add buzzer variant + readme

buzzer/CMakeLists.txt

@@ -62,7 +62,7 @@ pico_enable_stdio_usb(buzzer 1)
 
 # Add the standard library to the build
 target_link_libraries(buzzer
-        pico_stdlib hardware_pwm pico_multicore hardware_exception)
+        pico_stdlib hardware_pwm pico_multicore hardware_exception hardware_adc)
 
 # Add the standard include files to the build
 target_include_directories(buzzer PRIVATE

buzzer/README.md

@@ -0,0 +1,39 @@
+# buzzer
+
+
+A program to run alarm on button pushed.
+
+To activate the alarm, push the button. Same for desactivation.
+The alarm is launched in a separate task and controlled by
+the main task (which holds the push button logic).
+
+You can run the application in "DEBUG" mode using:
+`make run-debug name=buzzer`
+The FreeRTOS engine is replaced by threads. 
+
+## Hardware
+
+### Variant 1
+
+* 1x Passive Buzzer
+* 1x Push button
+* 1 NPN transistor for signal amplification
+* 1x 1k ohm resistor (NPN collector)
+* 2x 10k ohm resistor
+
+<div align="center">
+<img src="circuit.jpg" style="transform:rotate(-90deg); margin:-100px;" width="300" />
+</div>
+
+### Variant 2
+You can play with the frequency [1500; 2000] hz thanks to the potentiometer.
+
+* Variant 1
+* 1x Rotary potentiometer
+* 1x blue LED
+
+<div align="center">
+<img src="circuit_variant.jpg" style="transform:rotate(-90deg); margin:-90px;" width="300" />
+</div>
+
+Enjoy ! 😉

buzzer/gpio.c

@@ -4,8 +4,7 @@
 #include <pico/printf.h>
 #include <pico/stdlib.h>
 #include <hardware/pwm.h>
-
+#include <hardware/adc.h>
-#define DEFAULT_WRAP_LEVEL 20
 #else
 #include <stdio.h>
 #include <stdlib.h>
@@ -37,6 +36,21 @@ void _sleep_us(size_t value) {
 #endif
 }
 
+/**
+ * Returns a ratio of the ADC value input.
+ *
+ * The range of the ADC on Raspberry Pico 2 is 10 bits so the resolution is 1024 (2^10).
+ *
+ */
+double gpio_get_adc() {
+#ifdef PICO
+    return adc_read() / 1023.0 ; // 2^10 - 1
+#else
+    trace("<GPIO.get_adc (input=0) (value=?)");
+#endif
+}
+
+
 void gpio_set_level(gpio *g, uint16_t level) {
     if (g->has_pwm && g->direction == GPIO_OUT) {
         g->level = level;
@@ -44,7 +58,7 @@ void gpio_set_level(gpio *g, uint16_t level) {
 #ifdef PICO
         pwm_set_gpio_level(g->pin, level);
 #else
-        debug("<GPIO.set_level (pin=%ld) (level=%d)>", g->pin, level);
+        trace("<GPIO.set_level (pin=%ld) (level=%d)>", g->pin, level);
 #endif
     }
 }
@@ -70,7 +84,7 @@ bool gpio_get_input(gpio* g) {
         }
         g->state = GPIO_INPUT_MOCK_COUNTER++ % value == 0;
 #endif
-        trace("<GPIO.get_input (pin=%ld) (level=%d)>", g->pin, g->state);
+        trace("<GPIO.get_input (pin=%ld) (state=%d)>", g->pin, g->state);
         return g->state;
     }
     return false;
@@ -91,12 +105,15 @@ void gpio_onoff(gpio* g, uint32_t delay_ms, size_t times) {
 void init_gpio(void) {
 #ifdef PICO
     stdio_init_all();
+    adc_init();
+    adc_select_input(0); // pin: 26
     for (size_t i = 0; i < NB_GPIO; i++) {
         gpio_init(GPIOS[i]->pin);
         gpio_set_dir(GPIOS[i]->pin, GPIOS[i]->direction);
 
         if (GPIOS[i]->has_pwm) {
             uint slice_num = pwm_gpio_to_slice_num(GPIOS[i]->pin);
+            gpio_set_function(GPIOS[i]->pin, GPIO_FUNC_PWM);
             pwm_set_enabled(slice_num, true);
             pwm_set_wrap(slice_num, DEFAULT_WRAP_LEVEL);
         }

buzzer/gpio.h

@@ -22,7 +22,8 @@
 #define GPIO_IN 0
 #endif
 
-#define NB_GPIO 3
+#define NB_GPIO 5
+#define DEFAULT_WRAP_LEVEL 20
 
 typedef struct gpio gpio;
 struct gpio {
@@ -45,11 +46,20 @@ static gpio GPIO_BUZZER = (gpio) {
     .pin = 15, .direction = GPIO_OUT, .has_pwm = false, .level = 0, .state = false
 };
 
