Optional task mutex

idf_component.yml

@@ -1,4 +1,4 @@
-version: "3.2.1"
+version: "3.2.2"
 description: "Library for communication with RFID / NFC cards using MFRC522 module"
 url: "https://github.com/abobija/esp-idf-rc522"
 repository: "https://github.com/abobija/esp-idf-rc522.git"

include/rc522_types.h

@@ -3,6 +3,7 @@
 #include <esp_err.h>
 #include <esp_event.h>
 #include <inttypes.h>
+#include "freertos/FreeRTOS.h"
 #include "rc522_driver.h"
 #include "rc522_picc.h"
 
@@ -33,9 +34,10 @@ typedef struct rc522 *rc522_handle_t;
 typedef struct
 {
     rc522_driver_handle_t driver;
-    uint16_t poll_interval_ms; /*<! Delay (in milliseconds) between polls */
-    size_t task_stack_size;    /*<! Stack size of rc522 task */
-    uint8_t task_priority;     /*<! Priority of rc522 task */
+    uint16_t poll_interval_ms;    /*<! Delay (in milliseconds) between polls */
+    size_t task_stack_size;       /*<! Stack size of rc522 task */
+    uint8_t task_priority;        /*<! Priority of rc522 task */
+    SemaphoreHandle_t task_mutex; /*<! Mutex for rc522 task */
 } rc522_config_t;
 
 typedef enum

src/rc522.c

@@ -212,10 +212,21 @@ void rc522_task(void *arg)
     const uint32_t task_delay_ms = 50;
     const uint32_t picc_heartbeat_failure_threshold_ms = (2 * task_delay_ms);
     uint32_t picc_heartbeat_failure_at_ms = 0;
+    bool mutex_taken = false;
+    const uint16_t mutex_take_timeout_ms = 4000;
 
     xEventGroupClearBits(rc522->bits, RC522_TASK_STOPPED_BIT);
 
     while (!rc522->exit_requested) {
+        if (mutex_taken && rc522->config->task_mutex != NULL) {
+            if (xSemaphoreGive(rc522->config->task_mutex) == pdTRUE) {
+                mutex_taken = false;
+            }
+            else {
+                RC522_LOGW("failed to give mutex");
+            }
+        }
+
         if (rc522->state != RC522_STATE_POLLING) {
             // waiting for state change to polling
             rc522_delay_ms(100);
@@ -224,6 +235,16 @@ void rc522_task(void *arg)
 
         rc522_delay_ms(task_delay_ms);
 
+        if (rc522->config->task_mutex != NULL) {
+            if (xSemaphoreTake(rc522->config->task_mutex, pdMS_TO_TICKS(mutex_take_timeout_ms)) == pdTRUE) {
+                mutex_taken = true;
+            }
+            else {
+                RC522_LOGW("failed to take mutex in %d ms", mutex_take_timeout_ms);
+                continue;
+            }
+        }
+
         bool should_poll = (rc522_millis() - last_poll_ms) > rc522->config->poll_interval_ms;
 
         if (rc522->picc.state == RC522_PICC_STATE_IDLE || rc522->picc.state == RC522_PICC_STATE_HALT) {