5 files changed, 536 insertions, 0 deletions
diff --git a/src/gymnasiearbete.cpp b/src/gymnasiearbete.cpp
new file mode 100644
index 0000000..0e1adb5
--- /dev/null
+++ b/src/gymnasiearbete.cpp
@@ -0,0 +1,69 @@
+#include "secrets.hpp"
+#include "wifi_module.hpp"
+
+#include <Arduino.h>
+#include <SoftwareSerial.h>
+#include <string.h>
+
+constexpr auto BAUDRATE = 9600U;
+
+constexpr auto NETWORK_MODULE_RX_PIN = 3;
+constexpr auto NETWORK_MODULE_TX_PIN = 2;
+
+auto wifi_module = WiFiModule(NETWORK_MODULE_RX_PIN, NETWORK_MODULE_TX_PIN);
+
+void setup()
+{
+	Serial.begin(BAUDRATE);
+
+	pinMode(NETWORK_MODULE_RX_PIN, INPUT);
+	pinMode(NETWORK_MODULE_TX_PIN, OUTPUT);
+
+	wifi_module.begin(BAUDRATE);
+
+	wifi_module.reset();
+
+	delay(1000);
+
+	auto wifi_module_connected = wifi_module.test();
+
+	Serial.print("Wifi module connected: ");
+	Serial.println(wifi_module_connected ? "Yes" : "No");
+
+	if (!wifi_module_connected)
+	{
+		while (true)
+		{
+		}
+	}
+
+	wifi_module.set_echo_enabled(false);
+
+	delay(1000);
+
+	const auto wifi_connect_success = wifi_module.connect(WIFI_SSID, WIFI_PASSWORD);
+
+	if (wifi_connect_success)
+	{
+		Serial.print("Connected to wifi network '");
+		Serial.print(WIFI_SSID);
+		Serial.println("' successfully");
+	}
+	else
+	{
+		Serial.print("Failed to connect to wifi network '");
+		Serial.print(WIFI_SSID);
+		Serial.println("'");
+	}
+
+	wifi_module.set_wifi_mode(WifiMode::Station);
+
+	delay(3000);
+
+	char local_ip[MAX_NETWORK_MODULE_RESPONSE_LENGTH] = "";
+
+	Serial.print("IP address: ");
+	Serial.println(wifi_module.get_local_ip(local_ip));
+}
+
+void loop() {}
diff --git a/src/util.cpp b/src/util.cpp
new file mode 100644
index 0000000..f587781
--- /dev/null
+++ b/src/util.cpp
@@ -0,0 +1,35 @@
+#include "util.hpp"
+
+namespace util
+{
+
+bool str_ends_with(const char *str, const char *other_str) noexcept
+{
+	if (str == nullptr || other_str == nullptr)
+	{
+		return false;
+	}
+
+	auto str_length = strlen(str);
+	auto other_str_length = strlen(other_str);
+
+	if (other_str_length > str_length)
+	{
+		return false;
+	}
+
+	return strncmp(str + str_length - other_str_length, other_str, other_str_length) == 0;
+}
+
+void substr(const char *str, const char *end, char *dest) noexcept
+{
+	auto *dest_head = dest;
+
+	for (const char *char_ptr = str; char_ptr + 1 != end; ++char_ptr)
+	{
+		*dest_head = *char_ptr;
+		dest_head++;
+	}
+}
+
+} // namespace util
diff --git a/src/util.hpp b/src/util.hpp
new file mode 100644
index 0000000..d6f7f1c
--- /dev/null
+++ b/src/util.hpp
@@ -0,0 +1,27 @@
+#pragma once
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+
+namespace util
+{
+
+template <typename Type>
+Type *malloc(size_t size) noexcept
+{
+	return static_cast<Type *>(::malloc(size));
+}
+
+bool str_ends_with(const char *str, const char *other_str) noexcept;
+
+/**
+ * Extracts a portion of a string.
+ *
+ * @param str The target string.
+ * @param end A pointer to a place inside the target string.
+ * @param dest Output buffer.
