Add M1 single-shot temp query command; NTC trimmed-mean filter

Src/ntc.c

@@ -46,13 +46,30 @@ static uint16_t ntc_read_raw_once(void) {
 }
 
 float ntc_read_temperature(void) {
+    uint16_t samples[NTC_SAMPLE_COUNT];
     uint32_t sum = 0U;
 
-    /* 多次采样均值降噪 */
+    /* 采集 NTC_SAMPLE_COUNT 个样本 */
     for (uint8_t i = 0; i < NTC_SAMPLE_COUNT; i++) {
-        sum += ntc_read_raw_once();
+        samples[i] = ntc_read_raw_once();
     }
-    float adc_val = (float)sum / (float)NTC_SAMPLE_COUNT;
+
+    /* 插入排序（16 元素，开销可忽略），为修剪均值做准备 */
+    for (uint8_t i = 1; i < NTC_SAMPLE_COUNT; i++) {
+        uint16_t key = samples[i];
+        int8_t j = (int8_t)(i - 1);
+        while (j >= 0 && samples[j] > key) {
+            samples[j + 1] = samples[j];
+            j--;
+        }
+        samples[j + 1] = key;
+    }
+
+    /* 修剪均值：去掉每端 NTC_TRIM_COUNT 个极值（野值/毛刺）后取平均 */
+    for (uint8_t i = NTC_TRIM_COUNT; i < (NTC_SAMPLE_COUNT - NTC_TRIM_COUNT); i++) {
+        sum += samples[i];
+    }
+    float adc_val = (float)sum / (float)(NTC_SAMPLE_COUNT - 2U * NTC_TRIM_COUNT);
 
     /* 分压点电压：上拉 R_PULL 在 VREF 侧，NTC 接 GND 侧 */
     float voltage = adc_val * NTC_VREF / NTC_ADC_MAX;