LAB 2A: Siyun Wang Worked with: Wenxi Wei and Zhijing Yao

README.md

@@ -1,9 +1,55 @@
 University of Pennsylvania, ESE 5190: Intro to Embedded Systems, Lab 2A
 
-    (TODO) YOUR NAME HERE
-        (TODO) LinkedIn, personal website, twitter, etc.
-    Tested on: (TODO) MacBook Pro (14-inch, 2021), macOS Monterey 12.5.1
+    Siyun Wang
+    https://github.com/Phoebe-www/ese5190-2022-lab2-into-the-void-star/blob/main/README.md 
+    Tested on: DELL Inspiron 5505, Windows 10
 
-(TODO: Your README)
 
 Include lab questions, screenshots, analysis, etc. (Remember, this is public, so don't put anything here you don't want to share with the world.)
+## 3.2
+
+## 1.Why is bit-banging impractical on your laptop, despite it having a much faster processor than the RP2040?
+One reason is that the timing uncertainty of actually entering an interrupt handler. When the processor is doing the "bit-banging", it cannot be used for other tasks. And also the processor speed is much higher than protocol speed, therefore there will waste mauch time to waiting.
+
+## 2.What are some cases where directly using the GPIO might be a better choice than using the PIO hardware?
+GPIO might be a better choice than using the PIO hardware on simpler embedded systems.
+
+## 3. How do you get data into a PIO state machine?
+The processor can push data directly into the state machine’s TXFIFO using the pio_sm_put_blocking() function. 
+
+## 4.How do you get data out of a PIO state machine? 
+First write a pio code where when we execute an "out" statement, the data is written to the specific pin mentioned in that statement.
+
+## 5. How do you program a PIO state machine?
+We need to use these functions, like pio_gpio_init(pio, pin); pio_set_consecutive_pindirs(pio, sm, pin, 1, true);  pio_sm_config c = ws2812_program_default_config(offset); sm_config_sideset_pins(&c, pin); sm_config_out_shift(&c, false, true, rgbw ? 32 : 24); int cycles_per_bit = ws2812_T1 + ws2812_T2 + ws2812_T3; float div = clock_get_hz(clk_sys) / (freq * cycles_per_bit); sm_config_clkdiv(&c, div); pio_sm_init(pio, sm, offset, &c); pio_sm_enable(pio, sm, true);
+
+## 6. In the example, which low-level C SDK function is directly responsible for telling the PIO to set the LED to a new color? How is this function accessed from the main “application” code?
+ static inline void put_pixel(uint32_t pixel_grb) {
+   pio_sm_put_blocking(pio0, 0, pixel_grb << 8u);
+   }
+
+## 7.  What role does the pioasm “assembler” play in the example, and how does this interact with CMake?
+we can use it to build your PIO programs, for you to #include from your C or C++ program. pioasm can also be used directly, and has a few features not used by the C++ SDK, such as generating programs suitable for use with the MicroPython PIO library. And CMake function pico_generate_pio_header(TARGET PIO_FILE) takes care of invoking pioasm and adding the generated header to the include path of the target TARGET.
+
+
+## 3.3 
+
+[3.3.pdf](https://github.com/Phoebe-www/ese5190-2022-lab2-into-the-void-star/files/9806261/3.3.pdf)
+
+## 3.4
+
+We chose the color: 0x0000ff(Blue)
+[RegistersList.pdf](https://github.com/Phoebe-www/ese5190-2022-lab2-into-the-void-star/files/9806768/RegistersList.pdf)
+
+## 3.5
+
+[3.5(2).pdf](https://github.com/Phoebe-www/ese5190-2022-lab2-into-the-void-star/files/9807845/3.5.2.pdf)
+
+
+
+## 3.6，3.7
+
+[3.6_3.7.xlsx](https://github.com/Phoebe-www/ese5190-2022-lab2-into-the-void-star/files/9808928/3.6_3.7.xlsx)
+
+
+

lab2A/CMakeLists.txt

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+cmake_minimum_required(VERSION 3.12)
+
+# Pull in SDK (must be before project)
+include(pico_sdk_import.cmake)
+
+project(pico_examples C CXX ASM)
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_CXX_STANDARD 17)
+
+if (PICO_SDK_VERSION_STRING VERSION_LESS "1.3.0")
+    message(FATAL_ERROR "Raspberry Pi Pico SDK version 1.3.0 (or later) required. Your version is ${PICO_SDK_VERSION_STRING}")
+endif()
+
+set(PICO_EXAMPLES_PATH ${PROJECT_SOURCE_DIR})
+
+# Initialize the SDK
+pico_sdk_init()
+
+include(example_auto_set_url.cmake)
+
+
+add_compile_options(-Wall
+        -Wno-format          # int != int32_t as far as the compiler is concerned because gcc has int32_t as long int
+        -Wno-unused-function # we have some for the docs that aren't called
+        -Wno-maybe-uninitialized
+        )
+
+# Hardware-specific examples in subdirectories:
+add_subdirectory(pio)
+

