Fix snprintf buffer size for digit buffers

Replaces hardcoded buffer size '2' in snprintf calls with sizeof the respective digit buffer. This prevents potential buffer overflows and ensures correct string formatting for power and altitude display labels.

Author: zjwhitehead

.claude/settings.local.json

@@ -2,7 +2,8 @@
   "permissions": {
     "allow": [
       "Bash(pio)",
-      "Bash(pio run)"
+      "Bash(pio run)",
+      "Bash(cpplint:*)"
     ],
     "deny": []
   }

src/sp140/lvgl/lvgl_updates.cpp

@@ -450,19 +450,19 @@ void updateLvglMainScreen(
 
         // Tens digit (only show if >= 10kW)
         if (tens > 0) {
-          snprintf(power_digit_buffers[0], 2, "%d", tens);
+          snprintf(power_digit_buffers[0], sizeof(power_digit_buffers[0]), "%d", tens);
           lv_label_set_text(power_char_labels[0], power_digit_buffers[0]);
         }
 
         // Ones digit (always show)
-        snprintf(power_digit_buffers[1], 2, "%d", ones);
+        snprintf(power_digit_buffers[1], sizeof(power_digit_buffers[1]), "%d", ones);
         lv_label_set_text(power_char_labels[1], power_digit_buffers[1]);
 
         // Decimal point
         lv_label_set_text(power_char_labels[2], ".");
 
         // Tenths digit
-        snprintf(power_digit_buffers[3], 2, "%d", decimal_part);
+        snprintf(power_digit_buffers[3], sizeof(power_digit_buffers[3]), "%d", decimal_part);
         lv_label_set_text(power_char_labels[3], power_digit_buffers[3]);
 
         // Unit label is static and already set to "kW"
@@ -545,31 +545,31 @@ void updateLvglMainScreen(
 
       // Thousands digit
       if (thousands > 0) {
-        snprintf(digit_buffers[0], 2, "%d", thousands);
+        snprintf(digit_buffers[0], sizeof(digit_buffers[0]), "%d", thousands);
         lv_label_set_text(altitude_char_labels[0], digit_buffers[0]);
       }
 
       // Hundreds digit
       if (thousands > 0 || hundreds > 0) {
-        snprintf(digit_buffers[1], 2, "%d", hundreds);
+        snprintf(digit_buffers[1], sizeof(digit_buffers[1]), "%d", hundreds);
         lv_label_set_text(altitude_char_labels[1], digit_buffers[1]);
       }
 
       // Tens digit
       if (whole_part >= 10) {
-        snprintf(digit_buffers[2], 2, "%d", tens);
+        snprintf(digit_buffers[2], sizeof(digit_buffers[2]), "%d", tens);
         lv_label_set_text(altitude_char_labels[2], digit_buffers[2]);
       }
 
       // Ones digit (always show)
-      snprintf(digit_buffers[3], 2, "%d", ones);
+      snprintf(digit_buffers[3], sizeof(digit_buffers[3]), "%d", ones);
       lv_label_set_text(altitude_char_labels[3], digit_buffers[3]);
 
       // Decimal point
       lv_label_set_text(altitude_char_labels[4], ".");
 
       // Tenths digit
-      snprintf(digit_buffers[5], 2, "%d", decimal_part);
+      snprintf(digit_buffers[5], sizeof(digit_buffers[5]), "%d", decimal_part);
       lv_label_set_text(altitude_char_labels[5], digit_buffers[5]);
 
       // Adjust width of position 4 back to narrow for meters (decimal point)
@@ -614,30 +614,30 @@ void updateLvglMainScreen(
 
       // Ten-thousands digit in position 0
       if (ten_thousands > 0) {
-        snprintf(digit_buffers_ft[0], 2, "%d", ten_thousands);
+        snprintf(digit_buffers_ft[0], sizeof(digit_buffers_ft[0]), "%d", ten_thousands);
         lv_label_set_text(altitude_char_labels[0], digit_buffers_ft[0]);
       }
 
       // Thousands digit in position 1
       if (ten_thousands > 0 || thousands > 0) {
-        snprintf(digit_buffers_ft[1], 2, "%d", thousands);
+        snprintf(digit_buffers_ft[1], sizeof(digit_buffers_ft[1]), "%d", thousands);
         lv_label_set_text(altitude_char_labels[1], digit_buffers_ft[1]);
       }
 
       // Hundreds digit in position 2
       if (ten_thousands > 0 || thousands > 0 || hundreds > 0) {
-        snprintf(digit_buffers_ft[2], 2, "%d", hundreds);
+        snprintf(digit_buffers_ft[2], sizeof(digit_buffers_ft[2]), "%d", hundreds);
         lv_label_set_text(altitude_char_labels[2], digit_buffers_ft[2]);
       }
 
       // Tens digit in position 3
       if (feet >= 10) {
-        snprintf(digit_buffers_ft[3], 2, "%d", tens);
+        snprintf(digit_buffers_ft[3], sizeof(digit_buffers_ft[3]), "%d", tens);
         lv_label_set_text(altitude_char_labels[3], digit_buffers_ft[3]);
       }
 
       // Ones digit in position 4 (always show) - now has normal width
-      snprintf(digit_buffers_ft[4], 2, "%d", ones);
+      snprintf(digit_buffers_ft[4], sizeof(digit_buffers_ft[4]), "%d", ones);
       lv_label_set_text(altitude_char_labels[4], digit_buffers_ft[4]);
 
       // Feet unit in position 6 (same as meters, with proper spacing)

src/sp140/system_monitors.cpp

@@ -20,8 +20,7 @@ void addInternalMonitors() {
 
 void addAltimeterMonitors() {
   // Barometer Temperature monitor disabled for now.
-  // TODO:
-  // The BMP barometer shares the I2C bus with other peripherals; without a
+  // TODO: The BMP barometer shares the I2C bus with other peripherals; without a
   // global I2C mutex the `Wire` driver can log "Unfinished Repeated Start"
   // errors when transactions from multiple tasks interleave.  Until we
   // introduce a proper mutex (or move barometer access into a dedicated

src/sp140/vibration_pwm.cpp

@@ -2,7 +2,7 @@
 #include "sp140/esp32s3-config.h"
 #include "sp140/lvgl/lvgl_updates.h"
 
-const int VIBE_PWM_PIN = 46;  // TODO: move to config
+// Pin is configured via s3_config.vibe_pwm
 const int VIBE_PWM_FREQ = 1000;  // Adjust as needed
 const int VIBE_PWM_RESOLUTION = 8;  // 8-bit resolution