+ */
+void substr(const char *str, const char *end, char *dest) noexcept;
+
+} // namespace util
diff --git a/src/wifi_module.cpp b/src/wifi_module.cpp
new file mode 100644
index 0000000..2e25dc9
--- /dev/null
+++ b/src/wifi_module.cpp
@@ -0,0 +1,312 @@
+#include "wifi_module.hpp"
+
+#include "util.hpp"
+
+#include <Arduino.h>
+#include <string.h>
+
+WiFiModule::WiFiModule(uint8_t receive_pin, uint8_t transmit_pin) noexcept
+	: _serial(receive_pin, transmit_pin)
+{
+}
+
+void WiFiModule::begin(size_t baudrate) noexcept
+{
+	_serial.begin(baudrate);
+}
+
+int WiFiModule::get_available() noexcept
+{
+	return _serial.available();
+}
+
+void WiFiModule::reset() noexcept
+{
+	_send_serial("AT+RST");
+
+	char response[MAX_NETWORK_MODULE_RESPONSE_LENGTH] = "";
+
+	const auto response_status = _read(2000U, response);
+
+	Serial.println(
+		response_status == ResponseStatus::OK ? "Reset wifi module"
+											  : "Failed to reset wifi module"
+	);
+}
+
+bool WiFiModule::connect(const char *ssid, const char *password) noexcept
+{
+	const char cmd[] = "AT+CWJAP";
+
+	auto command_length = strlen(cmd) + strlen(ssid) + strlen(password) + 6U + 1U;
+
+	auto *command = util::malloc<char>(command_length);
+
+	if (command == nullptr)
+	{
+		Serial.println("Memory allocation failed for creating full connection command");
+		return false;
+	}
+
+	snprintf(command, command_length, "%s=\"%s\",\"%s\"", cmd, ssid, password);
+
+	const auto send_success = _send_serial(command);
+
+	if (!send_success)
+	{
+		Serial.println("Failed to send connection command");
+		return false;
+	}
+
+	free(command);
+
+	char response[MAX_NETWORK_MODULE_RESPONSE_LENGTH] = "";
+
+	const auto response_status = _read(20000U, response);
+
+	if (response_status != ResponseStatus::OK)
+	{
+		Serial.print("Connection command responded with status ");
+		Serial.println(response_status);
+		return false;
+	}
+
+	return true;
+}
+
+void WiFiModule::set_wifi_mode(WifiMode wifi_mode) noexcept
+{
+	const char cmd[] = "AT+CWMODE_CUR";
+
+	auto command_length = strlen(cmd) + 2U + 1U;
+
+	auto *command = util::malloc<char>(command_length);
+
+	snprintf(command, command_length, "%s=%u", cmd, static_cast<int>(wifi_mode));
+
+	_send_serial(command);
+
+	free(command);
+
+	char response[MAX_NETWORK_MODULE_RESPONSE_LENGTH] = "";
+
+	_read(1500U, response);
+}
+
+void WiFiModule::set_multiple_connections_enabled(bool is_enabled) noexcept
+{
+	const char cmd[] = "AT+CIPMUX";
+
+	auto command_length = strlen(cmd) + 2U + 1U;
+
+	auto *command = util::malloc<char>(command_length);
+
+	snprintf(command, command_length, "%s=%u", cmd, is_enabled ? 1U : 0U);
+
+	_send_serial(command);
+
+	free(command);
+
+	char response[MAX_NETWORK_MODULE_RESPONSE_LENGTH] = "";
+
+	_read(1500U, response);
+
+	// Serial.println(response);
+}
+
+void WiFiModule::set_echo_enabled(bool is_enabled) noexcept
+{
+	const char cmd[] = "ATE";
+
+	auto command_length = strlen(cmd) + 1U + 1U;
+
+	auto *command = util::malloc<char>(command_length);
+
+	snprintf(command, command_length, "%s%u", cmd, is_enabled ? 1U : 0U);
+
+	_send_serial(command);
+
+	free(command);
+
+	char response[MAX_NETWORK_MODULE_RESPONSE_LENGTH] = "";
+
+	const auto response_status = _read(1500U, response);
+
+	if (response_status == ResponseStatus::OK)
+	{
+		Serial.print("Turned ");
+		Serial.print(is_enabled ? "on" : "off");
+		Serial.println(" AT commands echo");
+	}
+	else
+	{
+		Serial.print("Failed to turn ");
+		Serial.print(is_enabled ? "on" : "off");
+		Serial.println(" AT commands echo");
+	}
+}
+
+void WiFiModule::create_tcp_server(size_t port) noexcept
+{
+	const auto cmd = "AT+CIPSERVER";
+
+	auto command_length = strlen(cmd) + 7U + 1U;
+
+	auto *command = util::malloc<char>(command_length);
+
+	snprintf(command, command_length, "%s=1,%u", cmd, port);
+
+	_send_serial(command);
+
+	free(command);
+
+	char response[MAX_NETWORK_MODULE_RESPONSE_LENGTH] = "";
+
+	_read(1500U, response);
+
+	// Serial.println(response);
+}
+
+bool WiFiModule::test() noexcept
+{
+	const auto send_success = _send_serial("AT");
+
+	if (!send_success)
+	{
+		return false;
+	}
+
+	char response[MAX_NETWORK_MODULE_RESPONSE_LENGTH] = "";
+
+	const auto response_status = _read(5000U, response);
+
+	if (response_status == ResponseStatus::TIMEOUT)
+	{
+		return false;
+	}
+
+	return strcmp(response, "") != 0;
+}
+
+const char *WiFiModule::get_local_ip(char *local_ip_out) noexcept
+{
+	const auto command = "AT+CIFSR";
+
