added chapter 3 and refactor of chapter 1 and chapter 2

0x0001_hello-world/.gitignore

@@ -1,5 +1,7 @@
-.pio
-.vscode/.browse.c_cpp.db*
-.vscode/c_cpp_properties.json
-.vscode/launch.json
-.vscode/ipch
+.idea
+.vscode
+_deps
+cmake-*
+build
+.DS_Store
+*.pdf

0x0001_hello-world/.vscode/extensions.json

@@ -1,10 +1,9 @@
 {
-    // See http://go.microsoft.com/fwlink/?LinkId=827846
-    // for the documentation about the extensions.json format
-    "recommendations": [
-        "platformio.platformio-ide"
-    ],
-    "unwantedRecommendations": [
-        "ms-vscode.cpptools-extension-pack"
-    ]
+  "recommendations": [
+    "marus25.cortex-debug",
+    "ms-vscode.cmake-tools",
+    "ms-vscode.cpptools",
+    "ms-vscode.cpptools-extension-pack",
+    "ms-vscode.vscode-serial-monitor"
+  ]
 }

0x0001_hello-world/.vscode/settings.json

@@ -1,5 +1,30 @@
 {
+    // These settings tweaks to the cmake plugin will ensure
+    // that you debug using cortex-debug instead of trying to launch
+    // a Pico binary on the host
+    "cmake.statusbar.advanced": {
+        "debug": {
+            "visibility": "hidden"
+        },
+        "launch": {
+            "visibility": "hidden"
+        },
+        "build": {
+            "visibility": "hidden"
+        },
+        "buildTarget": {
+            "visibility": "hidden"
+        }
+    },
+    "cmake.buildBeforeRun": true,
+    "cmake.configureOnOpen": true,
+    "cmake.configureSettings": {
+      "CMAKE_MODULE_PATH": "${env:PICO_INSTALL_PATH}/pico-sdk-tools"
+    },
+    "cmake.generator": "Ninja",
+    "C_Cpp.default.configurationProvider": "ms-vscode.cmake-tools",
+    "C_Cpp.errorSquiggles": "enabled",
     "files.associations": {
-        "stm32f4xx.h": "c"
+        "stdlib.h": "c"
     }
-}
+}

0x0001_hello-world/CMakeLists.txt

@@ -0,0 +1,57 @@
+cmake_minimum_required(VERSION 3.13)
+
+set(PICO_BOARD pico_w)
+
+include(pico_sdk_import.cmake)
+
+project(0x0001_hello-world C CXX ASM)
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_CXX_STANDARD 17)
+
+pico_sdk_init()
+
+if (PICO_CYW43_SUPPORTED) # set by PICO_BOARD=pico_w
+    if (NOT TARGET pico_cyw43_arch)
+        message("Skipping Pico W examples as support is not available")
+    else()
+
+        if (DEFINED ENV{WIFI_SSID} AND (NOT WIFI_SSID))
+            set(WIFI_SSID $ENV{WIFI_SSID})
+            message("Using WIFI_SSID from environment ('${WIFI_SSID}')")
+        endif()
+
+        if (DEFINED ENV{WIFI_PASSWORD} AND (NOT WIFI_PASSWORD))
+            set(WIFI_PASSWORD $ENV{WIFI_PASSWORD})
+            message("Using WIFI_PASSWORD from environment")
+        endif()
+
+        set(WIFI_SSID "${WIFI_SSID}" CACHE INTERNAL "WiFi SSID for examples")
+        set(WIFI_PASSWORD "${WIFI_PASSWORD}" CACHE INTERNAL "WiFi password for examples")
+    endif()
+endif()
+
+set(WIFI_SSID "${WIFI_SSID}" CACHE INTERNAL "WiFi SSID")
+set(WIFI_PASSWORD "${WIFI_PASSWORD}" CACHE INTERNAL "WiFi PASSWORD")
+
+add_executable(0x0001_hello-world
+        main.c
+        )
+target_compile_definitions(0x0001_hello-world PRIVATE
+        WIFI_SSID=\"${WIFI_SSID}\"
+        WIFI_PASSWORD=\"${WIFI_PASSWORD}\"
+        )
+target_include_directories(0x0001_hello-world PRIVATE
+        ${CMAKE_CURRENT_LIST_DIR}
+        ${CMAKE_CURRENT_LIST_DIR}/.. # for our common lwipopts
+        )
+target_link_libraries(0x0001_hello-world
+        pico_cyw43_arch_lwip_threadsafe_background
+        pico_lwip_mbedtls
+        pico_mbedtls
+        pico_stdlib
+        )
+
+pico_enable_stdio_usb(0x0001_hello-world 1)
+pico_enable_stdio_uart(0x0001_hello-world 1)
+
+pico_add_extra_outputs(0x0001_hello-world)

