Update to version 1.8.1.

Author: AlexRogersCS

src/audioConfig.c

@@ -54,7 +54,11 @@
 
 #define VCO_GAIN                            0.5f
 
-#define AGC_FILTER_CUTOFF_FREQUENCY         20
+#define USE_AGC                             true
+#define MANUAL_GAIN_DIVISOR                 5000.0f
+#define AGC_MINIMUM_AMPLITUDE               100.0f
+#define AGC_FILTER_CUTOFF_FREQUENCY         1000
+
 #define CHANNEL_FILTER_CUTOFF_FREQUENCY     100
 #define CHANNEL_FILTER_BANDWIDTH            2.0f
 #define CARRIER_FILTER_CUTOFF_FREQUENCY     1000
@@ -75,6 +79,8 @@
 
 #define MIN(a, b)                           ((a) < (b) ? (a) : (b))
 
+#define MAX(a, b)                           ((a) > (b) ? (a) : (b))
+
 /* Sine table */
 
 static const float sineTable[SINE_TABLE_LENGTH] = {0.000000000000f, 0.024541229010f, 0.049067676067f, 0.073564566672f, 0.098017141223f, 0.122410677373f, 0.146730467677f, 0.170961901546f, \
@@ -150,7 +156,7 @@ static BQ_filterCoefficients_t channelFilterCoefficients;
 
 /* Carrier generation variable */
 
-float omegaT = 0.0f;
+static float omegaT = 0.0f;
 
 /* Configuration variables */
 
@@ -170,7 +176,7 @@ typedef enum {NONE, HIGH_BIT, LOW_BIT} receivedBit_t;
 
 /* CRC functions */
 
-static uint16_t updateCRC(uint16_t crc_in, int incr) {
+static inline uint16_t updateCRC(uint16_t crc_in, int incr) {
 
     uint16_t xor = crc_in >> 15;
     uint16_t out = crc_in << 1;
@@ -187,7 +193,7 @@ static uint16_t updateCRC(uint16_t crc_in, int incr) {
 
 }
 
-static uint16_t calculateCRC(const uint8_t *data, uint32_t size) {
+static inline uint16_t calculateCRC(const uint8_t *data, uint32_t size) {
 
     uint16_t crc, i;
 
@@ -205,7 +211,7 @@ static uint16_t calculateCRC(const uint8_t *data, uint32_t size) {
 
 }
 
-static bool checkCRC(const uint8_t *data, uint32_t size) {
+static inline bool checkCRC(const uint8_t *data, uint32_t size) {
 
     uint16_t crc = calculateCRC(data, size - CRC_SIZE_IN_BYTES);
 
@@ -218,15 +224,25 @@ static bool checkCRC(const uint8_t *data, uint32_t size) {
 
 /* Function to perform Costas loop */
 
-float updateCostasLoop(float sample) {
+static inline float updateCostasLoop(float sample) {
 
     /* Apply gain control */
 
     float filteredSample = Butterworth_applyBandPassFilter(sample, &carrierFilter, &carrierFilterCoefficients);
 
-    float agcOutput = Butterworth_applyLowPassFilter(filteredSample > 0 ? filteredSample : -filteredSample, &agcFilter, &agcFilterCoefficients);
+    if (USE_AGC) {
+
+        float regulatedFilteredSample = filteredSample > 0.0f ? filteredSample : -filteredSample;
+
+        float agcOutput = Butterworth_applyLowPassFilter(regulatedFilteredSample, &agcFilter, &agcFilterCoefficients);
+
+        filteredSample /= MAX(agcOutput, AGC_MINIMUM_AMPLITUDE);
 
-    if (agcOutput != 0) filteredSample /= agcOutput;
+    } else {
+
+        filteredSample /= MANUAL_GAIN_DIVISOR;
+
+    }
 
     /* Demodulate input sound */
 
@@ -258,10 +274,10 @@ float updateCostasLoop(float sample) {
 
 inline void AudioMoth_handleMicrophoneInterrupt(int16_t sample) {
 
-    configSample = sample;
-
     configSampleReady = true;
 