+	const auto send_success = _send_serial(command);
+
+	if (!send_success)
+	{
+		return local_ip_out;
+	}
+
+	auto *buf = util::malloc<char>(strlen(local_ip_out));
+
+	if (buf == nullptr)
+	{
+		strcpy(local_ip_out, "Memory allocation failure");
+		return local_ip_out;
+	}
+
+	const auto response_status = _read(10000U, buf);
+
+	if (response_status != ResponseStatus::OK)
+	{
+		free(buf);
+
+		sprintf(
+			local_ip_out,
+			"Response status was not OK. Was %d",
+			static_cast<int>(response_status)
+		);
+
+		return local_ip_out;
+	}
+
+	const auto *local_ip_end = strstr(buf, "\r\n+CIFSR:STAMAC");
+
+	if (local_ip_end == nullptr)
+	{
+		free(buf);
+		strcpy(local_ip_out, "Response parsing error");
+		return local_ip_out;
+	}
+
+	const auto staip_title_length = 16U; // The length of '+CIFSR:STAIP,"'
+
+	util::substr(buf + staip_title_length, local_ip_end, local_ip_out);
+
+	free(buf);
+
+	return local_ip_out;
+}
+
+bool WiFiModule::_send_serial(const char *command) noexcept
+{
+	auto full_command_length = strlen(command) + 2U + 1U;
+
+	auto *full_command = util::malloc<char>(full_command_length);
+
+	if (full_command == nullptr)
+	{
+		return false;
+	}
+
+	snprintf(full_command, full_command_length, "%s\r\n", command);
+
+	_serial.print(full_command);
+
+	// Serial.print("Sent command: ");
+	// Serial.println(full_command);
+
+	free(full_command);
+
+	return true;
+}
+
+ResponseStatus WiFiModule::_read(uint64_t timeout, char *response_out) noexcept
+{
+	const auto start_time = millis();
+
+	bool has_end = false;
+	auto status = ResponseStatus::TIMEOUT;
+
+	// auto *response_out_head = response_out;
+
+	while (!has_end && (start_time + timeout) > millis())
+	{
+		while (_serial.available() != 0)
+		{
+			char character = _read_byte();
+
+			strncat(response_out, &character, 1U);
+
+			// *response_out_head = character;
+			// response_out_head++;
+
+			if (util::str_ends_with(response_out, "OK"))
+			{
+				status = ResponseStatus::OK;
+				has_end = true;
+			}
+
+			if (util::str_ends_with(response_out, "ERROR"))
+			{
+				status = ResponseStatus::ERROR;
+				has_end = true;
+			}
+
+			if (util::str_ends_with(response_out, "FAIL"))
+			{
+				status = ResponseStatus::FAIL;
+				has_end = true;
+			}
+		}
+	}
+
+	return status;
+}
+
+char WiFiModule::_read_byte() noexcept
+{
+	return static_cast<char>(_serial.read());
+}
diff --git a/src/wifi_module.hpp b/src/wifi_module.hpp
new file mode 100644
index 0000000..5a4148c
--- /dev/null
+++ b/src/wifi_module.hpp
@@ -0,0 +1,93 @@
+#pragma once
+
+#include <SoftwareSerial.h>
+#include <stddef.h>
+#include <stdint.h>
+
+constexpr auto MAX_NETWORK_MODULE_RESPONSE_LENGTH = 128U;
+
+enum WifiMode
+{
+	Station = 1,
+	SoftAP = 2,
+	SoftAPAndStation = 3
+};
+
+enum ResponseStatus
+{
+	OK,
+	FAIL,
+	ERROR,
+	TIMEOUT
+};
+
+class WiFiModule
+{
+public:
+	WiFiModule(uint8_t receive_pin, uint8_t transmit_pin) noexcept;
+
+	void begin(size_t baudrate) noexcept;
+
+	int get_available() noexcept;
+
+	void reset() noexcept;
+
+	/**
+	 * Connects to a wifi network.
+	 *
+	 * @param ssid The service set identifier of a wifi network.
+	 * @param password The wifi network password.
+	 *
+	 * @returns Whether or not it succeeded.
+	 */
+	bool connect(const char *ssid, const char *password) noexcept;
+
+	void set_wifi_mode(WifiMode wifi_mode) noexcept;
+
+	void set_multiple_connections_enabled(bool is_enabled) noexcept;
+
+	void set_echo_enabled(bool is_enabled) noexcept;
+
+	void create_tcp_server(size_t port) noexcept;
+
+	/**
+	 * Tests the connection to the wifi module.
+	 *
+	 * @returns Whether or not the test succeeded.
+	 */
+	bool test() noexcept;
+
+	/**
+	 * Gets local IP address of the wifi module.
+	 *
+	 * @param local_ip_out Local IP output buffer.
+	 *
+	 * @returns A pointer to the local IP output buffer.
+	 */
+	const char *get_local_ip(char *local_ip_out) noexcept;
+
+private:
+	SoftwareSerial _serial;
+
+	/**
+	 * Sends a command to the wifi module.
+	 *
+	 * @param command A command without the "AT+" in the beginning.
+	 *
+	 * @returns Whether or not it succeeded.
+	 */
+	bool _send_serial(const char *command) noexcept;
+
+	/**
+	 * Reads from the wifi module until it responds with a status.
+	 *
+	 * @param timeout Timeout in milliseconds.
+	 * @param response_out Response output buffer.
+	 *
+	 * @returns The response status.
+	 *
+	 */
+	ResponseStatus _read(uint64_t timeout, char *response_out) noexcept;
+
+	char _read_byte() noexcept;
+};