0x0001_hello-world/include/README

@@ -1,39 +0,0 @@
-
-This directory is intended for project header files.
-
-A header file is a file containing C declarations and macro definitions
-to be shared between several project source files. You request the use of a
-header file in your project source file (C, C++, etc) located in `src` folder
-by including it, with the C preprocessing directive `#include'.
-
-```src/main.c
-
-#include "header.h"
-
-int main (void)
-{
- ...
-}
-```
-
-Including a header file produces the same results as copying the header file
-into each source file that needs it. Such copying would be time-consuming
-and error-prone. With a header file, the related declarations appear
-in only one place. If they need to be changed, they can be changed in one
-place, and programs that include the header file will automatically use the
-new version when next recompiled. The header file eliminates the labor of
-finding and changing all the copies as well as the risk that a failure to
-find one copy will result in inconsistencies within a program.
-
-In C, the usual convention is to give header files names that end with `.h'.
-It is most portable to use only letters, digits, dashes, and underscores in
-header file names, and at most one dot.
-
-Read more about using header files in official GCC documentation:
-
-* Include Syntax
-* Include Operation
-* Once-Only Headers
-* Computed Includes
-
-https://gcc.gnu.org/onlinedocs/cpp/Header-Files.html

0x0001_hello-world/include/usart.h

@@ -1,87 +0,0 @@
-/**
- * FILE: usart.h
- *
- * DESCRIPTION: This file contains the usart function definitions utilizing the STM32F401CC6 microcontroller.
- *
- * AUTHOR: Kevin Thomas
- * DATE: October 6, 2023
- */
-
-#ifndef USART_H
-#define USART_H
-
-#include <stdint.h>
-
-#include "stm32f4xx.h"
-
-#define DEFAULT_CLK_SPEED 16000000U
-
-extern int __io_putchar(int ch) __attribute__((weak));
-
-/**
- * @brief  Sets the baud rate for a given USART peripheral.
- *
- *         This function calculates and sets the baud rate register (BRR) for
- *         the specified USART peripheral based on the provided peripheral clock
- *         speed and desired baud rate.
- *
- * @param  USARTx: Pointer to the USART peripheral (e.g., USART1, USART2, etc.).
- * @param  periph_clk: The frequency of the peripheral clock in Hertz.
- * @param  baud_rate: The desired baud rate for communication.
- * @retval None
- */
-static void set_baud_rate(USART_TypeDef *USARTx,  uint32_t periph_clk, uint32_t baud_rate);
-
-/**
- * @brief  Initializes USART2 for transmission on PA2 pin and receive on PA3 pin.
- *
- *         This function configures the necessary settings for USART2 to enable
- *         transmission on pin PA2 and receive on PA3 pin. It includes configuring 
- *         GPIO, setting alternate function mode, configuring the USART clock, setting the
- *         baud rate, and enabling the transmitter.
- *
- * @param  None
- * @retval None
- */
-void usart2_init(void);
-
-/**
- * @brief  Writes a single byte to USART2 for transmission.
- *
- *         This function writes a single byte to the USART2  data
- *         register for transmission. It ensures that the data register
- *         is empty before writing the byte.
- *
- * @param  char_: The byte to be transmitted.
- * @retval None
- */
-void usart2_write_char(uint8_t char_);
-
-/**
- * @brief  Reads a single byte from USART2.
- *
- *         This function reads a single byte from the USART2 data
- *         register. It ensures that the data register is not empty
- *         before reading the byte.
- *
- * @param  None
- * @retval The byte read from the data register.
- */
-char usart2_read_char(void);
-
-/**
- * @brief  Reads a string of characters from input and stores it in the buffer.
- *
- *         This function reads characters from input and stores them in the
- *         provided buffer until either the buffer is full (reaching
- *         buffer_size - 1 characters) or a newline character is encountered.
- *         The input is null-terminated, ensuring proper string termination in
- *         the buffer.
- *
- * @param  buffer: Pointer to the buffer where the input characters are stored.
- * @param  buffer_size: The size of the buffer, including space for the null-terminator.
- * @retval None
- */
-void input(char *buffer, size_t buffer_size);
-
-#endif // USART_H

