Part 2: Input

src/main.c

@@ -1,16 +1,33 @@
+#include "odroid/input.h"
+#include <esp_log.h>
 #include <freertos/FreeRTOS.h>
 #include <freertos/task.h>
-#include <stdio.h>
+
+
+static const char* LOG_TAG = "Main";
 
 
 void app_main(void)
 {
+	Odroid_InitializeInput();
+
+	ESP_LOGI(LOG_TAG, "Odroid initialization complete - entering main loop");
+
 	for (;;)
 	{
-		printf("Hello World!\n");
-		vTaskDelay(1000 / portTICK_PERIOD_MS);
+		Odroid_Input input = Odroid_PollInput();
+
+		printf(
+			"\ra: %d  b: %d  start: %d  select: %d  vol: %d  menu: %d  up: %d  down: %d  left: %d  right: %d  ",
+			input.a, input.b, input.start, input.select, input.volume, input.menu,
+			input.up, input.down, input.left, input.right);
+
+		fflush(stdout);
+
+		vTaskDelay(250 / portTICK_PERIOD_MS);
 	}
 
 	// Should never get here
 	esp_restart();
 }
+

src/odroid/input.c

@@ -0,0 +1,99 @@
+#include "input.h"
+#include <driver/adc.h>
+#include <driver/gpio.h>
+#include <esp_log.h>
+#include <soc/adc_channel.h>
+
+
+static const char* LOG_TAG = "OdroidInput";
+
+static const gpio_num_t BUTTON_PIN_A = GPIO_NUM_32;
+static const gpio_num_t BUTTON_PIN_B = GPIO_NUM_33;
+static const gpio_num_t BUTTON_PIN_START = GPIO_NUM_39;
+static const gpio_num_t BUTTON_PIN_SELECT = GPIO_NUM_27;
+static const gpio_num_t BUTTON_PIN_VOLUME = GPIO_NUM_0;
+static const gpio_num_t BUTTON_PIN_MENU = GPIO_NUM_13;
+static const adc1_channel_t DPAD_PIN_X_AXIS = ADC1_GPIO34_CHANNEL;
+static const adc1_channel_t DPAD_PIN_Y_AXIS = ADC1_GPIO35_CHANNEL;
+
+
+void Odroid_InitializeInput()
+{
+	// Configure digital buttons
+	{
+		gpio_config_t gpioConfig = {};
+
+		gpioConfig.mode = GPIO_MODE_INPUT;
+		gpioConfig.pull_up_en = GPIO_PULLUP_ENABLE;
+		gpioConfig.pin_bit_mask =
+			  (1ULL << BUTTON_PIN_A)
+			| (1ULL << BUTTON_PIN_B)
+			| (1ULL << BUTTON_PIN_START)
+			| (1ULL << BUTTON_PIN_SELECT)
+			| (1ULL << BUTTON_PIN_VOLUME)
+			| (1ULL << BUTTON_PIN_MENU);
+
+		ESP_ERROR_CHECK(gpio_config(&gpioConfig));
+
+		ESP_LOGI(LOG_TAG, "Buttons initialized");
+	}
+
+	// Configure analog d-pad
+	{
+		ESP_ERROR_CHECK(adc1_config_width(ADC_WIDTH_BIT_12));
+		ESP_ERROR_CHECK(adc1_config_channel_atten(DPAD_PIN_X_AXIS,ADC_ATTEN_DB_11));
+		ESP_ERROR_CHECK(adc1_config_channel_atten(DPAD_PIN_Y_AXIS,ADC_ATTEN_DB_11));
+
+		ESP_LOGI(LOG_TAG, "D-pad initialized");
+	}
+}
+
+Odroid_Input Odroid_PollInput(void)
+{
+	Odroid_Input input = {};
+
+
+	const uint32_t ADC_HIGH_LEVEL = 3072; // 75% of 12-bit (4096) range
+	const uint32_t ADC_LOW_LEVEL = 1024; // 25% of 12-bit (4096) range
+
+
+	{
+		uint32_t dpadX = adc1_get_raw(DPAD_PIN_X_AXIS);
+
+		if (dpadX > ADC_HIGH_LEVEL)
+		{
+			input.left = 1;
+		}
+		else if (dpadX > ADC_LOW_LEVEL)
+		{
+			input.right = 1;
+		}
+	}
+
+
+	{
+		uint32_t dpadY = adc1_get_raw(DPAD_PIN_Y_AXIS);
+
+		if (dpadY > ADC_HIGH_LEVEL)
+		{
+			input.up = 1;
+		}
+		else if (dpadY > ADC_LOW_LEVEL)
+		{
+			input.down = 1;
+		}
+	}
+
+
+	// Buttons are pulled up so must invert
+	input.a = !gpio_get_level(BUTTON_PIN_A);
+	input.b = !gpio_get_level(BUTTON_PIN_B);
+	input.select = !gpio_get_level(BUTTON_PIN_SELECT);
+	input.start = !gpio_get_level(BUTTON_PIN_START);
+	input.menu = !gpio_get_level(BUTTON_PIN_MENU);
+	input.volume = !gpio_get_level(BUTTON_PIN_VOLUME);
+
+
+	return input;
+}
+

src/odroid/input.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include <stdint.h>
+
+
+typedef struct
+{
+	uint16_t a : 1;
+	uint16_t b : 1;
+	uint16_t volume : 1;
+	uint16_t menu : 1;
+	uint16_t select : 1;
+	uint16_t start : 1;
+	uint16_t left : 1;
+	uint16_t right : 1;
+	uint16_t up : 1;
+	uint16_t down : 1;
+} Odroid_Input;
+
+void Odroid_InitializeInput(void);
+Odroid_Input Odroid_PollInput(void);
+