Pager: Add rudamentary keyboard backlight

Boards/LilygoTLoraPager/Source/hal/TpagerKeyboard.cpp

@@ -12,6 +12,7 @@
 #define ENCODER_A       GPIO_NUM_40
 #define ENCODER_B       GPIO_NUM_41
 #define ENCODER_ENTER   GPIO_NUM_7
+#define BACKLIGHT       GPIO_NUM_46
 
 #define KB_ROWS 4
 #define KB_COLS 11
@@ -63,6 +64,7 @@ static void encoder_read_callback(lv_indev_t* indev, lv_indev_data_t* data) {
     static int enter_filter = 0;
     const int pulses_click = 4;
     static int pulses_prev = 0;
+    bool anyinput = false;
 
     // Defaults
     data->enc_diff = 0;
@@ -73,6 +75,7 @@ static void encoder_read_callback(lv_indev_t* indev, lv_indev_data_t* data) {
     if ((pulse_diff > pulses_click) || (pulse_diff < -pulses_click)) {
         data->enc_diff = pulse_diff / pulses_click;
         pulses_prev = pulses;
+        anyinput = true;
     }
 
     bool enter = !gpio_get_level(ENCODER_ENTER);
@@ -85,6 +88,11 @@ static void encoder_read_callback(lv_indev_t* indev, lv_indev_data_t* data) {
 
     if (enter_filter == enter_filter_threshold) {
         data->state = LV_INDEV_STATE_PRESSED;
+        anyinput = true;
+    }
+
+    if (anyinput) {
+        kb->makeBacklightImpulse();
     }
 }
 
@@ -93,8 +101,10 @@ void TpagerKeyboard::processKeyboard() {
     static bool sym_pressed = false;
     static bool cap_toggle = false;
     static bool cap_toggle_armed = true;
+    bool anykey_pressed = false;
 
     if (keypad->update()) {
+        anykey_pressed = (keypad->pressed_key_count > 0);
         for (int i=0; i < keypad->pressed_key_count; i++) {
             auto row = keypad->pressed_list[i].row;
             auto col = keypad->pressed_list[i].col;
@@ -113,7 +123,7 @@ void TpagerKeyboard::processKeyboard() {
             cap_toggle_armed = false;
         }
 
-        for (int i=0; i<keypad->pressed_key_count; i++) {
+        for (int i=0; i < keypad->pressed_key_count; i++) {
             auto row = keypad->pressed_list[i].row;
             auto col = keypad->pressed_list[i].col;
             auto hold = keypad->pressed_list[i].hold_time;
@@ -129,7 +139,7 @@ void TpagerKeyboard::processKeyboard() {
             if (chr != '\0') xQueueSend(keyboardMsg, (void *)&chr, portMAX_DELAY);
         }
 
-        for (int i=0; i<keypad->released_key_count; i++) {
+        for (int i=0; i < keypad->released_key_count; i++) {
             auto row = keypad->released_list[i].row;
             auto col = keypad->released_list[i].col;
 
@@ -144,10 +154,15 @@ void TpagerKeyboard::processKeyboard() {
         if ((!sym_pressed && !shift_pressed) && !cap_toggle_armed) {
             cap_toggle_armed = true;
         }
+
+        if (anykey_pressed) {
+            makeBacklightImpulse();
+        }
     }
 }
 
 bool TpagerKeyboard::start(lv_display_t* display) {
+    backlightOkay = initBacklight(BACKLIGHT, 30000, LEDC_TIMER_0, LEDC_CHANNEL_1);
     initEncoder();
     keypad->init(KB_ROWS, KB_COLS);
     gpio_input_enable(ENCODER_ENTER);
@@ -157,6 +172,11 @@ bool TpagerKeyboard::start(lv_display_t* display) {
         processKeyboard();
     });
 
+    assert(backlightImpulseTimer == nullptr);
+    backlightImpulseTimer = std::make_unique<tt::Timer>(tt::Timer::Type::Periodic, [this] {
+        processBacklightImpuse();
+    });
+
     kbHandle = lv_indev_create();
     lv_indev_set_type(kbHandle, LV_INDEV_TYPE_KEYPAD);
     lv_indev_set_read_cb(kbHandle, &keyboard_read_callback);
@@ -170,16 +190,20 @@ bool TpagerKeyboard::start(lv_display_t* display) {
     lv_indev_set_user_data(encHandle, this);
 
     inputTimer->start(20 / portTICK_PERIOD_MS);
+    backlightImpulseTimer->start(50 / portTICK_PERIOD_MS);
 
     return true;
 }
 
 bool TpagerKeyboard::stop() {
     assert(inputTimer);
-
     inputTimer->stop();
     inputTimer = nullptr;
 
