firmware: Move serial number code to main

firmware/main/common.h

@@ -9,5 +9,7 @@
 #define LCD_HRES        800
 #define LCD_VRES        480
 
+extern char val_dev_serial[13];
+
 extern i2c_master_bus_handle_t i2c_bus_handle;
 extern i2c_master_dev_handle_t exio_cfg_handle, exio_o_handle;

firmware/main/usb.c

@@ -1,7 +1,6 @@
 #include <inttypes.h>
 
 #include "esp_log.h"
-#include "esp_mac.h"
 
 #include "tinyusb.h"
 #include "class/hid/hid_device.h"
@@ -38,7 +37,6 @@ const tusb_desc_device_t val_usb_dev_descriptor = {
   .bNumConfigurations = 0x01,
 };
 
-char val_dev_serial[13];
 const char* val_usb_string_descriptor[5] = {
   // 0: supported language is English (0x0409)
   (char[]){0x09, 0x04},
@@ -101,13 +99,6 @@ void tud_hid_set_report_cb(uint8_t instance, uint8_t report_id, hid_report_type_
 void val_usb_init(void) {
   ESP_LOGI(TAG, "Initializing USB");
 
-  // Use MAC address for serial number
-  uint8_t mac[6] = { 0 };
-  ESP_ERROR_CHECK(esp_read_mac(mac, ESP_MAC_EFUSE_FACTORY));
-  snprintf(
-    val_dev_serial, sizeof(val_dev_serial),
-    "%02x%02x%02x%02x%02x%02x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
-
   const tinyusb_config_t cfg = {
     .device_descriptor = &val_usb_dev_descriptor,
     .string_descriptor = val_usb_string_descriptor,

firmware/main/valconomy.c

@@ -6,6 +6,7 @@
 
 #include "esp_err.h"
 #include "esp_log.h"
+#include "esp_mac.h"
 #include "esp_lcd_panel_ops.h"
 #include "driver/i2c_master.h"
 
@@ -18,6 +19,8 @@
 
 static const char *TAG = "valconomy";
 
+char val_dev_serial[13];
+
 i2c_master_bus_handle_t i2c_bus_handle;
 i2c_master_dev_handle_t exio_cfg_handle, exio_o_handle;
 
@@ -46,6 +49,13 @@ static void val_i2c_master_init(void) {
 }
 
 void app_main(void) {
+  // Use MAC address for serial number
+  uint8_t mac[6] = { 0 };
+  ESP_ERROR_CHECK(esp_read_mac(mac, ESP_MAC_EFUSE_FACTORY));
+  snprintf(
+    val_dev_serial, sizeof(val_dev_serial),
+    "%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+
   val_i2c_master_init();
 
   val_usb_init();