CalvinBackup/Embedded-Hacking
1
0
Fork 0
mirror of https://github.com/mytechnotalent/Embedded-Hacking.git synced 2026-05-24 00:14:04 +02:00
Code Issues Packages Projects Releases Wiki Activity

style: enforce coding standard — headers, @brief on #define, Doxygen on statics, remove _ prefix, max 8 lines per function

Browse Source
This commit is contained in:
Kevin Thomas
2026-04-16 22:44:43 -04:00
parent 0833c32c94
commit 433263eac0
309 changed files with 10464 additions and 6668 deletions
Download Patch File Download Diff File Expand all files Collapse all files
0x0020_dynamic-conditionals/0x0020_dynamic-conditionals.c
+97 -30
View File
@@ -1,44 +1,111 @@
/**
* @file 0x0020_dynamic-conditionals.c
* @brief Dynamic conditionals: UART input drives if/else and switch with servo
* @author Kevin Thomas
* @date 2025
*
* 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.
*
* -----------------------------------------------------------------------------
*
* Demonstrates dynamic (runtime) conditionals using UART input via getchar().
* Reads a character, evaluates it with if/else and switch/case, and controls
* a servo on GPIO6 based on the input ('1' or '2').
*
* Wiring:
* GPIO6 -> Servo signal wire (orange/white)
* 5V -> Servo VCC (red)
* GND -> Servo GND (brown/black)
*/
#include <stdio.h>
#include "pico/stdlib.h"
#include "servo.h"
/** @brief GPIO pin number for the servo */
#define SERVO_GPIO 6
/**
* @brief Evaluate choice with if/else conditional and print result
*
* @details Compares against hex ASCII values 0x31 ('1') and 0x32 ('2').
*
* @param choice character value received from UART
* @retval None
*/
static void eval_if_else(uint8_t choice) {
if (choice == 0x31) {
printf("1\r\n");
} else if (choice == 0x32) {
printf("2\r\n");
} else {
printf("??\r\n");
}
}
/**
* @brief Sweep servo from start angle to end angle with a pause
*
* @details Sets the servo to start, waits 500 ms, sets to end,
* waits 500 ms.
*
* @param label text to print before sweeping
* @param start starting angle in degrees
* @param end ending angle in degrees
* @retval None
*/
static void sweep_servo(const char *label, float start, float end) {
printf("%s\r\n", label);
servo_set_angle(start);
sleep_ms(500);
servo_set_angle(end);
sleep_ms(500);
}
/**
* @brief Process choice with switch/case and drive servo accordingly
*
* @details On '1', sweeps servo 0->180; on '2', sweeps 180->0;
* otherwise prints unknown.
*
* @param choice character value received from UART
* @retval None
*/
static void process_servo_command(uint8_t choice) {
switch (choice) {
case '1': sweep_servo("one", 0.0f, 180.0f); break;
case '2': sweep_servo("two", 180.0f, 0.0f); break;
default: printf("??\r\n");
}
}
int main(void) {
stdio_init_all();
uint8_t choice = 0;
servo_init(SERVO_GPIO);
while (true) {
choice = getchar();
if (choice == 0x31) {
printf("1\r\n");
} else if (choice == 0x32) {
printf("2\r\n");
} else {
printf("??\r\n");
}
switch (choice) {
case '1':
printf("one\r\n");
servo_set_angle(0.0f);
sleep_ms(500);
servo_set_angle(180.0f);
sleep_ms(500);
break;
case '2':
printf("two\r\n");
servo_set_angle(180.0f);
sleep_ms(500);
servo_set_angle(0.0f);
sleep_ms(500);
break;
default:
printf("??\r\n");
}
eval_if_else(choice);
process_servo_command(choice);
}
}
0x0020_dynamic-conditionals/servo.c
+39 -21
View File
@@ -32,46 +32,66 @@
#include "hardware/pwm.h"
#include "hardware/clocks.h"
// Default servo pulse range (SG90 typical)
/** @brief Default minimum pulse width in microseconds */
static const uint16_t SERVO_DEFAULT_MIN_US = 1000;
/** @brief Default maximum pulse width in microseconds */
static const uint16_t SERVO_DEFAULT_MAX_US = 2000;
// internal state
/** @brief GPIO pin assigned to the servo */
static uint8_t servo_pin = 0;
/** @brief PWM hardware slice for the servo pin */
static uint servo_slice = 0;
/** @brief PWM channel within the servo slice */
static uint servo_chan = 0;
static uint32_t servo_wrap = 20000 - 1; // wrap to map microseconds for 50Hz
/** @brief PWM counter wrap value for 50 Hz servo */
static uint32_t servo_wrap = 20000 - 1;
/** @brief Servo PWM frequency in Hz */
static float servo_hz = 50.0f;
/** @brief Flag indicating servo has been initialized */
static bool servo_initialized = false;
// Convert microsecond pulse to PWM level based on wrap and frequency
/**
* @brief Convert a pulse width in microseconds to a PWM counter level
*
* Uses the configured PWM wrap and servo frequency to map pulse time
* into the channel compare value expected by the PWM hardware.