+    assert(backlightImpulseTimer);
+    backlightImpulseTimer->stop();
+    backlightImpulseTimer = nullptr;
+
     lv_indev_delete(kbHandle);
     kbHandle = nullptr;
     lv_indev_delete(encHandle);
@@ -243,6 +267,67 @@ int TpagerKeyboard::getEncoderPulses() {
 }
 
 
+bool TpagerKeyboard::initBacklight(gpio_num_t pin, uint32_t frequencyHz, ledc_timer_t timer, ledc_channel_t channel) {
+    backlightPin = pin;
+    backlightTimer = timer;
+    backlightChannel = channel;
+
+    ledc_timer_config_t ledc_timer = {
+        .speed_mode = LEDC_LOW_SPEED_MODE,
+        .duty_resolution = LEDC_TIMER_8_BIT,
+        .timer_num = backlightTimer,
+        .freq_hz = frequencyHz,
+        .clk_cfg = LEDC_AUTO_CLK,
+        .deconfigure = false
+    };
+
+    if (ledc_timer_config(&ledc_timer) != ESP_OK) {
+        TT_LOG_E(TAG, "Backlight timer config failed");
+        return false;
+    }
+
+    ledc_channel_config_t ledc_channel = {
+        .gpio_num = backlightPin,
+        .speed_mode = LEDC_LOW_SPEED_MODE,
+        .channel = backlightChannel,
+        .intr_type = LEDC_INTR_DISABLE,
+        .timer_sel = backlightTimer,
+        .duty = 0,
+        .hpoint = 0,
+        .sleep_mode = LEDC_SLEEP_MODE_NO_ALIVE_NO_PD,
+        .flags = {
+            .output_invert = 0
+        }
+    };
+
+    if (ledc_channel_config(&ledc_channel) != ESP_OK) {
+        TT_LOG_E(TAG, "Backlight channel config failed");
+    }
+
+    return true;
+}
+
+bool TpagerKeyboard::setBacklightDuty(uint8_t duty) {
+    if (!backlightOkay) {
+        TT_LOG_E(TAG, "Backlight not ready");
+        return false;
+    }
+    return (ledc_set_duty(LEDC_LOW_SPEED_MODE, backlightChannel, duty) == ESP_OK) &&
+    (ledc_update_duty(LEDC_LOW_SPEED_MODE, backlightChannel) == ESP_OK);
+}
+
+void TpagerKeyboard::makeBacklightImpulse() {
+    backlightImpulseDuty = 255;
+    setBacklightDuty(backlightImpulseDuty);
+}
+
+void TpagerKeyboard::processBacklightImpuse() {
+    if (backlightImpulseDuty > 64) {
+        backlightImpulseDuty--;
+        setBacklightDuty(backlightImpulseDuty);
+    }
+}
+
 extern std::shared_ptr<Tca8418> tca8418;
 std::shared_ptr<tt::hal::keyboard::KeyboardDevice> createKeyboard() {
     keyboardMsg = xQueueCreate(20, sizeof(char));

Boards/LilygoTLoraPager/Source/hal/TpagerKeyboard.h

@@ -5,6 +5,8 @@
 
 #include <Tca8418.h>
 #include <driver/pulse_cnt.h>
+#include <driver/ledc.h>
+#include <driver/gpio.h>
 
 #include <Tactility/Timer.h>
 
@@ -15,11 +17,20 @@ private:
     lv_indev_t* _Nullable kbHandle = nullptr;
     lv_indev_t* _Nullable encHandle = nullptr;
     pcnt_unit_handle_t encPcntUnit = nullptr;
+    gpio_num_t backlightPin = GPIO_NUM_NC;
+    ledc_timer_t backlightTimer;
+    ledc_channel_t backlightChannel;
+    bool backlightOkay = false;
+    int backlightImpulseDuty = 0;
+
     std::shared_ptr<Tca8418> keypad;
     std::unique_ptr<tt::Timer> inputTimer;
+    std::unique_ptr<tt::Timer> backlightImpulseTimer;
 
     void initEncoder(void);
+    bool initBacklight(gpio_num_t pin, uint32_t frequencyHz, ledc_timer_t timer, ledc_channel_t channel);
     void processKeyboard();
+    void processBacklightImpuse();
 
 public:
     TpagerKeyboard(std::shared_ptr<Tca8418> tca) : keypad(std::move(tca)) {}
@@ -34,6 +45,8 @@ public:
     lv_indev_t* _Nullable getLvglIndev() override { return kbHandle; }
 
     int getEncoderPulses();
+    bool setBacklightDuty(uint8_t duty);
+    void makeBacklightImpulse();
 };
 
 std::shared_ptr<tt::hal::keyboard::KeyboardDevice> createKeyboard();