-static gpio* GPIOS[NB_GPIO] = {&GPIO_DEFAULT_LED, &GPIO_BUTTON, &GPIO_BUZZER};
+static gpio GPIO_ADC = (gpio) {
+    .pin = 26, .direction = GPIO_IN, .has_pwm = false, .level = 0, .state = false
+};
+
+static gpio GPIO_LED = (gpio) {
+    .pin = 20, .direction = GPIO_OUT, .has_pwm = true, .level = 0, .state = false
+};
+
+static gpio* GPIOS[NB_GPIO] = {&GPIO_DEFAULT_LED, &GPIO_BUTTON, &GPIO_BUZZER, &GPIO_ADC, &GPIO_LED};
 
 void gpio_set_level(gpio *g, uint16_t level);
 void gpio_set_state(gpio *g, bool state);
 bool gpio_get_input(gpio* g);
+double gpio_get_adc(void);
 void gpio_onoff(gpio* g, uint32_t delay_ms, size_t times);
 
 void init_gpio(void);

buzzer/jobs.c

@@ -29,6 +29,7 @@ int init_app_state(AppState *s) {
         return -1;
     }
 #endif
+    s->freq_multiplicator = 0;
     return 0;
 }
 
@@ -60,6 +61,7 @@ int cancel_task(AppState *s) {
         vTaskDelete(*s->task);
         free(s->task);
         gpio_set_state(GPIOS[2], false);
+        gpio_set_level(GPIOS[4],0);
         return 0;
     }
 #else
@@ -76,6 +78,7 @@ int cancel_task(AppState *s) {
         free(s->task);
         s->task = NULL;
     }
+    gpio_set_level(GPIOS[4],0);
     return 0;
 #endif
 }
@@ -91,8 +94,8 @@ int launch_task(AppState *s, FnJob f) {
     }
 
     BaseType_t res =
-        xTaskCreate(f, "task", configMINIMAL_STACK_SIZE,
+        xTaskCreateAffinitySet(f, "task", configMINIMAL_STACK_SIZE,
-                    NULL, configMAX_PRIORITIES - 1U, task);
+                               s, configMAX_PRIORITIES - 1U, 1 << 1,task);
 
     if (res != pdPASS) {
         error("unable to launch run alarm task task, code error: %d",
@@ -117,6 +120,37 @@ int launch_task(AppState *s, FnJob f) {
     return 0;
 }
 
+/**
+ *
+ */
+void check_acd_value(void* args) {
+    AppState* s = (AppState*) args;
+    uint16_t current_freq_multiplicator = 0;
+
+    for (;;) {
+        double freq_mul = gpio_get_adc();
+        if (freq_mul != current_freq_multiplicator) {
+#ifdef PICO
+            gpio_set_level(GPIOS[4], current_freq_multiplicator * DEFAULT_WRAP_LEVEL);
+#endif
+
+            if (lock(s) != 0)
+                fatal(stop_app_fallback, "unable to lock app mutex");
+
+            s->freq_multiplicator = freq_mul;
+            current_freq_multiplicator = freq_mul;
+
+            if (release(s) != 0)
+                fatal(stop_app_fallback, "unable to release app mutex");
+
+            debug("freq multiplicator updated: %d\n", current_freq_multiplicator);
+        }
+#ifdef PICO
+        gpio_set_level(GPIOS[4], current_freq_multiplicator * DEFAULT_WRAP_LEVEL);
+#endif
+    }
+}
+
 /**
  * Main app loop.
  *

buzzer/jobs.h

@@ -17,6 +17,7 @@ enum ACTION {STOP, START};
 typedef struct AppState AppState;
 struct AppState {
     Action action;
+    double freq_multiplicator;
     
     #ifdef PICO
         TaskHandle_t* task;
@@ -38,6 +39,7 @@ struct TaskParam {
 int init_app_state(AppState *s);
 
 void check_btn_state(void* args);
+void check_acd_value(void* args);
 
 int lock(AppState *s);
 int release(AppState *s);

buzzer/main.c

@@ -24,8 +24,8 @@
 #include "gpio.h"
 #include "utils.h"
 
