Add PCInt class

andino_firmware/src/encoder_driver.cpp

@@ -70,13 +70,15 @@
 #include "Arduino.h"
 #include "commands.h"
 #include "hw.h"
+#include "pcint.h"
 
 volatile long left_enc_pos = 0L;
 volatile long right_enc_pos = 0L;
-static const int8_t ENC_STATES[] = {0, 1, -1, 0, -1, 0, 0, 1, 1, 0, 0, -1, 0, -1, 1, 0};  // encoder lookup table
+static const int8_t ENC_STATES[] = {0, 1, -1, 0,  -1, 0,  0, 1,
+                                    1, 0, 0,  -1, 0,  -1, 1, 0};  // encoder lookup table
 
 /* Interrupt routine for LEFT encoder, taking care of actual counting */
-ISR(PCINT2_vect) {
+void left_encoder_cb() {
   static uint8_t enc_last = 0;
 
   enc_last <<= 2;                      // shift previous state two places
@@ -86,7 +88,7 @@ ISR(PCINT2_vect) {
 }
 
 /* Interrupt routine for RIGHT encoder, taking care of actual counting */
-ISR(PCINT1_vect) {
+void right_encoder_cb() {
   static uint8_t enc_last = 0;
 
   enc_last <<= 2;                      // shift previous state two places
@@ -96,25 +98,15 @@ ISR(PCINT1_vect) {
 }
 
 void initEncoders() {
-  // set as inputs
-  DDRD &= ~(1 << LEFT_ENCODER_A_GPIO_PIN);
-  DDRD &= ~(1 << LEFT_ENCODER_B_GPIO_PIN);
-  DDRC &= ~(1 << RIGHT_ENCODER_A_GPIO_PIN);
-  DDRC &= ~(1 << RIGHT_ENCODER_B_GPIO_PIN);
-
-  // enable pull up resistors
-  PORTD |= (1 << LEFT_ENCODER_A_GPIO_PIN);
-  PORTD |= (1 << LEFT_ENCODER_B_GPIO_PIN);
-  PORTC |= (1 << RIGHT_ENCODER_A_GPIO_PIN);
-  PORTC |= (1 << RIGHT_ENCODER_B_GPIO_PIN);
-
-  // tell pin change mask to listen to left encoder pins
-  PCMSK2 |= (1 << LEFT_ENCODER_A_GPIO_PIN) | (1 << LEFT_ENCODER_B_GPIO_PIN);
-  // tell pin change mask to listen to right encoder pins
-  PCMSK1 |= (1 << RIGHT_ENCODER_A_GPIO_PIN) | (1 << RIGHT_ENCODER_B_GPIO_PIN);
-
-  // enable PCINT1 and PCINT2 interrupt in the general interrupt mask
-  PCICR |= (1 << PCIE1) | (1 << PCIE2);
+  pinMode(LEFT_ENCODER_A_GPIO_PIN, INPUT_PULLUP);
+  pinMode(LEFT_ENCODER_B_GPIO_PIN, INPUT_PULLUP);
+  pinMode(RIGHT_ENCODER_A_GPIO_PIN, INPUT_PULLUP);
+  pinMode(RIGHT_ENCODER_B_GPIO_PIN, INPUT_PULLUP);
+
+  andino::PCInt::attach_interrupt(LEFT_ENCODER_A_GPIO_PIN, left_encoder_cb);
+  andino::PCInt::attach_interrupt(LEFT_ENCODER_B_GPIO_PIN, left_encoder_cb);
+  andino::PCInt::attach_interrupt(RIGHT_ENCODER_A_GPIO_PIN, right_encoder_cb);
+  andino::PCInt::attach_interrupt(RIGHT_ENCODER_B_GPIO_PIN, right_encoder_cb);
 }
 
 /* Wrap the encoder reading function */

andino_firmware/src/hw.h

@@ -29,17 +29,17 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #pragma once
 