0x0001_hello-world/lib/README

@@ -1,46 +0,0 @@
-
-This directory is intended for project specific (private) libraries.
-PlatformIO will compile them to static libraries and link into executable file.
-
-The source code of each library should be placed in a an own separate directory
-("lib/your_library_name/[here are source files]").
-
-For example, see a structure of the following two libraries `Foo` and `Bar`:
-
-|--lib
-|  |
-|  |--Bar
-|  |  |--docs
-|  |  |--examples
-|  |  |--src
-|  |     |- Bar.c
-|  |     |- Bar.h
-|  |  |- library.json (optional, custom build options, etc) https://docs.platformio.org/page/librarymanager/config.html
-|  |
-|  |--Foo
-|  |  |- Foo.c
-|  |  |- Foo.h
-|  |
-|  |- README --> THIS FILE
-|
-|- platformio.ini
-|--src
-   |- main.c
-
-and a contents of `src/main.c`:
-```
-#include <Foo.h>
-#include <Bar.h>
-
-int main (void)
-{
-  ...
-}
-
-```
-
-PlatformIO Library Dependency Finder will find automatically dependent
-libraries scanning project source files.
-
-More information about PlatformIO Library Dependency Finder
-- https://docs.platformio.org/page/librarymanager/ldf.html

0x0001_hello-world/lwipopts.h

@@ -0,0 +1,18 @@
+#ifndef _LWIPOPTS_H
+#define _LWIPOPTS_H
+
+#include "lwipopts_examples_common.h"
+
+/* TCP WND must be at least 16 kb to match TLS record size
+   or you will get a warning "altcp_tls: TCP_WND is smaller than the RX decrypion buffer, connection RX might stall!" */
+#undef TCP_WND
+#define TCP_WND  16384
+
+#define LWIP_ALTCP               1
+#define LWIP_ALTCP_TLS           1
+#define LWIP_ALTCP_TLS_MBEDTLS   1
+
+#define LWIP_DEBUG 1
+#define ALTCP_MBEDTLS_DEBUG  LWIP_DBG_ON
+
+#endif

