mirror of
https://github.com/mytechnotalent/Embedded-Hacking.git
synced 2026-08-15 15:40:19 +02:00
Drivers
This commit is contained in:
Kevin Thomas
@@ -0,0 +1,65 @@
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/**
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* @file 0x04_pwm.c
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* @brief PWM demonstration: LED breathing effect via duty-cycle sweep
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* @author Kevin Thomas
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* @date 2025
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*
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* MIT License
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*
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* Copyright (c) 2025 Kevin Thomas
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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* -----------------------------------------------------------------------------
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*
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* Demonstrates PWM output using the pwm driver (pwm.h / pwm.c). A 1 kHz
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* signal on GPIO 0 sweeps its duty cycle from 0% to 100% and back to
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* produce a smooth LED breathing effect. The current duty is reported
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* over UART.
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*
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* Wiring:
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* GPIO0 -> LED anode (with 330 ohm series resistor to GND)
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*/
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#include <stdio.h>
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#include "pico/stdlib.h"
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#include "pwm.h"
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#define PWM_PIN 0
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#define PWM_FREQ_HZ 1000
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int main(void) {
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stdio_init_all();
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pwm_driver_init(PWM_PIN, PWM_FREQ_HZ);
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printf("PWM driver initialized: GPIO%d @ %d Hz\r\n", PWM_PIN, PWM_FREQ_HZ);
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while (true) {
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for (int duty = 0; duty <= 100; duty += 5) {
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pwm_driver_set_duty_percent((uint8_t)duty);
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printf("Duty: %3d%%\r\n", duty);
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sleep_ms(50);
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}
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for (int duty = 100; duty >= 0; duty -= 5) {
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pwm_driver_set_duty_percent((uint8_t)duty);
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printf("Duty: %3d%%\r\n", duty);
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sleep_ms(50);
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}
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}
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}
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@@ -0,0 +1,58 @@
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# Generated Cmake Pico project file
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cmake_minimum_required(VERSION 3.13)
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set(CMAKE_C_STANDARD 11)
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set(CMAKE_CXX_STANDARD 17)
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set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
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# Initialise pico_sdk from installed location
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# (note this can come from environment, CMake cache etc)
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# == DO NOT EDIT THE FOLLOWING LINES for the Raspberry Pi Pico VS Code Extension to work ==
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if(WIN32)
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set(USERHOME $ENV{USERPROFILE})
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else()
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set(USERHOME $ENV{HOME})
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endif()
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set(sdkVersion 2.2.0)
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set(toolchainVersion 14_2_Rel1)
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set(picotoolVersion 2.2.0)
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set(picoVscode ${USERHOME}/.pico-sdk/cmake/pico-vscode.cmake)
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if (EXISTS ${picoVscode})
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include(${picoVscode})
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endif()
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# ====================================================================================
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set(PICO_BOARD pico2 CACHE STRING "Board type")
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# Pull in Raspberry Pi Pico SDK (must be before project)
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include(pico_sdk_import.cmake)
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project(0x04_pwm C CXX ASM)
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# Initialise the Raspberry Pi Pico SDK
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pico_sdk_init()
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# Add executable. Default name is the project name, version 0.1
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add_executable(0x04_pwm 0x04_pwm.c pwm.c)
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pico_set_program_name(0x04_pwm "0x04_pwm")
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pico_set_program_version(0x04_pwm "0.1")
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# Modify the below lines to enable/disable output over UART/USB
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pico_enable_stdio_uart(0x04_pwm 1)
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pico_enable_stdio_usb(0x04_pwm 0)
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# Add the standard library to the build
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target_link_libraries(0x04_pwm
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pico_stdlib
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hardware_pwm
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hardware_clocks)
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# Add the standard include files to the build
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target_include_directories(0x04_pwm PRIVATE
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${CMAKE_CURRENT_LIST_DIR}
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)
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pico_add_extra_outputs(0x04_pwm)
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@@ -0,0 +1,121 @@
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# This is a copy of <PICO_SDK_PATH>/external/pico_sdk_import.cmake
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# This can be dropped into an external project to help locate this SDK
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# It should be include()ed prior to project()
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# Copyright 2020 (c) 2020 Raspberry Pi (Trading) Ltd.
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#
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# Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
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# following conditions are met:
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#
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# 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
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# disclaimer.
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#
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# 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
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# disclaimer in the documentation and/or other materials provided with the distribution.
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#
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# 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products
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# derived from this software without specific prior written permission.