*
* @param pulse_us Pulse width in microseconds
* @return uint32_t PWM level suitable for pwm_set_chan_level()
*/
static uint32_t pulse_us_to_level(uint32_t pulse_us) {
const float period_us = 1000000.0f / servo_hz; // 20000us
const float period_us = 1000000.0f / servo_hz;
float counts_per_us = (servo_wrap + 1) / period_us;
return (uint32_t)(pulse_us * counts_per_us + 0.5f);
}
void servo_init(uint8_t pin) {
servo_pin = pin;
// Configure GPIO for PWM
gpio_set_function(servo_pin, GPIO_FUNC_PWM);
servo_slice = pwm_gpio_to_slice_num(servo_pin);
servo_chan = pwm_gpio_to_channel(servo_pin);
/**
* @brief Build and apply the PWM slice configuration for 50 Hz servo
*
* Computes the clock divider from the system clock to achieve the
* target servo frequency with the chosen wrap value, then starts
* the PWM slice.
*/
static void apply_servo_config(void) {
pwm_config config = pwm_get_default_config();
// Calculate clock divider to achieve 50 Hz with our chosen wrap
const uint32_t sys_clock_hz = clock_get_hz(clk_sys);
float clock_div = (float)sys_clock_hz / (servo_hz * (servo_wrap + 1));
pwm_config_set_clkdiv(&config, clock_div);
pwm_config_set_wrap(&config, servo_wrap);
pwm_init(servo_slice, &config, true);
}
void servo_init(uint8_t pin) {
servo_pin = pin;
gpio_set_function(servo_pin, GPIO_FUNC_PWM);
servo_slice = pwm_gpio_to_slice_num(servo_pin);
servo_chan = pwm_gpio_to_channel(servo_pin);
apply_servo_config();
servo_initialized = true;
}
void servo_set_pulse_us(uint16_t pulse_us) {
if (servo_pin == 0) return; // not initialized
// clamp to defaults
if (!servo_initialized) return;
if (pulse_us < SERVO_DEFAULT_MIN_US) pulse_us = SERVO_DEFAULT_MIN_US;
if (pulse_us > SERVO_DEFAULT_MAX_US) pulse_us = SERVO_DEFAULT_MAX_US;
uint32_t level = pulse_us_to_level(pulse_us);
@@ -81,9 +101,7 @@ void servo_set_pulse_us(uint16_t pulse_us) {
void servo_set_angle(float degrees) {
if (degrees < 0.0f) degrees = 0.0f;
if (degrees > 180.0f) degrees = 180.0f;
// linear map 0..180 -> min_us..max_us
float ratio = degrees / 180.0f;
uint16_t pulse = (uint16_t)(SERVO_DEFAULT_MIN_US + ratio * (SERVO_DEFAULT_MAX_US - SERVO_DEFAULT_MIN_US) + 0.5f);
servo_set_pulse_us(pulse);
}
#
}