Add RGBLED and Button libraries

"RGBLED" PWMs 3 pins as a single RGB LED and exposes methods to set the colour via HSV/RGB.

"Button" handles tracking the state and changed state of a single GPIO button, in addition to supporting auto-repeat for held-down buttons.

common/pimoroni_common.hpp

@@ -1,6 +1,7 @@
 #pragma once
 #include <stdint.h>
 #include <climits>
+#include "pico/stdlib.h"
 
 #define PIMORONI_I2C_DEFAULT_INSTANCE i2c0
 #define PIMORONI_SPI_DEFAULT_INSTANCE spi0
@@ -39,4 +40,13 @@ namespace pimoroni {
       BREAKOUT_GARDEN,
       PICO_EXPLORER
     };
+
+    enum Polarity {
+      ACTIVE_LOW = 0,
+      ACTIVE_HIGH = 1
+    };
+
+    inline uint32_t millis() {
+      return to_ms_since_boot(get_absolute_time());
+    }
 }

drivers/CMakeLists.txt

@@ -13,3 +13,5 @@ add_subdirectory(is31fl3731)
 add_subdirectory(fatfs)
 add_subdirectory(sdcard)
 add_subdirectory(as7262)
+add_subdirectory(button)
+add_subdirectory(rgbled)

drivers/button/CMakeLists.txt

@@ -0,0 +1 @@
+include(button.cmake)

drivers/button/button.cmake

@@ -0,0 +1,10 @@
+add_library(button INTERFACE)
+
+target_sources(button INTERFACE
+  ${CMAKE_CURRENT_LIST_DIR}/button.cpp
+)
+
+target_include_directories(button INTERFACE ${CMAKE_CURRENT_LIST_DIR})
+
+# Pull in pico libraries that we need
+target_link_libraries(button INTERFACE pico_stdlib)

drivers/button/button.cpp

@@ -0,0 +1,47 @@
+#include "button.hpp"
+
+namespace pimoroni {
+    bool Button::raw() {
+      if(polarity == Polarity::ACTIVE_LOW){
+        return !gpio_get(pin);
+      } else {
+        return gpio_get(pin);
+      }
+    }
+
+    bool Button::read() {
+      auto time = millis();
+      bool state = raw();
+      bool changed = state != last_state;
+      last_state = state;
+
+      if(changed) {
+        if(state) {
+          pressed_time = time;
+          pressed = true;
+          last_time = time;
+          return true;
+        }
+        else {
+          pressed_time = 0;
+          pressed = false;
+          last_time = 0;
+        }
+      }
+      // Shortcut for no auto-repeat
+      if(repeat_time == 0) return false;
+
+      if(pressed) {
+        uint32_t repeat_rate = repeat_time;
+        if(hold_time > 0 && time - pressed_time > hold_time) {
+          repeat_rate /= 3;
+        }
+        if(time - last_time > repeat_rate) {
+          last_time = time;
+          return true;
+        }
+      }
+
+      return false;
+    }
+};

drivers/button/button.hpp

@@ -0,0 +1,35 @@
+#pragma once
+
+#include <stdint.h>
+#include "pico/stdlib.h"
+#include "common/pimoroni_common.hpp"
+
+namespace pimoroni {
+
+  class Button {
+  public:
+    Button(uint pin, Polarity polarity=Polarity::ACTIVE_LOW, uint32_t repeat_time=200, uint32_t hold_time=1000) :
+    pin(pin), polarity(polarity), repeat_time(repeat_time), hold_time(hold_time) {
+      gpio_set_function(pin, GPIO_FUNC_SIO);
+      gpio_set_dir(pin, GPIO_IN);
+      if (polarity == Polarity::ACTIVE_LOW) {
+        gpio_pull_up(pin);
+      }
+      else {
+        gpio_pull_down(pin);
+      }
+    };
+    bool raw();
+    bool read();
+  private:
+    uint pin;
+    Polarity polarity;
+    uint32_t repeat_time;
+    uint32_t hold_time;
+    bool pressed = false;
+    bool last_state = false;
+    uint32_t pressed_time = 0;
+    uint32_t last_time = 0;
+  };
+
+}

drivers/rgbled/CMakeLists.txt

@@ -0,0 +1 @@
+include(rgbled.cmake)

drivers/rgbled/rgbled.cmake

@@ -0,0 +1,10 @@
+add_library(rgbled INTERFACE)
+
+target_sources(rgbled INTERFACE
+  ${CMAKE_CURRENT_LIST_DIR}/rgbled.cpp
+)
+
+target_include_directories(rgbled INTERFACE ${CMAKE_CURRENT_LIST_DIR})
+
+# Pull in pico libraries that we need
+target_link_libraries(rgbled INTERFACE pico_stdlib hardware_pwm)