0x0001_hello-world/lwipopts_examples_common.h

@@ -0,0 +1,89 @@
+#ifndef _LWIPOPTS_EXAMPLE_COMMONH_H
+#define _LWIPOPTS_EXAMPLE_COMMONH_H
+
+// Common settings used in most of the pico_w examples
+// (see https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html for details)
+
+// allow override in some examples
+#ifndef NO_SYS
+#define NO_SYS                      1
+#endif
+// allow override in some examples
+#ifndef LWIP_SOCKET
+#define LWIP_SOCKET                 0
+#endif
+#if PICO_CYW43_ARCH_POLL
+#define MEM_LIBC_MALLOC             1
+#else
+// MEM_LIBC_MALLOC is incompatible with non polling versions
+#define MEM_LIBC_MALLOC             0
+#endif
+#define MEM_ALIGNMENT               4
+#define MEM_SIZE                    4000
+#define MEMP_NUM_TCP_SEG            32
+#define MEMP_NUM_ARP_QUEUE          10
+#define PBUF_POOL_SIZE              24
+#define LWIP_ARP                    1
+#define LWIP_ETHERNET               1
+#define LWIP_ICMP                   1
+#define LWIP_RAW                    1
+#define TCP_WND                     (8 * TCP_MSS)
+#define TCP_MSS                     1460
+#define TCP_SND_BUF                 (8 * TCP_MSS)
+#define TCP_SND_QUEUELEN            ((4 * (TCP_SND_BUF) + (TCP_MSS - 1)) / (TCP_MSS))
+#define LWIP_NETIF_STATUS_CALLBACK  1
+#define LWIP_NETIF_LINK_CALLBACK    1
+#define LWIP_NETIF_HOSTNAME         1
+#define LWIP_NETCONN                0
+#define MEM_STATS                   0
+#define SYS_STATS                   0
+#define MEMP_STATS                  0
+#define LINK_STATS                  0
+// #define ETH_PAD_SIZE                2
+#define LWIP_CHKSUM_ALGORITHM       3
+#define LWIP_DHCP                   1
+#define LWIP_IPV4                   1
+#define LWIP_TCP                    1
+#define LWIP_UDP                    1
+#define LWIP_DNS                    1
+#define LWIP_TCP_KEEPALIVE          1
+#define LWIP_NETIF_TX_SINGLE_PBUF   1
+#define DHCP_DOES_ARP_CHECK         0
+#define LWIP_DHCP_DOES_ACD_CHECK    0
+
+#ifndef NDEBUG
+#define LWIP_DEBUG                  1
+#define LWIP_STATS                  1
+#define LWIP_STATS_DISPLAY          1
+#endif
+
+#define ETHARP_DEBUG                LWIP_DBG_OFF
+#define NETIF_DEBUG                 LWIP_DBG_OFF
+#define PBUF_DEBUG                  LWIP_DBG_OFF
+#define API_LIB_DEBUG               LWIP_DBG_OFF
+#define API_MSG_DEBUG               LWIP_DBG_OFF
+#define SOCKETS_DEBUG               LWIP_DBG_OFF
+#define ICMP_DEBUG                  LWIP_DBG_OFF
+#define INET_DEBUG                  LWIP_DBG_OFF
+#define IP_DEBUG                    LWIP_DBG_OFF
+#define IP_REASS_DEBUG              LWIP_DBG_OFF
+#define RAW_DEBUG                   LWIP_DBG_OFF
+#define MEM_DEBUG                   LWIP_DBG_OFF
+#define MEMP_DEBUG                  LWIP_DBG_OFF
+#define SYS_DEBUG                   LWIP_DBG_OFF
+#define TCP_DEBUG                   LWIP_DBG_OFF
+#define TCP_INPUT_DEBUG             LWIP_DBG_OFF
+#define TCP_OUTPUT_DEBUG            LWIP_DBG_OFF
+#define TCP_RTO_DEBUG               LWIP_DBG_OFF
+#define TCP_CWND_DEBUG              LWIP_DBG_OFF
+#define TCP_WND_DEBUG               LWIP_DBG_OFF
+#define TCP_FR_DEBUG                LWIP_DBG_OFF
+#define TCP_QLEN_DEBUG              LWIP_DBG_OFF
+#define TCP_RST_DEBUG               LWIP_DBG_OFF
+#define UDP_DEBUG                   LWIP_DBG_OFF
+#define TCPIP_DEBUG                 LWIP_DBG_OFF
+#define PPP_DEBUG                   LWIP_DBG_OFF
+#define SLIP_DEBUG                  LWIP_DBG_OFF
+#define DHCP_DEBUG                  LWIP_DBG_OFF
+
+#endif /* __LWIPOPTS_H__ */

0x0001_hello-world/main.c

@@ -0,0 +1,13 @@
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+
+int main(void)
+{
+    stdio_init_all();
+
+    while (true)
+    {
+        printf("hello, world\r\n");
+    }
+}

