usb_microphone: Add serial ID

Add serial ID number to the USB microphone example using function
pico_get_unique_board_id_string from library pico_unique_id.

Signed-off-by: Leon Anavi <[email protected]>

Author: leon-anavi

CMakeLists.txt

@@ -26,7 +26,7 @@ target_include_directories(pico_pdm_microphone INTERFACE
 
 pico_generate_pio_header(pico_pdm_microphone ${CMAKE_CURRENT_LIST_DIR}/src/pdm_microphone.pio)
 
-target_link_libraries(pico_pdm_microphone INTERFACE pico_stdlib hardware_dma hardware_pio)
+target_link_libraries(pico_pdm_microphone INTERFACE pico_stdlib hardware_dma hardware_pio pico_unique_id)
 
 
 add_library(pico_analog_microphone INTERFACE)

examples/usb_microphone/usb_descriptors.c

@@ -111,13 +111,16 @@ uint8_t const * tud_descriptor_configuration_cb(uint8_t index)
 // String Descriptors
 //--------------------------------------------------------------------+
 
+// buffer to hold flash ID
+char serial[2 * PICO_UNIQUE_BOARD_ID_SIZE_BYTES + 1];
+
 // array of pointer to string descriptors
 char const* string_desc_arr [] =
 {
     (const char[]) { 0x09, 0x04 }, 	// 0: is supported language is English (0x0409)
     "PaniRCorp",                   	// 1: Manufacturer
     "MicNode",              		// 2: Product
-    "123456",                      	// 3: Serials, should use chip ID
+    serial,                      	// 3: Serials, should use chip ID
     "UAC2",                 	 	// 4: Audio Interface
 };
 
@@ -137,6 +140,9 @@ uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
     chr_count = 1;
   }else
   {
+    // Get unique ID in string format
+    if (index == 3) pico_get_unique_board_id_string(serial, sizeof(serial));
+
     // Convert ASCII string into UTF-16
 
     if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;