Merge branch 'feat/lower_the_audio_gain' into 'master'

feat(adc_mic): add adc mic apply gain config

See merge request ae_group/esp-iot-solution!1291

Author: lijunru-hub

components/audio/adc_mic/CHANGELOG.md

@@ -0,0 +1,13 @@
+# ChangeLog
+
+## v0.2.0 - 2024-05-22
+
+### Enhancements:
+
+* Add config ADC_MIC_APPLY_GAIN to apply gain to the ADC mic.
+
+## v0.1.0 - 2024-05-22
+
+### Enhancements:
+
+* Initial version.

components/audio/adc_mic/Kconfig

@@ -0,0 +1,23 @@
+menu "ADC Mic"
+
+    config ADC_MIC_APPLY_GAIN
+        int "Apply Gain"
+        default 3
+        range 0 4
+        help
+            Apply gain to the ADC mic.
+            0: No gain applied
+            1: Left shift 1 bit (2x gain)
+            2: Left shift 2 bits (4x gain)
+            3: Left shift 3 bits (8x gain)
+            4: Left shift 4 bits (16x gain)
+
+    config ADC_MIC_OFFSET
+        int
+        default 2048 if ADC_MIC_APPLY_GAIN = 0
+        default 4095 if ADC_MIC_APPLY_GAIN = 1
+        default 8190 if ADC_MIC_APPLY_GAIN = 2
+        default 16380 if ADC_MIC_APPLY_GAIN = 3
+        default 32760 if ADC_MIC_APPLY_GAIN = 4
+
+endmenu

components/audio/adc_mic/adc_mic.c

@@ -138,7 +138,7 @@ static int _adc_data_read(const audio_codec_data_if_t *h, uint8_t *data, int siz
         for (int i = 0; i < item_count; i++) {
             uint16_t raw_value = buffer[i].val;
             // Left shift to amplify audio.
-            p[i] = (raw_value << 4) - 32768;
+            p[i] = (raw_value << CONFIG_ADC_MIC_APPLY_GAIN) - CONFIG_ADC_MIC_OFFSET;
         }
 
         cnt += ret_num;
@@ -154,7 +154,7 @@ static int _adc_data_read(const audio_codec_data_if_t *h, uint8_t *data, int siz
         for (int i = 0; i < item_count; i++) {
             uint16_t raw_value = buffer[i].val & 0xFFFF;
             // Left shift to amplify audio.
-            p[i] = (raw_value << 4) - 32768;
+            p[i] = (raw_value << CONFIG_ADC_MIC_APPLY_GAIN) - CONFIG_ADC_MIC_OFFSET;
         }
         cnt += ret_num / 2;
         left_size -= ret_num / 2;

components/audio/adc_mic/idf_component.yml

@@ -1,4 +1,4 @@
-version: "0.1.0"
+version: "0.2.0"
 description: ADC mic input driver for ESP32 Series socs
 url: https://github.com/espressif/esp-iot-solution/tree/master/components/audio/adc_mic
 repository: https://github.com/espressif/esp-iot-solution.git