+    configSample = sample;
+
 }
 
 /* Functions to handle audio configuration */
@@ -272,28 +288,30 @@ void AudioConfig_enableAudioConfiguration() {
 
     AudioMoth_enableMicrophone(CONFIG_GAIN_RANGE, CONFIG_GAIN, CONFIG_CLOCK_DIVIDER, CONFIG_ACQUISITION_CYCLES, CONFIG_OVERSAMPLE_RATE);
 
-    AudioMoth_startMicrophoneSamples(CONFIG_SAMPLE_RATE);
-
-    AudioMoth_initialiseMicrophoneInterupts();
+    AudioMoth_initialiseMicrophoneInterrupts();
 
     /* Design filters */
 
-    Butterworth_designLowPassFilter(&agcFilterCoefficients, CONFIG_SAMPLE_RATE, SPEED_FACTOR * AGC_FILTER_CUTOFF_FREQUENCY);
-
     Butterworth_designBandPassFilter(&carrierFilterCoefficients, CONFIG_SAMPLE_RATE, CONFIG_CARRIER_FREQUENCY - CARRIER_FILTER_CUTOFF_FREQUENCY, CONFIG_CARRIER_FREQUENCY + CARRIER_FILTER_CUTOFF_FREQUENCY);
 
+    if (USE_AGC) Butterworth_designLowPassFilter(&agcFilterCoefficients, CONFIG_SAMPLE_RATE, SPEED_FACTOR * AGC_FILTER_CUTOFF_FREQUENCY);
+
     Biquad_designLowPassFilter(&channelFilterCoefficients, CONFIG_SAMPLE_RATE, SPEED_FACTOR * CHANNEL_FILTER_CUTOFF_FREQUENCY, CHANNEL_FILTER_BANDWIDTH);
 
     /* Initialise filters */
 
-    Butterworth_initialise(&agcFilter);
-
     Butterworth_initialise(&carrierFilter);
 
+    if (USE_AGC) Butterworth_initialise(&agcFilter);
+
     Biquad_initialise(&channel1Filter);
 
     Biquad_initialise(&channel2Filter);
 
+    /* Start the microphone samples */
+
+    AudioMoth_startMicrophoneSamples(CONFIG_SAMPLE_RATE);
+
 }
 
 void AudioConfig_disableAudioConfiguration() {
@@ -344,7 +362,7 @@ bool AudioConfig_listenForAudioConfigurationTone(uint32_t milliseconds) {
 
             /* Check thresholds */
 
-            if ((lastValue > 0 && costasLoopOutput < 0) || (lastValue < 0 && costasLoopOutput > 0)) {
+            if ((lastValue >= 0 && costasLoopOutput < 0) || (lastValue < 0 && costasLoopOutput >= 0)) {
 
                 uint32_t period = counter - lastCrossing;
 
@@ -368,20 +386,16 @@ bool AudioConfig_listenForAudioConfigurationTone(uint32_t milliseconds) {
 
             }
 
+            /* Update counters and status */
+
             lastValue = costasLoopOutput;
 
+            configSampleReady = false;
+
             counter += 1;
 
         }
 
-        /* Wait for next sample */
-
-        configSampleReady = false;
-
-        /* Sleep until next interrupt occurs */
-
-        AudioMoth_sleep();
-
     }
 
     return false;
@@ -434,7 +448,7 @@ bool AudioConfig_listenForAudioConfigurationPackets(bool timeout, uint32_t milli
 
             /* Check thresholds */
 
-            if ((lastValue > 0 && costasLoopOutput < 0) || (lastValue < 0 && costasLoopOutput > 0)) {
+            if ((lastValue >= 0 && costasLoopOutput < 0) || (lastValue < 0 && costasLoopOutput >= 0)) {
 
                 uint32_t period = counter - lastCrossing;
 