lab2A/CONTRIBUTING.md

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+# Contributing to Raspberry Pi Pico C/C++ Examples
+
+## How to Report a Bug
+
+We use GitHub to host code, track [issues](https://github.com/raspberrypi/pico-examples/issues) and feature requests, and to accept [pull requests](https://github.com/raspberrypi/pico-examples/pulls). If you find think you have found a bug, please report it by [opening a new issue](https://github.com/raspberrypi/pico-examples/issues/new). Please include as much detail as possible, and ideally some code to reproduce the problem.
+
+## How to Contribute Code
+
+In order to contribute new or updated code, you must first create a GitHub account and fork the original repository to your own account. You can make changes, save them in your repository, then [make a pull request](https://docs.github.com/en/github/collaborating-with-pull-requests/proposing-changes-to-your-work-with-pull-requests/creating-a-pull-request-from-a-fork) against this repository. The pull request will appear [in the repository](https://github.com/raspberrypi/pico-examples/pulls) where it can be assessed by the maintainers, and if appropriate, merged with the official repository.
+
+**NOTE:** Development takes place on the `develop` branch in this repository. Please open your https://github.com/raspberrypi/pico-examples/pulls[pull request] (PR) against the [`develop`](https://github.com/raspberrypi/pico-examples/tree/develop) branch, pull requests against the `master` branch will automatically CI fail checks and will not be accepted. You will be asked to rebase your PR against `develop` and if you do not do so, your PR will be closed.
+
+### Code Style
+
+If you are contributing new or updated code please match the existing code style, particularly:
+
+* Use 4 spaces for indentation rather than tabs.
+* Braces are required for everything except single line `if` statements.
+* Opening braces should not be placed on a new line.
+
+### Licensing
+
+Code in this repository is lisensed under the [BSD-3 License](LICENSE.TXT). By contributing content to this repository you are agreeing to place your contributions under this licence.

lab2A/LICENSE.TXT

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+Copyright 2020 (c) 2020 Raspberry Pi (Trading) Ltd.
+
+Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
+following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
+   disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
+   disclaimer in the documentation and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products
+   derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

lab2A/example_auto_set_url.cmake

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+set(PICO_EXAMPLE_URL_BASE "https://github.com/raspberrypi/pico-examples/tree/HEAD")
+macro(example_auto_set_url TARGET)
+    file(RELATIVE_PATH URL_REL_PATH "${PICO_EXAMPLES_PATH}" "${CMAKE_CURRENT_LIST_DIR}")
+    pico_set_program_url(${TARGET} "${PICO_EXAMPLE_URL_BASE}/${URL_REL_PATH}")
+endmacro()

lab2A/pico_sdk_import.cmake

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+# 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})

lab2A/pio/CMakeLists.txt

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+if (NOT PICO_NO_HARDWARE)
+    add_subdirectory(ws2812)
+endif ()

lab2A/pio/ws2812/CMakeLists.txt

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+add_executable(pio_ws2812)
+
+# generate the header file into the source tree as it is included in the RP2040 datasheet
+pico_generate_pio_header(pio_ws2812 ${CMAKE_CURRENT_LIST_DIR}/ws2812.pio OUTPUT_DIR ${CMAKE_CURRENT_LIST_DIR}/generated)
+
+target_sources(pio_ws2812 PRIVATE ws2812.c hello_usb.c ws2812.h) 
+
+pico_enable_stdio_usb(pio_ws2812 1)
+pico_enable_stdio_uart(pio_ws2812 0)
+
+target_link_libraries(pio_ws2812 PRIVATE pico_stdlib hardware_pio)
+pico_add_extra_outputs(pio_ws2812)
+
+# add url via pico_set_program_url
+example_auto_set_url(pio_ws2812)
+
+add_executable(pio_ws2812_parallel)
+
+pico_generate_pio_header(pio_ws2812_parallel ${CMAKE_CURRENT_LIST_DIR}/ws2812.pio OUTPUT_DIR ${CMAKE_CURRENT_LIST_DIR}/generated)
+
+target_sources(pio_ws2812_parallel PRIVATE ws2812_parallel.c)
+
+target_compile_definitions(pio_ws2812_parallel PRIVATE
+        PIN_DBG1=3)
+
+target_link_libraries(pio_ws2812_parallel PRIVATE pico_stdlib hardware_pio hardware_dma)
+pico_add_extra_outputs(pio_ws2812_parallel)
+
+# add url via pico_set_program_url
+example_auto_set_url(pio_ws2812_parallel)
+
+# Additionally generate python and hex pioasm outputs for inclusion in the RP2040 datasheet
+add_custom_target(pio_ws2812_datasheet DEPENDS ${CMAKE_CURRENT_LIST_DIR}/generated/ws2812.py)
+add_custom_command(OUTPUT ${CMAKE_CURRENT_LIST_DIR}/generated/ws2812.py
+        DEPENDS ${CMAKE_CURRENT_LIST_DIR}/ws2812.pio
+        COMMAND Pioasm -o python ${CMAKE_CURRENT_LIST_DIR}/ws2812.pio ${CMAKE_CURRENT_LIST_DIR}/generated/ws2812.py
+        )
+add_dependencies(pio_ws2812 pio_ws2812_datasheet)