0x0001_hello-world/mbedtls_config.h

@@ -0,0 +1,62 @@
+/* Workaround for some mbedtls source files using INT_MAX without including limits.h */
+#include <limits.h>
+
+#define MBEDTLS_NO_PLATFORM_ENTROPY
+#define MBEDTLS_ENTROPY_HARDWARE_ALT
+
+#define MBEDTLS_SSL_OUT_CONTENT_LEN    2048
+
+#define MBEDTLS_ALLOW_PRIVATE_ACCESS
+#define MBEDTLS_HAVE_TIME
+
+#define MBEDTLS_CIPHER_MODE_CBC
+#define MBEDTLS_ECP_DP_SECP192R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP224R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP256R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP384R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP521R1_ENABLED
+#define MBEDTLS_ECP_DP_SECP192K1_ENABLED
+#define MBEDTLS_ECP_DP_SECP224K1_ENABLED
+#define MBEDTLS_ECP_DP_SECP256K1_ENABLED
+#define MBEDTLS_ECP_DP_BP256R1_ENABLED
+#define MBEDTLS_ECP_DP_BP384R1_ENABLED
+#define MBEDTLS_ECP_DP_BP512R1_ENABLED
+#define MBEDTLS_ECP_DP_CURVE25519_ENABLED
+#define MBEDTLS_KEY_EXCHANGE_RSA_ENABLED
+#define MBEDTLS_PKCS1_V15
+#define MBEDTLS_SHA256_SMALLER
+#define MBEDTLS_SSL_SERVER_NAME_INDICATION
+#define MBEDTLS_AES_C
+#define MBEDTLS_ASN1_PARSE_C
+#define MBEDTLS_BIGNUM_C
+#define MBEDTLS_CIPHER_C
+#define MBEDTLS_CTR_DRBG_C
+#define MBEDTLS_ENTROPY_C
+#define MBEDTLS_ERROR_C
+#define MBEDTLS_MD_C
+#define MBEDTLS_MD5_C
+#define MBEDTLS_OID_C
+#define MBEDTLS_PKCS5_C
+#define MBEDTLS_PK_C
+#define MBEDTLS_PK_PARSE_C
+#define MBEDTLS_PLATFORM_C
+#define MBEDTLS_RSA_C
+#define MBEDTLS_SHA1_C
+#define MBEDTLS_SHA224_C
+#define MBEDTLS_SHA256_C
+#define MBEDTLS_SHA512_C
+#define MBEDTLS_SSL_CLI_C
+#define MBEDTLS_SSL_SRV_C
+#define MBEDTLS_SSL_TLS_C
+#define MBEDTLS_X509_CRT_PARSE_C
+#define MBEDTLS_X509_USE_C
+#define MBEDTLS_AES_FEWER_TABLES
+
+/* TLS 1.2 */
+#define MBEDTLS_SSL_PROTO_TLS1_2
+#define MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED
+#define MBEDTLS_GCM_C
+#define MBEDTLS_ECDH_C
+#define MBEDTLS_ECP_C
+#define MBEDTLS_ECDSA_C
+#define MBEDTLS_ASN1_WRITE_C

