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

0x001a_operators/0x001a_operators.c

@@ -1,36 +1,126 @@
+/**
+ * @file 0x001a_operators.c
+ * @brief Operators: demonstrate C operators with DHT11 temperature sensor
+ * @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 arithmetic, increment, relational, logical, bitwise, and
+ * assignment operators in C. Also reads humidity and temperature from a
+ * DHT11 sensor on GPIO4.
+ *
+ * Wiring:
+ *   GPIO4 -> DHT11 data pin (with 10k pull-up to 3V3)
+ *   3V3   -> DHT11 VCC
+ *   GND   -> DHT11 GND
+ */
+
 #include <stdio.h>
 #include "pico/stdlib.h"
 #include "dht11.h"
 
+/**
+ * @brief Print pre-computed operator results
+ *
+ * @details Prints all six operator demonstration values over UART.
+ *
+ * @param arith   arithmetic operator result
+ * @param inc     increment operator result
+ * @param rel     relational operator result
+ * @param logic   logical operator result
+ * @param bitw    bitwise operator result
+ * @param assign  assignment operator result
+ * @retval None
+ */
+static void print_operator_results(int arith, int inc, bool rel,
+                                    bool logic, int bitw, int assign) {
+    printf("arithmetic_operator: %d\r\n", arith);
+    printf("increment_operator: %d\r\n", inc);
+    printf("relational_operator: %d\r\n", rel);
+    printf("logical_operator: %d\r\n", logic);
+    printf("bitwise_operator: %d\r\n", bitw);
+    printf("assignment_operator: %d\r\n", assign);
+}
+
+/**
+ * @brief Compute arithmetic and increment operator results
+ *
+ * @param arith pointer to store multiplication result
+ * @param incr  pointer to store post-increment result
+ * @param x     left operand
+ * @param y     right operand
+ * @retval None
+ */
+static void compute_arithmetic_ops(int *arith, int *incr, int x, int y) {
+    *arith = (x * y);
+    *incr = x++;
+}
+
+/**
+ * @brief Compute all operator values and print results
+ *
+ * @details Performs arithmetic, relational, logical, bitwise,
+ *          and assignment operations, then prints each result.
+ *
+ * @retval None
+ */
+static void compute_operators(void) {
+    int x = 5, y = 10;
+    int arith, incr;
+    compute_arithmetic_ops(&arith, &incr, x, y);
+    bool rel = (x > y);
+    bool logic = (x > y) && (y > x);
+    int bits = (x << 1);
+    int assign = (x += 5);
+    print_operator_results(arith, incr, rel, logic, bits, assign);
+}
+
+/**
+ * @brief Read and print DHT11 humidity and temperature
+ *
+ * @details Attempts a DHT11 read; on success prints humidity and
+ *          temperature, on failure prints an error message.
+ *
+ * @retval None
+ */
+static void print_dht11_reading(void) {
+    float hum, temp;
+    if (dht11_read(&hum, &temp)) {
+        printf("Humidity: %.1f%%, Temperature: %.1f°C\r\n", hum, temp);
+    } else {
+        printf("DHT11 read failed\r\n");
+    }
+}
+
 int main(void) {
     stdio_init_all();
-
     dht11_init(4);
-
-    int x = 5;
-    int y = 10;
-    int arithmetic_operator = (x * y);
-    int increment_operator = x++;
-    bool relational_operator = (x > y);
-    bool logical_operator = (x > y) && (y > x);
-    int bitwise_operator = (x<<1);  // x is now 6 because of x++ or 0b00000110 and (x<<1) is 0b00001100 or 12 
-    int assignment_operator = (x += 5);
-
     while (true) {
-        printf("arithmetic_operator: %d\r\n", arithmetic_operator);
-        printf("increment_operator: %d\r\n", increment_operator);
-        printf("relational_operator: %d\r\n", relational_operator);
-        printf("logical_operator: %d\r\n", logical_operator);
-        printf("bitwise_operator: %d\r\n", bitwise_operator);
-        printf("assignment_operator: %d\r\n", assignment_operator);
-        
-        float hum, temp;
-        if (dht11_read(&hum, &temp)) {
-            printf("Humidity: %.1f%%, Temperature: %.1f°C\r\n", hum, temp);
-        } else {
-            printf("DHT11 read failed\r\n");
-        }
-        
+        compute_operators();
+        print_dht11_reading();
         sleep_ms(2000);
     }
 }