c version of exercise

c/CMakeLists.txt

@@ -9,3 +9,6 @@ add_subdirectory(test-cmocka)
 add_subdirectory(test-catch2)
 add_subdirectory(test-cgreen)
 add_subdirectory(test-gtest)
+
+add_executable(main main.c)
+target_link_libraries(main src)

c/main.c

@@ -0,0 +1,22 @@
+#include "stepper.h"
+#include <unistd.h>
+
+int main(int argc, char *argv[]) {
+
+    // create an instance of the stepper class with suitable pins set up
+    struct Stepper_t* stepper = stepper_create();
+
+    // configure the stepper motor speed in RPM
+    setSpeed(stepper, 10);
+
+    // move the motor the number of steps indicated by val
+    int16_t val = 42;
+    move_clockwise(stepper, val);
+
+    // wait for the stepper motor to finish moving
+    while(isRunning(stepper)) {
+        sleep(1);
+    }
+
+}
+

c/src/CMakeLists.txt

@@ -1,5 +1,7 @@
 set(SRC_LIB_NAME src)
-set(SOURCES sample.c)
+set(SOURCES
+        stepper.h
+        stepper.c)
 add_library(${SRC_LIB_NAME} ${SOURCES})
 target_sources(${SRC_LIB_NAME} PRIVATE ${SOURCES})
 target_include_directories(${SRC_LIB_NAME} PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})

c/src/stepper.c

@@ -0,0 +1,35 @@
+#include "stepper.h"
+
+#include <stdlib.h>
+
+struct Stepper_t *stepper_create() {
+    int8_t pin1 = 8;
+    int8_t pin2 = 9;
+    int8_t pin3 = 10;
+    int8_t pin4 = 1;
+    return stepper_create_with_pins(pin1, pin2, pin3, pin4);
+}
+
+struct Stepper_t * stepper_create_with_pins(const int8_t pin1, const int8_t pin2, const int8_t pin3, const int8_t pin4) {
+    struct Stepper_t* stepper = malloc(sizeof(*stepper));
+    // logic related to the pins is omitted in this exercise
+    stepper->speed = 10;
+    return stepper;
+}
+
+void setSpeed(struct Stepper_t *stepper, int8_t speed) {
+    stepper->speed = speed;
+}
+
+void move_clockwise(struct Stepper_t *stepper, int16_t steps) {
+    // logic to activate the relevant pins is omitted in this exercise
+}
+
+void move_anticlockwise(struct Stepper_t *stepper, int16_t steps) {
+    // logic to activate the relevant pins is omitted in this exercise
+}
+
+bool isRunning(struct Stepper_t *stepper) {
+    // logic to read the pins and determine this omitted in this exercise
+    return false;
+}

c/src/stepper.h

@@ -0,0 +1,40 @@
+#ifndef STEPPER_H
+#define STEPPER_H
+
+#include <stdbool.h>
+#include <unistd.h>
+
+// the number of steps to rotate a complete circle of 360 degrees
+#define STEPS 2048
+
+// the maximum speed of the motor in RPM
+#define MAX_SPEED 15
+
+/*
+ * This struct is a placeholder for a real object that would be able to
+ * control an electric stepper motor.
+ */
+struct Stepper_t {
+    int8_t speed;
+};
+
+struct Stepper_t *stepper_create_with_pins(
+    int8_t pin1,
+    int8_t pin2,
+    int8_t pin3,
+    int8_t pin4);
+
+struct Stepper_t *stepper_create();
+
+// Set the speed of the motor in RPM. Maximum is defined above.
+void setSpeed(struct Stepper_t* stepper, int8_t speed);
+
+// Move the indicated number of steps. The size of a step is defined above.
+void move_clockwise(struct Stepper_t* stepper, int16_t steps);
+void move_anticlockwise(struct Stepper_t* stepper, int16_t steps);
+
+// Whether the motor is currently moving.
+// Motors that are moving should not be given new instructions.
+bool isRunning(struct Stepper_t* stepper);
+
+#endif //STEPPER_H

c/test-catch2/sample_catch.cpp

@@ -3,13 +3,13 @@
 
 extern "C"
 {
-#include "sample.h"
+#include "stepper.h"
 }
 
 
 TEST_CASE ("Sample") {
     SECTION("sample section") {
-        REQUIRE(42 == add(1,2));
+        REQUIRE(42 == 0);
     }
 }
 

c/test-cmocka/CMakeLists.txt

@@ -42,5 +42,3 @@ endfunction()
 
 
 add_subdirectory(simple_test)
-add_subdirectory(sample_test)
-add_subdirectory(uptime)