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#
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
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# INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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if (DEFINED ENV{PICO_SDK_PATH} AND (NOT PICO_SDK_PATH))
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set(PICO_SDK_PATH $ENV{PICO_SDK_PATH})
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message("Using PICO_SDK_PATH from environment ('${PICO_SDK_PATH}')")
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endif ()
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if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT} AND (NOT PICO_SDK_FETCH_FROM_GIT))
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set(PICO_SDK_FETCH_FROM_GIT $ENV{PICO_SDK_FETCH_FROM_GIT})
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message("Using PICO_SDK_FETCH_FROM_GIT from environment ('${PICO_SDK_FETCH_FROM_GIT}')")
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endif ()
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if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_PATH} AND (NOT PICO_SDK_FETCH_FROM_GIT_PATH))
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set(PICO_SDK_FETCH_FROM_GIT_PATH $ENV{PICO_SDK_FETCH_FROM_GIT_PATH})
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message("Using PICO_SDK_FETCH_FROM_GIT_PATH from environment ('${PICO_SDK_FETCH_FROM_GIT_PATH}')")
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endif ()
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if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_TAG} AND (NOT PICO_SDK_FETCH_FROM_GIT_TAG))
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set(PICO_SDK_FETCH_FROM_GIT_TAG $ENV{PICO_SDK_FETCH_FROM_GIT_TAG})
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message("Using PICO_SDK_FETCH_FROM_GIT_TAG from environment ('${PICO_SDK_FETCH_FROM_GIT_TAG}')")
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endif ()
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if (PICO_SDK_FETCH_FROM_GIT AND NOT PICO_SDK_FETCH_FROM_GIT_TAG)
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set(PICO_SDK_FETCH_FROM_GIT_TAG "master")
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message("Using master as default value for PICO_SDK_FETCH_FROM_GIT_TAG")
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endif()
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set(PICO_SDK_PATH "${PICO_SDK_PATH}" CACHE PATH "Path to the Raspberry Pi Pico SDK")
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set(PICO_SDK_FETCH_FROM_GIT "${PICO_SDK_FETCH_FROM_GIT}" CACHE BOOL "Set to ON to fetch copy of SDK from git if not otherwise locatable")
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set(PICO_SDK_FETCH_FROM_GIT_PATH "${PICO_SDK_FETCH_FROM_GIT_PATH}" CACHE FILEPATH "location to download SDK")
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set(PICO_SDK_FETCH_FROM_GIT_TAG "${PICO_SDK_FETCH_FROM_GIT_TAG}" CACHE FILEPATH "release tag for SDK")
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if (NOT PICO_SDK_PATH)
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if (PICO_SDK_FETCH_FROM_GIT)
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include(FetchContent)
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set(FETCHCONTENT_BASE_DIR_SAVE ${FETCHCONTENT_BASE_DIR})
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if (PICO_SDK_FETCH_FROM_GIT_PATH)
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get_filename_component(FETCHCONTENT_BASE_DIR "${PICO_SDK_FETCH_FROM_GIT_PATH}" REALPATH BASE_DIR "${CMAKE_SOURCE_DIR}")
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endif ()
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FetchContent_Declare(
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pico_sdk
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GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
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GIT_TAG ${PICO_SDK_FETCH_FROM_GIT_TAG}
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)
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if (NOT pico_sdk)
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message("Downloading Raspberry Pi Pico SDK")
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# GIT_SUBMODULES_RECURSE was added in 3.17
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if (${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.17.0")
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FetchContent_Populate(
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pico_sdk
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QUIET
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GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
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GIT_TAG ${PICO_SDK_FETCH_FROM_GIT_TAG}
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GIT_SUBMODULES_RECURSE FALSE
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SOURCE_DIR ${FETCHCONTENT_BASE_DIR}/pico_sdk-src
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BINARY_DIR ${FETCHCONTENT_BASE_DIR}/pico_sdk-build
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SUBBUILD_DIR ${FETCHCONTENT_BASE_DIR}/pico_sdk-subbuild
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)
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else ()
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FetchContent_Populate(
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pico_sdk
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QUIET
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GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
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GIT_TAG ${PICO_SDK_FETCH_FROM_GIT_TAG}
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SOURCE_DIR ${FETCHCONTENT_BASE_DIR}/pico_sdk-src
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BINARY_DIR ${FETCHCONTENT_BASE_DIR}/pico_sdk-build
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SUBBUILD_DIR ${FETCHCONTENT_BASE_DIR}/pico_sdk-subbuild
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)
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endif ()
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set(PICO_SDK_PATH ${pico_sdk_SOURCE_DIR})
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endif ()
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set(FETCHCONTENT_BASE_DIR ${FETCHCONTENT_BASE_DIR_SAVE})
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else ()
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message(FATAL_ERROR
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"SDK location was not specified. Please set PICO_SDK_PATH or set PICO_SDK_FETCH_FROM_GIT to on to fetch from git."