-#define ALARM_BASE_FREQ 2000 // auditive frequency human range: [20; 20000] hertz
+#define ALARM_BASE_FREQ 1500 // auditive frequency human range: [20; 20000] hertz
-#define ALARM_PERIOD_MS 500
+#define ALARM_PERIOD_MS 200
 #define PI 3.14
 
 /**
@@ -35,7 +35,8 @@
  *
  * NOTE: `sleep_us` method does not impact FreeRTOS engine
  * since, the scheduler started on two cores (RP2350). The behavior may differs
- * on one core. Update the FreeRTOS tick freq and implement `pdUS_TO_TICKS` if needed.
+ * on one core. Update the FreeRTOS tick freq and implement `pdUS_TO_TICKS` if needed or,
+ * run the alarm in dedicated core see: `xTaskCreateAffinitySet`.
  */
 void gen_freq(gpio* g, size_t freq_hz, size_t duration_ms) {
     if (!freq_hz) {
@@ -59,7 +60,22 @@ void gen_freq(gpio* g, size_t freq_hz, size_t duration_ms) {
 }
 
 void run_alarm(void *const params) {
+    AppState* as = (AppState* ) params;
+
     for(;;) {
+        if (lock(as) != 0)
+            fatal(stop_app_fallback, "unable to lock the app state");
+
+        uint16_t freq = as->freq_multiplicator * 500 + ALARM_BASE_FREQ;
+
+        if (release(as) != 0)
+            fatal(stop_app_fallback, "unable to release the app state");
+
+
+#ifdef PICO
+        gpio_set_level(GPIOS[4], as->freq_multiplicator * DEFAULT_WRAP_LEVEL);
+#endif
+
         debug("running alarm...");
         float sin_val;
         int tone_val;
@@ -68,18 +84,37 @@ void run_alarm(void *const params) {
 
         for (size_t i = 0; i < 360; i+=10) {
             sin_val = sinf(i * (PI / 180));
-            tone_val = ALARM_BASE_FREQ + sin_val * (ALARM_BASE_FREQ / 10);
+            tone_val = freq  + sin_val * (freq / 10);
             gen_freq(GPIOS[2], tone_val, duration_ms);
         }
     }
 }
 
+int init_check_adc_value(AppState* as) {
+#ifdef PICO
+    BaseType_t res =
+        xTaskCreateAffinitySet(check_acd_value, "check_adc_value", configMINIMAL_STACK_SIZE,
+                               (void *const)as, configMAX_PRIORITIES - 1U, 1 << 0, NULL);
+
+    if (res != pdPASS)
+        return -1;
+
+    return 0;
+#else
+    pthread_t task;
+    if (pthread_create(&task, NULL, check_acd_value, as) != 0) {
+        return -1;
+    }
+    return 0;
+#endif
+}
+
 // Initialize the main FreeRTOS task.
 int init_rtos_main(TaskParam *params) {
 #ifdef PICO
     BaseType_t res =
-        xTaskCreate(check_btn_state, "main", configMINIMAL_STACK_SIZE,
+        xTaskCreateAffinitySet(check_btn_state, "main", configMINIMAL_STACK_SIZE,
-                    (void *const)params, configMAX_PRIORITIES - 1U, NULL);
+                               (void *const)params, configMAX_PRIORITIES - 1U, 1 << 0, NULL);
 
     if (res != pdPASS)
         return -1;
@@ -105,9 +140,14 @@ int init_rtos_main(TaskParam *params) {
  * You can run the application in "DEBUG" mode using:
  * `make run-debug name=buzzer`
  * The FreeRTOS engine is replaced by threads.
+ *
+ * A variant to play with the frequency can be done adding a
+ * potentiometer and set `check_adc` to true. See README.md for details.
+ *
  */
 int main() {
     init_gpio();
+    bool check_adc = false;
 
     AppState as;
     if (init_app_state(&as)  != 0)
@@ -118,6 +158,11 @@ int main() {
         .f = run_alarm,
     };
 
+    // launch the check of the ADC value reveived by the potentiometer
+    if (check_adc)
+        if (init_check_adc_value(&as) != 0)
+            fatal(stop_app_fallback, "unable to launch check adc value task");
+
 #ifdef PICO
     if (init_rtos_main(&params) != 0)
         fatal(stop_app_fallback, "unable to launch to FreeRTOS main task");