-// PC4 (pin A4), RIGHT ENCODER PIN A
-#define RIGHT_ENCODER_A_GPIO_PIN PC4
+// PC4 (pin 18), RIGHT ENCODER PIN A
+#define RIGHT_ENCODER_A_GPIO_PIN 18
 
-// PC5 (pin A5), RIGHT ENCODER PIN B
-#define RIGHT_ENCODER_B_GPIO_PIN PC5
+// PC5 (pin 19), RIGHT ENCODER PIN B
+#define RIGHT_ENCODER_B_GPIO_PIN 19
 
 // PD2 (pin 2), LEFT ENCODER PIN A
-#define LEFT_ENCODER_A_GPIO_PIN PD2
+#define LEFT_ENCODER_A_GPIO_PIN 2
 
 // PD3 (pin 3), LEFT ENCODER PIN B
-#define LEFT_ENCODER_B_GPIO_PIN PD3
+#define LEFT_ENCODER_B_GPIO_PIN 3
 
 // PD5 (pin 5), RIGHT MOTOR DRIVER BACKWARD PIN
 #define RIGHT_MOTOR_BACKWARD_GPIO_PIN 5

andino_firmware/src/pcint.cpp

@@ -0,0 +1,79 @@
+// BSD 3-Clause License
+//
+// Copyright (c) 2023, Ekumen Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this
+//    list of conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its
+//    contributors may be used to endorse or promote products derived from
+//    this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#include "pcint.h"
+
+#include "Arduino.h"
+
+static andino::PCInt::InterruptCallback g_callbacks[3] = {nullptr};
+
+ISR(PCINT0_vect) {
+  if (g_callbacks[0] != nullptr) {
+    g_callbacks[0]();
+  }
+}
+
+ISR(PCINT1_vect) {
+  if (g_callbacks[1] != nullptr) {
+    g_callbacks[1]();
+  }
+}
+
+ISR(PCINT2_vect) {
+  if (g_callbacks[2] != nullptr) {
+    g_callbacks[2]();
+  }
+}
+
+namespace andino {
+
+constexpr volatile uint8_t* PCInt::kPortToPCMask[];
+
+void PCInt::attach_interrupt(uint8_t pin, InterruptCallback callback) {
+  uint8_t bit_mask = digitalPinToBitMask(pin);
+  uint8_t port = digitalPinToPort(pin);
+
+  if (port == NOT_A_PORT) {
+    return;
+  }
+
+  // Ports B, C and D values are 2, 3 and 4 correspondingly.
+  port -= 2;
+
+  // Set corresponding bit in the appropriate Pin Change Mask register.
+  *(kPortToPCMask[port]) |= bit_mask;
+
+  // Set corresponding bit in the Pin Change Interrupt Control register.
+  PCICR |= 0x01 << port;
+
+  // Set callback function.
+  g_callbacks[port] = callback;
+}
+
+}  // namespace andino

andino_firmware/src/pcint.h

@@ -0,0 +1,56 @@
+// BSD 3-Clause License
+//
+// Copyright (c) 2023, Ekumen Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this
+//    list of conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its
+//    contributors may be used to endorse or promote products derived from
+//    this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#pragma once
+
+#include <stdint.h>
+
+#include "Arduino.h"
+
+namespace andino {
+
+/// @brief This class provides a simple way to set and use Pin Change Interrupts.
+class PCInt {
+ public:
+  /// @brief Interrupt callback type.
+  typedef void (*InterruptCallback)();
+
+  /// @brief Attaches an interrupt callback.
+  /// @note Only one callback per port is supported.
+  ///
+  /// @param pin Pin of interest.
+  /// @param callback Callback function.
+  static void attach_interrupt(uint8_t pin, InterruptCallback callback);
+
+ private:
+  /// Map between ports and Pin Change Mask registers.
+  static constexpr volatile uint8_t* kPortToPCMask[]{&PCMSK0, &PCMSK1, &PCMSK2};
+};
+
+}  // namespace andino