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)
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endif ()
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endif ()
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get_filename_component(PICO_SDK_PATH "${PICO_SDK_PATH}" REALPATH BASE_DIR "${CMAKE_BINARY_DIR}")
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if (NOT EXISTS ${PICO_SDK_PATH})
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message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' not found")
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endif ()
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set(PICO_SDK_INIT_CMAKE_FILE ${PICO_SDK_PATH}/pico_sdk_init.cmake)
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if (NOT EXISTS ${PICO_SDK_INIT_CMAKE_FILE})
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message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' does not appear to contain the Raspberry Pi Pico SDK")
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endif ()
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set(PICO_SDK_PATH ${PICO_SDK_PATH} CACHE PATH "Path to the Raspberry Pi Pico SDK" FORCE)
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include(${PICO_SDK_INIT_CMAKE_FILE})
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@@ -0,0 +1,74 @@
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/**
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* @file pwm.c
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* @brief Implementation of the generic PWM output driver
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* @author Kevin Thomas
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* @date 2025
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*
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* MIT License
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*
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* Copyright (c) 2025 Kevin Thomas
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
|
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
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* copies of the Software, and to permit persons to whom the Software is
|
||||
* furnished to do so, subject to the following conditions:
|
||||
*
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* The above copyright notice and this permission notice shall be included in all
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||||
* copies or substantial portions of the Software.
|
||||
*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||||
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
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* SOFTWARE.
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*/
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#include "pwm.h"
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#include "pico/stdlib.h"
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#include "hardware/pwm.h"
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#include "hardware/clocks.h"
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static uint pwm_slice;
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static uint pwm_chan;
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static uint32_t pwm_wrap;
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/**
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* @brief Compute the PWM clock divider that yields the target frequency
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*
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* Derives a floating-point divider from the current system clock frequency,
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* the desired output frequency, and the chosen wrap value so that the PWM
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* counter overflows exactly freq_hz times per second.
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*
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* @param freq_hz Desired PWM output frequency in Hz
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* @param wrap_val Chosen PWM counter wrap value (period - 1)
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* @return float Clock divider to program into the PWM slice
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*/
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static float calc_clk_div(uint32_t freq_hz, uint32_t wrap_val) {
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uint32_t sys_hz = clock_get_hz(clk_sys);
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return (float)sys_hz / ((float)freq_hz * (float)(wrap_val + 1));
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}
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void pwm_driver_init(uint32_t pin, uint32_t freq_hz) {
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gpio_set_function(pin, GPIO_FUNC_PWM);
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pwm_slice = pwm_gpio_to_slice_num(pin);
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pwm_chan = pwm_gpio_to_channel(pin);
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pwm_wrap = 10000 - 1; // resolution: 0.01% steps
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pwm_config cfg = pwm_get_default_config();
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pwm_config_set_clkdiv(&cfg, calc_clk_div(freq_hz, pwm_wrap));
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pwm_config_set_wrap(&cfg, pwm_wrap);
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pwm_init(pwm_slice, &cfg, true);
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pwm_set_chan_level(pwm_slice, pwm_chan, 0);
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}
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void pwm_driver_set_duty_percent(uint8_t percent) {
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if (percent > 100) {
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percent = 100;
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}
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uint32_t level = ((uint32_t)percent * (pwm_wrap + 1)) / 100;
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pwm_set_chan_level(pwm_slice, pwm_chan, level);
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}
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@@ -0,0 +1,59 @@
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/**
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* @file pwm.h
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* @brief Header for generic PWM output driver
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* @author Kevin Thomas
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* @date 2025
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||||
*
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||||
* MIT License
|
||||
*
|
||||
* Copyright (c) 2025 Kevin Thomas
|
||||
*
|
||||
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
||||
* of this software and associated documentation files (the "Software"), to deal
|
||||
* in the Software without restriction, including without limitation the rights
|
||||
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||||
* copies of the Software, and to permit persons to whom the Software is
|
||||
* furnished to do so, subject to the following conditions:
|
||||
*
|
||||
* The above copyright notice and this permission notice shall be included in all
|
||||
* copies or substantial portions of the Software.
|
||||
*
|
||||
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||||
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||||
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
||||
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
||||
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
||||
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
||||
* SOFTWARE.
|
||||
*/
|
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|
||||
#ifndef PWM_H
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#define PWM_H
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#include <stdint.h>
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/**
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* @brief Initialize PWM output on the specified GPIO pin at a target frequency
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*
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* Assigns the GPIO pin to the PWM function, calculates the clock divider and
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* wrap value from the system clock to achieve the requested frequency, then
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* starts the PWM slice with a 0% duty cycle. Must be called once before using
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* pwm_driver_set_duty_percent().
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*
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* @param pin GPIO pin number to drive with PWM output
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* @param freq_hz Desired PWM frequency in Hz (e.g. 1000 for 1 kHz)
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*/
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void pwm_driver_init(uint32_t pin, uint32_t freq_hz);
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/**
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* @brief Set the PWM duty cycle as an integer percentage
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*
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* Maps the percentage value to the internal PWM counter range and writes
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* the result to the channel level register. Values above 100 are clamped
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* to 100.
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*
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* @param percent Duty cycle from 0 (always low) to 100 (always high)
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*/
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void pwm_driver_set_duty_percent(uint8_t percent);
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||||
#endif // PWM_H
|
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