lab2A/pio/ws2812/generated/ws2812.pio.h

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+// -------------------------------------------------- //
+// This file is autogenerated by pioasm; do not edit! //
+// -------------------------------------------------- //
+
+#pragma once
+
+#if !PICO_NO_HARDWARE
+#include "hardware/pio.h"
+#endif
+
+// ------ //
+// ws2812 //
+// ------ //
+
+#define ws2812_wrap_target 0
+#define ws2812_wrap 3
+
+#define ws2812_T1 2
+#define ws2812_T2 5
+#define ws2812_T3 3
+
+static const uint16_t ws2812_program_instructions[] = {
+            //     .wrap_target
+    0x6221, //  0: out    x, 1            side 0 [2] 
+    0x1123, //  1: jmp    !x, 3           side 1 [1] 
+    0x1400, //  2: jmp    0               side 1 [4] 
+    0xa442, //  3: nop                    side 0 [4] 
+            //     .wrap
+};
+
+#if !PICO_NO_HARDWARE
+static const struct pio_program ws2812_program = {
+    .instructions = ws2812_program_instructions,
+    .length = 4,
+    .origin = -1,
+};
+
+static inline pio_sm_config ws2812_program_get_default_config(uint offset) {
+    pio_sm_config c = pio_get_default_sm_config();
+    sm_config_set_wrap(&c, offset + ws2812_wrap_target, offset + ws2812_wrap);
+    sm_config_set_sideset(&c, 1, false, false);
+    return c;
+}
+
+#include "hardware/clocks.h"
+static inline void ws2812_program_init(PIO pio, uint sm, uint offset, uint pin, float freq, bool rgbw) {
+    pio_gpio_init(pio, pin);
+    pio_sm_set_consecutive_pindirs(pio, sm, pin, 1, true);
+    pio_sm_config c = ws2812_program_get_default_config(offset);
+    sm_config_set_sideset_pins(&c, pin);
+    sm_config_set_out_shift(&c, false, true, rgbw ? 32 : 24);
+    sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX);
+    int cycles_per_bit = ws2812_T1 + ws2812_T2 + ws2812_T3;
+    float div = clock_get_hz(clk_sys) / (freq * cycles_per_bit);
+    sm_config_set_clkdiv(&c, div);
+    pio_sm_init(pio, sm, offset, &c);
+    pio_sm_set_enabled(pio, sm, true);
+}
+
+#endif
+
+// --------------- //
+// ws2812_parallel //
+// --------------- //
+
+#define ws2812_parallel_wrap_target 0
+#define ws2812_parallel_wrap 3
+
+#define ws2812_parallel_T1 2
+#define ws2812_parallel_T2 5
+#define ws2812_parallel_T3 3
+
+static const uint16_t ws2812_parallel_program_instructions[] = {
+            //     .wrap_target
+    0x6020, //  0: out    x, 32                      
+    0xa10b, //  1: mov    pins, !null            [1] 
+    0xa401, //  2: mov    pins, x                [4] 
+    0xa103, //  3: mov    pins, null             [1] 
+            //     .wrap
+};
+
+#if !PICO_NO_HARDWARE
+static const struct pio_program ws2812_parallel_program = {
+    .instructions = ws2812_parallel_program_instructions,
+    .length = 4,
+    .origin = -1,
+};
+
+static inline pio_sm_config ws2812_parallel_program_get_default_config(uint offset) {
+    pio_sm_config c = pio_get_default_sm_config();
+    sm_config_set_wrap(&c, offset + ws2812_parallel_wrap_target, offset + ws2812_parallel_wrap);
+    return c;
+}
+
+#include "hardware/clocks.h"
+static inline void ws2812_parallel_program_init(PIO pio, uint sm, uint offset, uint pin_base, uint pin_count, float freq) {
+    for(uint i=pin_base; i<pin_base+pin_count; i++) {
+        pio_gpio_init(pio, i);
+    }
+    pio_sm_set_consecutive_pindirs(pio, sm, pin_base, pin_count, true);
+    pio_sm_config c = ws2812_parallel_program_get_default_config(offset);
+    sm_config_set_out_shift(&c, true, true, 32);
+    sm_config_set_out_pins(&c, pin_base, pin_count);
+    sm_config_set_set_pins(&c, pin_base, pin_count);
+    sm_config_set_fifo_join(&c, PIO_FIFO_JOIN_TX);
+    int cycles_per_bit = ws2812_parallel_T1 + ws2812_parallel_T2 + ws2812_parallel_T3;
+    float div = clock_get_hz(clk_sys) / (freq * cycles_per_bit);
+    sm_config_set_clkdiv(&c, div);
+    pio_sm_init(pio, sm, offset, &c);
+    pio_sm_set_enabled(pio, sm, true);
+}
+
+#endif
+