0x0001_hello-world/pico_sdk_import.cmake

@@ -0,0 +1,73 @@
+# This is a copy of <PICO_SDK_PATH>/external/pico_sdk_import.cmake
+
+# This can be dropped into an external project to help locate this SDK
+# It should be include()ed prior to project()
+
+if (DEFINED ENV{PICO_SDK_PATH} AND (NOT PICO_SDK_PATH))
+    set(PICO_SDK_PATH $ENV{PICO_SDK_PATH})
+    message("Using PICO_SDK_PATH from environment ('${PICO_SDK_PATH}')")
+endif ()
+
+if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT} AND (NOT PICO_SDK_FETCH_FROM_GIT))
+    set(PICO_SDK_FETCH_FROM_GIT $ENV{PICO_SDK_FETCH_FROM_GIT})
+    message("Using PICO_SDK_FETCH_FROM_GIT from environment ('${PICO_SDK_FETCH_FROM_GIT}')")
+endif ()
+
+if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_PATH} AND (NOT PICO_SDK_FETCH_FROM_GIT_PATH))
+    set(PICO_SDK_FETCH_FROM_GIT_PATH $ENV{PICO_SDK_FETCH_FROM_GIT_PATH})
+    message("Using PICO_SDK_FETCH_FROM_GIT_PATH from environment ('${PICO_SDK_FETCH_FROM_GIT_PATH}')")
+endif ()
+
+set(PICO_SDK_PATH "${PICO_SDK_PATH}" CACHE PATH "Path to the Raspberry Pi Pico SDK")
+set(PICO_SDK_FETCH_FROM_GIT "${PICO_SDK_FETCH_FROM_GIT}" CACHE BOOL "Set to ON to fetch copy of SDK from git if not otherwise locatable")
+set(PICO_SDK_FETCH_FROM_GIT_PATH "${PICO_SDK_FETCH_FROM_GIT_PATH}" CACHE FILEPATH "location to download SDK")
+
+if (NOT PICO_SDK_PATH)
+    if (PICO_SDK_FETCH_FROM_GIT)
+        include(FetchContent)
+        set(FETCHCONTENT_BASE_DIR_SAVE ${FETCHCONTENT_BASE_DIR})
+        if (PICO_SDK_FETCH_FROM_GIT_PATH)
+            get_filename_component(FETCHCONTENT_BASE_DIR "${PICO_SDK_FETCH_FROM_GIT_PATH}" REALPATH BASE_DIR "${CMAKE_SOURCE_DIR}")
+        endif ()
+        # GIT_SUBMODULES_RECURSE was added in 3.17
+        if (${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.17.0")
+            FetchContent_Declare(
+                    pico_sdk
+                    GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                    GIT_TAG master
+                    GIT_SUBMODULES_RECURSE FALSE
+            )
+        else ()
+            FetchContent_Declare(
+                    pico_sdk
+                    GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                    GIT_TAG master
+            )
+        endif ()
+
+        if (NOT pico_sdk)
+            message("Downloading Raspberry Pi Pico SDK")
+            FetchContent_Populate(pico_sdk)
+            set(PICO_SDK_PATH ${pico_sdk_SOURCE_DIR})
+        endif ()
+        set(FETCHCONTENT_BASE_DIR ${FETCHCONTENT_BASE_DIR_SAVE})
+    else ()
+        message(FATAL_ERROR
+                "SDK location was not specified. Please set PICO_SDK_PATH or set PICO_SDK_FETCH_FROM_GIT to on to fetch from git."
+                )
+    endif ()
+endif ()
+
+get_filename_component(PICO_SDK_PATH "${PICO_SDK_PATH}" REALPATH BASE_DIR "${CMAKE_BINARY_DIR}")
+if (NOT EXISTS ${PICO_SDK_PATH})
+    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' not found")
+endif ()
+
+set(PICO_SDK_INIT_CMAKE_FILE ${PICO_SDK_PATH}/pico_sdk_init.cmake)
+if (NOT EXISTS ${PICO_SDK_INIT_CMAKE_FILE})
+    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' does not appear to contain the Raspberry Pi Pico SDK")
+endif ()
+
+set(PICO_SDK_PATH ${PICO_SDK_PATH} CACHE PATH "Path to the Raspberry Pi Pico SDK" FORCE)
+
+include(${PICO_SDK_INIT_CMAKE_FILE})

0x0001_hello-world/platformio.ini

@@ -1,16 +0,0 @@
-; PlatformIO Project Configuration File
-;
-;   Build options: build flags, source filter
-;   Upload options: custom upload port, speed and extra flags
-;   Library options: dependencies, extra library storages
-;   Advanced options: extra scripting
-;
-; Please visit documentation for the other options and examples
-; https://docs.platformio.org/page/projectconf.html
-
-[env:genericSTM32F401CC]
-platform = ststm32
-board = genericSTM32F401CC
-framework = stm32cube
-upload_protocol = stlink
-debug_tool = stlink

0x0001_hello-world/src/main.c

@@ -1,22 +0,0 @@
-/**
- * FILE: main.s
- *
- * DESCRIPTION: This file contains the main function for the hello-world program utilizing the STM32F401CC6 microcontroller.
- *
- * AUTHOR: Kevin Thomas
- * DATE: October 6, 2023
- */
-
-#include <stdio.h>
-
-#include "usart.h"
-
-int main(void)
-{
-    usart2_init();
-
-    while (1)
-    {
-        printf("hello, world\r\n");
-    }
-}

