From 77724a6d9a1f5bf8db690b39c608843974f65fcd Mon Sep 17 00:00:00 2001
From: whowechina <whowechina@gmail.com>
Date: Tue, 10 Oct 2023 22:34:08 +0800
Subject: [PATCH] Use pico's board id as USB SN

---
 firmware/src/CMakeLists.txt    |  2 +-
 firmware/src/usb_descriptors.c | 14 +++++++++++---
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/firmware/src/CMakeLists.txt b/firmware/src/CMakeLists.txt
index 574aca1..2685fa6 100644
--- a/firmware/src/CMakeLists.txt
+++ b/firmware/src/CMakeLists.txt
@@ -20,7 +20,7 @@ function(make_firmware board board_def)
     
     target_link_libraries(${board} PRIVATE
         pico_multicore pico_stdlib hardware_pio hardware_pwm hardware_flash
-        hardware_adc hardware_i2c hardware_watchdog
+        hardware_adc hardware_i2c hardware_watchdog pico_unique_id
         tinyusb_device tinyusb_board)
 
     pico_add_extra_outputs(${board})
diff --git a/firmware/src/usb_descriptors.c b/firmware/src/usb_descriptors.c
index 8a9fc3f..eb601d1 100644
--- a/firmware/src/usb_descriptors.c
+++ b/firmware/src/usb_descriptors.c
@@ -24,7 +24,7 @@
  */
 
 #include "usb_descriptors.h"
-
+#include "pico/unique_id.h"
 #include "tusb.h"
 
 /* A combination of interfaces must have a unique product id, since PC will save
@@ -173,12 +173,14 @@ uint8_t const* tud_descriptor_configuration_cb(uint8_t index) {
 // String Descriptors
 //--------------------------------------------------------------------+
 
+static char serial_number_str[24] = "123456\0";
+
 // array of pointer to string descriptors
-const char *string_desc_arr[] = {
+static const char *string_desc_arr[] = {
     (const char[]){0x09, 0x04},  // 0: is supported language is English (0x0409)
     "WHowe"       ,              // 1: Manufacturer
     "Mai Pico Controller",       // 2: Product
-    "123456",                    // 3: Serials, should use chip ID
+    serial_number_str,           // 3: Serials, use chip ID
     "Mai Pico Joystick",
     "Mai Pico LED",
     "Mai Pico NKRO",
@@ -200,6 +202,12 @@ uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid)
         return _desc_str;
     }
     
+    if (index == 3) {
+        pico_unique_board_id_t board_id;
+        pico_get_unique_board_id(&board_id);
+        sprintf(serial_number_str, "%016llx", board_id);
+    }
+    
     const size_t base_num = sizeof(string_desc_arr) / sizeof(string_desc_arr[0]);
     const char *colors[] = {"Blue", "Red", "Green"};
     char str[64];