PINS>
     where
         REMAP: Remap<Periph = TIM2>,
         PINS: Pins<REMAP>,
     {
         mapr.modify_mapr(|_, w| unsafe { w.tim2_remap().bits(REMAP::REMAP) });
 
         let Self { tim, clk: _ } = self;
-        Qei::_tim2(tim, pins)
+        Qei::_tim2(tim, pins, options)
     }
 }
 
 impl Timer<TIM3> {
-    pub fn qei<REMAP, PINS>(self, pins: PINS, mapr: &mut MAPR) -> Qei<TIM3, REMAP, PINS>
+    pub fn qei<REMAP, PINS>(
+        self,
+        pins: PINS,
+        mapr: &mut MAPR,
+        options: QeiOptions,
+    ) -> Qei<TIM3, REMAP, PINS>
     where
         REMAP: Remap<Periph = TIM3>,
         PINS: Pins<REMAP>,
     {
         mapr.modify_mapr(|_, w| unsafe { w.tim3_remap().bits(REMAP::REMAP) });
 
         let Self { tim, clk: _ } = self;
-        Qei::_tim3(tim, pins)
+        Qei::_tim3(tim, pins, options)
     }
 }
 
 #[cfg(feature = "medium")]
 impl Timer<TIM4> {
-    pub fn qei<REMAP, PINS>(self, pins: PINS, mapr: &mut MAPR) -> Qei<TIM4, REMAP, PINS>
+    pub fn qei<REMAP, PINS>(
+        self,
+        pins: PINS,
+        mapr: &mut MAPR,
+        options: QeiOptions,
+    ) -> Qei<TIM4, REMAP, PINS>
     where
         REMAP: Remap<Periph = TIM4>,
         PINS: Pins<REMAP>,
     {
         mapr.modify_mapr(|_, w| w.tim4_remap().bit(REMAP::REMAP == 1));
 
         let Self { tim, clk: _ } = self;
-        Qei::_tim4(tim, pins)
+        Qei::_tim4(tim, pins, options)
     }
 }
 
 macro_rules! hal {
     ($($TIMX:ident: ($timX:ident, $timXen:ident, $timXrst:ident),)+) => {
         $(
             impl<REMAP, PINS> Qei<$TIMX, REMAP, PINS> {
-                fn $timX(tim: $TIMX, pins: PINS) -> Self {
+                fn $timX(tim: $TIMX, pins: PINS, options: QeiOptions) -> Self {
                     // Configure TxC1 and TxC2 as captures
                     tim.ccmr1_input().write(|w| w.cc1s().ti1().cc2s().ti2());
 
@@ -110,9 +166,9 @@ macro_rules! hal {
                     });
 
                     // configure as quadrature encoder
-                    tim.smcr.write(|w| w.sms().bits(3));
+                    tim.smcr.write(|w| w.sms().bits(options.slave_mode as u8));
 
-                    tim.arr.write(|w| w.arr().bits(u16::MAX));
+                    tim.arr.write(|w| w.arr().bits(options.auto_reload_value));
                     tim.cr1.write(|w| w.cen().set_bit());
 
                     Qei { tim, pins, _remap: PhantomData }
@@ -143,11 +199,7 @@ macro_rules! hal {
     }
 }
 
-#[cfg(any(
-    feature = "stm32f100",
-    feature = "stm32f103",
-    feature = "stm32f105",
-))]
+#[cfg(any(feature = "stm32f100", feature = "stm32f103", feature = "stm32f105",))]
 hal! {
     TIM1: (_tim1, tim1en, tim1rst),
 }