drivers/rgbled/rgbled.cpp

@@ -0,0 +1,52 @@
+#include "rgbled.hpp"
+
+namespace pimoroni {
+  void RGBLED::set_rgb(uint8_t r, uint8_t g, uint8_t b) {
+    led_r = r;
+    led_g = g;
+    led_b = b;
+    update_pwm();
+  }
+
+  void RGBLED::set_brightness(uint8_t brightness) {
+    led_brightness = brightness;
+    update_pwm();
+  }
+
+  void RGBLED::set_hsv(float h, float s, float v) {
+    float i = floor(h * 6.0f);
+    float f = h * 6.0f - i;
+    v *= 255.0f;
+    uint8_t p = v * (1.0f - s);
+    uint8_t q = v * (1.0f - f * s);
+    uint8_t t = v * (1.0f - (1.0f - f) * s);
+
+    switch (int(i) % 6) {
+      case 0: led_r = v; led_g = t; led_b = p; break;
+      case 1: led_r = q; led_g = v; led_b = p; break;
+      case 2: led_r = p; led_g = v; led_b = t; break;
+      case 3: led_r = p; led_g = q; led_b = v; break;
+      case 4: led_r = t; led_g = p; led_b = v; break;
+      case 5: led_r = v; led_g = p; led_b = q; break;
+    }
+
+    update_pwm();
+  }
+
+  void RGBLED::update_pwm() {
+    uint16_t r16 = GAMMA[led_r];
+    uint16_t g16 = GAMMA[led_g];
+    uint16_t b16 = GAMMA[led_b];
+    r16 *= led_brightness;
+    g16 *= led_brightness;
+    b16 *= led_brightness;
+    if(polarity == Polarity::ACTIVE_LOW) {
+      r16 = UINT16_MAX - r16;
+      g16 = UINT16_MAX - g16;
+      b16 = UINT16_MAX - b16;
+    }
+    pwm_set_gpio_level(pin_r, r16);
+    pwm_set_gpio_level(pin_g, g16);
+    pwm_set_gpio_level(pin_b, b16);
+  }
+};

drivers/rgbled/rgbled.hpp

@@ -0,0 +1,68 @@
+#pragma once
+
+#include <stdint.h>
+#include <math.h>
+
+#include "pico/stdlib.h"
+#include "hardware/pwm.h"
+#include "common/pimoroni_common.hpp"
+
+namespace pimoroni {
+
+  class RGBLED {
+  public:
+    RGBLED(uint pin_r, uint pin_g, uint pin_b, Polarity polarity=Polarity::ACTIVE_LOW, uint8_t brightness=255) :
+    pin_r(pin_r), pin_g(pin_g), pin_b(pin_b), polarity(polarity), led_brightness(brightness) {
+      pwm_cfg = pwm_get_default_config();
+      pwm_config_set_wrap(&pwm_cfg, UINT16_MAX);
+
+      pwm_init(pwm_gpio_to_slice_num(pin_r), &pwm_cfg, true);
+      gpio_set_function(pin_r, GPIO_FUNC_PWM);
+
+      pwm_init(pwm_gpio_to_slice_num(pin_g), &pwm_cfg, true);
+      gpio_set_function(pin_g, GPIO_FUNC_PWM);
+
+      pwm_init(pwm_gpio_to_slice_num(pin_b), &pwm_cfg, true);
+      gpio_set_function(pin_b, GPIO_FUNC_PWM);
+    };
+    ~RGBLED() {
+      gpio_set_function(pin_r, GPIO_FUNC_NULL);
+      gpio_set_function(pin_g, GPIO_FUNC_NULL);
+      gpio_set_function(pin_b, GPIO_FUNC_NULL);
+    }
+    void set_rgb(uint8_t r, uint8_t g, uint8_t b);
+    void set_hsv(float h, float s, float v);
+    void set_brightness(uint8_t brightness);
+  private:
+    uint pin_r;
+    uint pin_g;
+    uint pin_b;
+    Polarity polarity;
+    pwm_config pwm_cfg;
+
+    uint8_t led_r;
+    uint8_t led_g;
+    uint8_t led_b;
+    uint8_t led_brightness = 255;
+    const uint8_t GAMMA[256] = {
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2,
+      2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5,
+      6, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 11, 11,
+      11, 12, 12, 13, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18,
+      19, 19, 20, 21, 21, 22, 22, 23, 23, 24, 25, 25, 26, 27, 27, 28,
+      29, 29, 30, 31, 31, 32, 33, 34, 34, 35, 36, 37, 37, 38, 39, 40,
+      40, 41, 42, 43, 44, 45, 46, 46, 47, 48, 49, 50, 51, 52, 53, 54,
+      55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70,
+      71, 72, 73, 74, 76, 77, 78, 79, 80, 81, 83, 84, 85, 86, 88, 89,
+      90, 91, 93, 94, 95, 96, 98, 99, 100, 102, 103, 104, 106, 107, 109, 110,
+      111, 113, 114, 116, 117, 119, 120, 121, 123, 124, 126, 128, 129, 131, 132, 134,
+      135, 137, 138, 140, 142, 143, 145, 146, 148, 150, 151, 153, 155, 157, 158, 160,
+      162, 163, 165, 167, 169, 170, 172, 174, 176, 178, 179, 181, 183, 185, 187, 189,
+      191, 193, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220,
+      222, 224, 227, 229, 231, 233, 235, 237, 239, 241, 244, 246, 248, 250, 252, 255};
+
+    void update_pwm();
+  };
+
+}