Merge pull request #32 from stevenewald/echavemann/capsense-driver

Capacitive Touch Controller

Author: stevenewald

include/drivers/captouch_controller.hpp

@@ -0,0 +1,46 @@
+#pragma once
+
+#include "drivers/driver_enums.hpp"
+#include "drivers/gpio_pin.hpp"
+#include "drivers/gpio_pin_event.hpp"
+#include "microbit_v2.h"
+#include "nrf_gpio.h"
+#include "scheduler/user_callback_storage.hpp"
+#include "util.hpp"
+
+namespace edge::drivers {
+
+class CapsenseController {
+    GPIOPin touch_logo{TOUCH_LOGO, GPIOConfiguration::IN_NORES};
+
+    UserCallbackStorage subscriptions;
+
+    bool touched;
+
+    bool prev_touched;
+
+    uint32_t time_test_started;
+
+    GPIOPinEvent event;
+
+    CapsenseController();
+    ~CapsenseController() = default;
+
+public:
+    CapsenseController(const CapsenseController&) = delete;
+    CapsenseController(CapsenseController&&) = delete;
+    CapsenseController& operator=(const CapsenseController&) = delete;
+    CapsenseController& operator=(CapsenseController&&) = delete;
+
+    static CapsenseController& get();
+
+    void subscribe_captouch_press(ProcessCallbackPtr callback, uint8_t process_id);
+
+    bool get_captouch_pressed();
+
+    void handle_gpio_interrupt(nrf_gpio_pin_sense_t sense, int pin);
+
+    void start_capacitive_test();
+};
+
+} // namespace edge::drivers

include/drivers/driver_enums.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "hal/hal_enums.hpp"
 #include "util.hpp"
 
 namespace edge::drivers {
@@ -9,9 +10,14 @@ enum class DriverCommand {
     BUTTONS = 2,
     TERMINAL_OUTPUT = 3,
     TIMER_CANCEL = 4,
+    CAPTOUCH = 5,
 };
 
-enum class DriverSubscribe { NOTIFY_BUTTON_PRESS = 0, TIMER_START = 1 };
+enum class DriverSubscribe {
+    NOTIFY_BUTTON_PRESS = 0,
+    TIMER_START = 1,
+    NOTIFY_CAPTOUCH = 2
+};
 
 enum class GPIOConfiguration { OUT, IN_NORES, IN_PDR, IN_PUR };
 
@@ -24,4 +30,7 @@ struct subscribe_callback {
     int arg2;
 };
 
+aidan::PinPullMode to_pin_pull_mode(drivers::GPIOConfiguration config);
+drivers::ButtonState to_cap_sense_state(nrf_gpio_pin_sense_t sense);
+
 } // namespace edge::drivers

include/drivers/gpio_pin_event.hpp

@@ -14,9 +14,8 @@ class GPIOPinEvent {
     ) :
         pin(pin)
     {
-        // TODO: add resistance
         aidan::GPIOEventController::get().set_gpio_callback(
-            pin, aidan::PinPullMode::PUR, callback
+            pin, to_pin_pull_mode(resistance), callback
         );
     }
 

include/userlib/syscalls.hpp

@@ -21,6 +21,10 @@ void get_button_pressed(
     void (*callback)(drivers::ButtonType, drivers::ButtonState)
 );
 
+bool get_captouch_pressed();
+
+void subscribe_captouch_pressed(void (*callback)(drivers::ButtonState));
+
 void send_ipc(const char* name, uint32_t message);
 
 void subscribe_ipc(const char* name, void (*callback)(int message));

src/drivers/captouch_controller.cpp

@@ -0,0 +1,62 @@
+#include "drivers/captouch_controller.hpp"
+
+#include "config.hpp"
+#include "microbit_v2.h"
+#include "nrf_gpio.h"
+
+namespace edge::drivers {
+
+CapsenseController::CapsenseController() :
+    touched(false), prev_touched(false),
+    event{
+        TOUCH_LOGO, GPIOConfiguration::IN_NORES,
+        aidan::GPIOEventController::GPIOEventCallback::create<
+            CapsenseController, &CapsenseController::handle_gpio_interrupt>(*this)
+    }
+{
+    touch_logo.clear();
+    nrf_gpio_cfg(
+        TOUCH_LOGO, NRF_GPIO_PIN_DIR_OUTPUT, NRF_GPIO_PIN_INPUT_DISCONNECT,
+        NRF_GPIO_PIN_NOPULL, NRF_GPIO_PIN_S0S1, NRF_GPIO_PIN_NOSENSE
+    );
+};
+
+CapsenseController& CapsenseController::get()
+{
+    static CapsenseController capsenseController;
+    return capsenseController;
+}
+
+void CapsenseController::subscribe_captouch_press(
+    ProcessCallbackPtr callback, uint8_t process_id
+)
+{
+    subscriptions.set_callback(process_id, callback);
+}
+
+bool CapsenseController::get_captouch_pressed()
+{
+    return touched;
+}
+
+void CapsenseController::handle_gpio_interrupt(nrf_gpio_pin_sense_t sense, int pin)
+{
+    if (sense == NRF_GPIO_PIN_SENSE_LOW) {
+        touched = true;
+    }
+    else if (sense == NRF_GPIO_PIN_SENSE_HIGH) {
+        touched = false;
+    }
+    if ((prev_touched != touched)) {
+        for (int process_id = 0; process_id < MAX_PROCESSES; ++process_id) {
+            if (subscriptions.has_callback(process_id)) {
+                subscriptions.call_callback(
+                    process_id, static_cast<int>(to_cap_sense_state(sense))
+                );
+            }
+        }
+    }
+    prev_touched = touched;
+}
+
+} // namespace edge::drivers

src/drivers/driver_commands.cpp

@@ -1,6 +1,7 @@
 #include "drivers/driver_commands.hpp"
 