0x0001_hello-world/src/usart.c

@@ -1,126 +0,0 @@
-/**
- * FILE: usart.s
- *
- * DESCRIPTION: This file contains the usart functions utilizing the STM32F401CC6 microcontroller.
- *
- * AUTHOR: Kevin Thomas
- * DATE: October 6, 2023
- */
-
-#include "usart.h"
-
-__attribute__((weak)) int _write(int file, char *ptr, int len)
-{
-    (void)file;
-    int data_idx;
-
-    for (data_idx = 0; data_idx < len; data_idx++)
-    {
-        __io_putchar(*ptr++);
-    }
-
-    return len;
-}
-
-int __io_putchar(int char_)
-{
-    // write a single char
-    usart2_write_char(char_);
-
-    return char_;
-}
-
-static void set_baud_rate(USART_TypeDef *USARTx,  uint32_t periph_clk, uint32_t baud_rate)
-{
-    // set baud rate register
-    USARTx->BRR = ((periph_clk + (baud_rate / 2)) / baud_rate);
-}
-
-void usart2_init(void)
-{
-    // enable GPIOA clock
-    RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN;
-
-    // set PA2 to output alternate function mode
-    GPIOA->MODER |= GPIO_MODER_MODE2_1;
-    GPIOA->MODER &= ~GPIO_MODER_MODE2_0;
-
-    // set PA2 alternate function type to UART_TX (AF07)
-    GPIOA->AFR[0] &= ~GPIO_AFRL_AFRL2_3;
-    GPIOA->AFR[0] |= GPIO_AFRL_AFRL2_2;
-    GPIOA->AFR[0] |= GPIO_AFRL_AFRL2_1;
-    GPIOA->AFR[0] |= GPIO_AFRL_AFRL2_0;
-
-    // set PA3 to output alternate function mode
-    GPIOA->MODER |= GPIO_MODER_MODE3_1;
-    GPIOA->MODER &= ~GPIO_MODER_MODE3_0;
-
-    // set PA3 alternate function type to UART_RX (AF07)
-    GPIOA->AFR[0] &= ~GPIO_AFRL_AFRL3_3;
-    GPIOA->AFR[0] |= GPIO_AFRL_AFRL3_2;
-    GPIOA->AFR[0] |= GPIO_AFRL_AFRL3_1;
-    GPIOA->AFR[0] |= GPIO_AFRL_AFRL3_0;
-
-    // enable USART2 clock
-    RCC->APB1ENR |= RCC_APB1ENR_USART2EN;
-
-    // configure baud rate to 9600
-    set_baud_rate(USART2, DEFAULT_CLK_SPEED, 9600);
-
-    // configure TX transmitter enable
-    USART2->CR1 |= USART_CR1_TE;
-
-    // configure RX receiver enable
-    USART2->CR1 |= USART_CR1_RE;
-
-    // enable UART2
-    USART2->CR1 |= USART_CR1_UE;
-}
-
-void usart2_write_char(uint8_t char_)
-{
-    // verify transmit data register is empty, will return true if the bit is set
-    while(!(USART2->SR & USART_SR_TXE)) {};
-
-    // write a single char to the data register
-    USART2->DR = (char_ & 0xFF);
-}
-
-char usart2_read_char(void)
-{
-    // verify receive data register is empty, will return true if the bit is set
-    while(!(USART2->SR & USART_SR_RXNE)) {};
-
-    // return a single char from the data register
-    return USART2->DR;
-}
-
-void input(char *buffer, size_t buffer_size)
-{
-    char input;
-    size_t i = 0;
-
-    while (1)
-    {
-        input = usart2_read_char();
-
-        // check for newline or carriage return
-        if (input == '\n' || input == '\r')  
-        {
-            // null-terminate the string
-            buffer[i] = '\0';  
-            break;
-        }
-
-        // append new char from usart into buffer
-        buffer[i++] = input;
-
-        // ensure we don't overflow the buffer
-        if (i >= buffer_size - 1)
-        {
-            // null-terminate the string
-            buffer[i] = '\0';  
-            break;
-        }
-    }
-}

0x0001_hello-world/test/README

@@ -1,11 +0,0 @@
-
-This directory is intended for PlatformIO Test Runner and project tests.
-
-Unit Testing is a software testing method by which individual units of
-source code, sets of one or more MCU program modules together with associated
-control data, usage procedures, and operating procedures, are tested to
-determine whether they are fit for use. Unit testing finds problems early
-in the development cycle.
-
-More information about PlatformIO Unit Testing:
-- https://docs.platformio.org/en/latest/advanced/unit-testing/index.html

openocd.ps1

@@ -0,0 +1,14 @@
+# store the current location
+$originalLocation = Get-Location
+
+try {
+    # change the location to the OpenOCD scripts directory
+    Set-Location -Path "C:\Program Files\Raspberry Pi\Pico SDK v1.5.0\openocd\scripts"
+
+    # run OpenOCD
+    ../openocd -f interface/cmsis-dap.cfg -f target/rp2040.cfg -c "adapter speed 5000"
+}
+finally {
+    # return to the original location
+    Set-Location -Path $originalLocation
+}