Modify Encoder class API to allow dependency injection (#213)

Signed-off-by: Javier Balloffet <[email protected]>

andino_firmware/src/app.cpp

@@ -71,6 +71,7 @@
 #include "digital_out_arduino.h"
 #include "encoder.h"
 #include "hw.h"
+#include "interrupt_in_arduino.h"
 #include "motor.h"
 #include "pid.h"
 #include "pwm_out_arduino.h"
@@ -92,8 +93,15 @@ PwmOutArduino App::right_motor_backward_pwm_out_(Hw::kRightMotorBackwardGpioPin)
 Motor App::right_motor_(&right_motor_enable_digital_out_, &right_motor_forward_pwm_out_,
                         &right_motor_backward_pwm_out_);
 
-Encoder App::left_encoder_(Hw::kLeftEncoderChannelAGpioPin, Hw::kLeftEncoderChannelBGpioPin);
-Encoder App::right_encoder_(Hw::kRightEncoderChannelAGpioPin, Hw::kRightEncoderChannelBGpioPin);
+InterruptInArduino App::left_encoder_channel_a_interrupt_in_(Hw::kLeftEncoderChannelAGpioPin);
+InterruptInArduino App::left_encoder_channel_b_interrupt_in_(Hw::kLeftEncoderChannelBGpioPin);
+Encoder App::left_encoder_(&left_encoder_channel_a_interrupt_in_,
+                           &left_encoder_channel_b_interrupt_in_);
+
+InterruptInArduino App::right_encoder_channel_a_interrupt_in_(Hw::kRightEncoderChannelAGpioPin);
+InterruptInArduino App::right_encoder_channel_b_interrupt_in_(Hw::kRightEncoderChannelBGpioPin);
+Encoder App::right_encoder_(&right_encoder_channel_a_interrupt_in_,
+                            &right_encoder_channel_b_interrupt_in_);
 
 PID App::left_pid_controller_(Constants::kPidKp, Constants::kPidKd, Constants::kPidKi,
                               Constants::kPidKo, -Constants::kPwmMax, Constants::kPwmMax);
@@ -110,8 +118,8 @@ void App::setup() {
 
   Serial.begin(Constants::kBaudrate);
 
-  left_encoder_.init();
-  right_encoder_.init();
+  left_encoder_.begin();
+  right_encoder_.begin();
 
   left_motor_.begin();
   left_motor_.enable(true);

andino_firmware/src/app.h

@@ -31,6 +31,7 @@
 
 #include "digital_out_arduino.h"
 #include "encoder.h"
+#include "interrupt_in_arduino.h"
 #include "motor.h"
 #include "pid.h"
 #include "pwm_out_arduino.h"
@@ -96,8 +97,14 @@ class App {
   static PwmOutArduino right_motor_backward_pwm_out_;
   static Motor right_motor_;
 
-  /// Encoders (one per wheel).
+  /// Left wheel encoder.
+  static InterruptInArduino left_encoder_channel_a_interrupt_in_;
+  static InterruptInArduino left_encoder_channel_b_interrupt_in_;
   static Encoder left_encoder_;
+
+  /// Right wheel encoder.
+  static InterruptInArduino right_encoder_channel_a_interrupt_in_;
+  static InterruptInArduino right_encoder_channel_b_interrupt_in_;
   static Encoder right_encoder_;
 
   /// PID controllers (one per wheel).

andino_firmware/src/encoder.cpp

@@ -66,7 +66,7 @@
 
 #include <stdint.h>
 
-#include "interrupt_in_arduino.h"
+#include "interrupt_in.h"
 
 namespace andino {
 
@@ -89,17 +89,17 @@ void Encoder::callback_1() {
 Encoder* Encoder::instances_[kInstancesMax] = {nullptr, nullptr};
 int Encoder::instance_count_ = 0;
 
-void Encoder::init() {
+void Encoder::begin() {
   // The current implementation only supports two instances of this class to be constructed. This
   // prevents reaching a buffer overflow.
   if (instance_count_ == kInstancesMax) {
     return;
   }
 
-  channel_a_interrupt_in_.begin();
-  channel_a_interrupt_in_.attach(kCallbacks[instance_count_]);
-  channel_b_interrupt_in_.begin();
-  channel_b_interrupt_in_.attach(kCallbacks[instance_count_]);
+  channel_a_interrupt_in_->begin();
+  channel_a_interrupt_in_->attach(kCallbacks[instance_count_]);
+  channel_b_interrupt_in_->begin();
+  channel_b_interrupt_in_->attach(kCallbacks[instance_count_]);
 
   instances_[instance_count_] = this;
   instance_count_++;
@@ -112,7 +112,7 @@ void Encoder::reset() { count_ = 0L; }
 void Encoder::callback() {
   // Read the current channels state into the lowest 2 bits of the encoder state.
   state_ <<= 2;
-  state_ |= (channel_b_interrupt_in_.read() << 1) | channel_a_interrupt_in_.read();
+  state_ |= (channel_b_interrupt_in_->read() << 1) | channel_a_interrupt_in_->read();
 
   // Update the encoder count accordingly.
   count_ += kTicksDelta[(state_ & 0x0F)];

andino_firmware/src/encoder.h

@@ -66,7 +66,7 @@
 
 #include <stdint.h>
 
-#include "interrupt_in_arduino.h"
+#include "interrupt_in.h"
 
 namespace andino {
 
@@ -77,15 +77,16 @@ class Encoder {
  public:
   /// @brief Constructs a new Encoder object.
   ///
-  /// @param a_gpio_pin Encoder channel A GPIO pin.
-  /// @param b_gpio_pin Encoder channel B GPIO pin.
-  Encoder(int a_gpio_pin, int b_gpio_pin)
-      : channel_a_interrupt_in_(a_gpio_pin), channel_b_interrupt_in_(b_gpio_pin) {}
+  /// @param channel_a_interrupt_in Digital interrupt input connected to encoder channel A pin.
+  /// @param channel_b_interrupt_in Digital interrupt input connected to encoder channel B pin.
+  Encoder(const InterruptIn* channel_a_interrupt_in, const InterruptIn* channel_b_interrupt_in)
+      : channel_a_interrupt_in_(channel_a_interrupt_in),
+        channel_b_interrupt_in_(channel_b_interrupt_in) {}
 
   /// @brief Initializes the encoder.
-  void init();
+  void begin();
 
-  /// @brief Returns the ticks count value.
+  /// @brief Gets the ticks count value.
   ///
   /// @return Ticks count value.
   long read();
@@ -130,7 +131,7 @@ class Encoder {
   /// Static wrapper that redirects to the second instance callback method.
   static void callback_1();
 
-  /// Channels GPIO interrupt callback.
+  /// Channels interrupt callback.
   void callback();
 
   /// Holds references to the constructed Encoder instances.
@@ -139,11 +140,11 @@ class Encoder {
   /// Number of constructed Encoder instances.
   static int instance_count_;
 
-  /// Interrupt input connected to encoder channel A pin.
-  InterruptInArduino channel_a_interrupt_in_;
+  /// Digital interrupt input connected to encoder channel A pin.
+  const InterruptIn* channel_a_interrupt_in_;
 
-  /// Interrupt input connected to encoder channel B pin.
-  InterruptInArduino channel_b_interrupt_in_;
+  /// Digital interrupt input connected to encoder channel B pin.
+  const InterruptIn* channel_b_interrupt_in_;
 
   /// Encoder state. It contains both the current and previous channels state readings:
   ///   +------+-----+-----+-----+-----+-----+-----+-----+-----+