 #include "drivers/button_driver.hpp"
+#include "drivers/captouch_controller.hpp"
 #include "drivers/driver_enums.hpp"
 #include "drivers/led_matrix_controller.hpp"
 #include "drivers/virtual_timer_controller.hpp"
@@ -25,6 +26,8 @@ etl::optional<int> handle_command(DriverCommand type, int arg1, int arg2, int ar
             return ButtonController::get().get_button_pressed(
                 static_cast<ButtonType>(arg1)
             );
+        case DriverCommand::CAPTOUCH:
+            return CapsenseController::get().get_captouch_pressed();
         case DriverCommand::TIMER_CANCEL:
             VirtualTimerController::get().virtual_timer_cancel(
                 static_cast<uint32_t>(arg1)
@@ -49,6 +52,9 @@ etl::optional<int> handle_subscribe(
             return VirtualTimerController::get().virtual_timer_start(
                 static_cast<uint32_t>(arg1), callback, 0, arg2
             );
+        case DriverSubscribe::NOTIFY_CAPTOUCH:
+            CapsenseController::get().subscribe_captouch_press(callback, process_id);
+            break;
     }
     return etl::nullopt;
 }

src/drivers/driver_enums.cpp

@@ -0,0 +1,34 @@
+#include "drivers/driver_enums.hpp"
+
+#include "hal/hal_enums.hpp"
+#include "util.hpp"
+
+namespace edge::drivers {
+aidan::PinPullMode to_pin_pull_mode(GPIOConfiguration configuration)
+{
+    switch (configuration) {
+        case GPIOConfiguration::IN_NORES:
+            return aidan::PinPullMode::NONE;
+        case GPIOConfiguration::IN_PDR:
+            return aidan::PinPullMode::PDR;
+        case GPIOConfiguration::IN_PUR:
+            return aidan::PinPullMode::PUR;
+        default:
+            panic("Unexpected GPIO Configuration conversion to PinPullMode.");
+    }
+}
+
+drivers::ButtonState to_cap_sense_state(nrf_gpio_pin_sense_t sense)
+{
+    if (sense == NRF_GPIO_PIN_SENSE_LOW) {
+        return drivers::ButtonState::DOWN;
+    }
+    else if (sense == NRF_GPIO_PIN_SENSE_HIGH) {
+        return drivers::ButtonState::UP;
+    }
+    else {
+        panic("Unexpected nrf_gpio_pin_sense");
+    }
+}
+
+} // namespace edge::drivers

src/entrypoint.cpp

@@ -9,13 +9,15 @@
 extern void ipc_part1(void);
 extern void ipc_part2(void);
 extern void exception_task(void);
+extern void captouch_task(void);
 
 int main(void)
 {
     printf("Starting EdgeOS\n");
 
     edge::FaultHandler::get();
 
+    edge::scheduler.add_task(captouch_task);
     edge::scheduler.add_task(exception_task);
 
     edge::scheduler.add_task(ipc_part1);

src/user_programs/user_program_captouch.cpp

@@ -0,0 +1,28 @@
+#include "drivers/driver_enums.hpp"
+#include "hal/gpio_wrapper.hpp"
+#include "nrf_delay.h"
+#include "userlib/syscalls.hpp"
+
+void callback(edge::drivers::ButtonState a)
+{
+    if (a == edge::drivers::ButtonState::UP) {
+        edge::userlib::debug_print("CALLBACK: Finger lifted.\n");
+    }
+    else {
+        edge::userlib::debug_print("CALLBACK: Finger pressed.\n");
+    }
+}
+
+void captouch_task(void)
+{
+    edge::userlib::subscribe_captouch_pressed(callback);
+    while (1) {
+        if (edge::userlib::get_captouch_pressed()) {
+            // edge::userlib::debug_print("pressed\n");
+        }
+        else {
+            // edge::userlib::debug_print("not pressed\n");
+        }
+        edge::userlib::yield();
+    }
+}

src/user_programs/user_program_exception.cpp

@@ -6,14 +6,14 @@ void callback(uint32_t id)
 {
     static bool b = false;
     edge::userlib::set_led(2, 2, b);
-	b=!b;
+    b = !b;
 }
 
 void callback2(uint32_t id)
 {
     static bool b = false;
     edge::userlib::set_led(2, 2, b);
-	b=!b;
+    b = !b;
 }
 
 void exception_task(void)