@@ -606,20 +620,16 @@ bool AudioConfig_listenForAudioConfigurationPackets(bool timeout, uint32_t milli
 
             }
 
+            /* Update counters and status */
+
             lastValue = costasLoopOutput;
 
+            configSampleReady = false;
+
             counter += 1;
 
         }
 
-        /* Wait for next sample */
-
-        configSampleReady = false;
-
-        /* Sleep until next interrupt occurs */
-
-        AudioMoth_sleep();
-
     }
 
     return cancel == false;

src/main.c

@@ -911,7 +911,7 @@ static int16_t secondaryBuffer[MAXIMUM_SAMPLES_IN_DMA_TRANSFER];
 
 /* Firmware version and description */
 
-static uint8_t firmwareVersion[AM_FIRMWARE_VERSION_LENGTH] = {1, 8, 0};
+static uint8_t firmwareVersion[AM_FIRMWARE_VERSION_LENGTH] = {1, 8, 1};
 
 static uint8_t firmwareDescription[AM_FIRMWARE_DESCRIPTION_LENGTH] = "AudioMoth-Firmware-Basic";
 
@@ -1031,7 +1031,7 @@ static GPS_fixResult_t setTimeFromGPS(bool enableLED, uint32_t timeout) {
 
 }
 
-/* Magenetic switch wait functions */
+/* Magnetic switch wait functions */
 
 static void startWaitingForMagneticSwith() {
 
@@ -2345,7 +2345,7 @@ static AM_recordingState_t makeRecording(uint32_t timeOfNextRecording, uint32_t
 
     /* Calculate time correction for sample rate due to file header */
 
-    uint32_t numberOfSamplesInHeader = sizeof(wavHeader) / NUMBER_OF_BYTES_IN_SAMPLE;
+    uint32_t numberOfSamplesInHeader = sizeof(wavHeader_t) / NUMBER_OF_BYTES_IN_SAMPLE;
 
     int32_t sampleRateTimeOffset = ROUNDED_DIV(numberOfSamplesInHeader * MILLISECONDS_IN_SECOND, effectiveSampleRate);
 
@@ -2375,7 +2375,7 @@ static AM_recordingState_t makeRecording(uint32_t timeOfNextRecording, uint32_t
 
     /* Calculate updated recording parameters */
 
-    uint32_t maximumNumberOfSeconds = (MAXIMUM_WAV_FILE_SIZE - sizeof(wavHeader)) / NUMBER_OF_BYTES_IN_SAMPLE / effectiveSampleRate;
+    uint32_t maximumNumberOfSeconds = (MAXIMUM_WAV_FILE_SIZE - sizeof(wavHeader_t)) / NUMBER_OF_BYTES_IN_SAMPLE / effectiveSampleRate;
 
     bool fileSizeLimited = (recordDuration > maximumNumberOfSeconds);
 
@@ -2469,11 +2469,11 @@ static AM_recordingState_t makeRecording(uint32_t timeOfNextRecording, uint32_t
 
                     while (numberOfBlankSamplesToWrite > 0) {
 
-                        uint32_t numberOfSmples = MIN(numberOfBlankSamplesToWrite, COMPRESSION_BUFFER_SIZE_IN_BYTES / NUMBER_OF_BYTES_IN_SAMPLE);
+                        uint32_t numberOfSamples = MIN(numberOfBlankSamplesToWrite, COMPRESSION_BUFFER_SIZE_IN_BYTES / NUMBER_OF_BYTES_IN_SAMPLE);
 
-                        FLASH_LED_AND_RETURN_ON_ERROR(AudioMoth_writeToFile(compressionBuffer, NUMBER_OF_BYTES_IN_SAMPLE * numberOfSmples));
+                        FLASH_LED_AND_RETURN_ON_ERROR(AudioMoth_writeToFile(compressionBuffer, NUMBER_OF_BYTES_IN_SAMPLE * numberOfSamples));
 
-                        numberOfBlankSamplesToWrite -= numberOfSmples;
+                        numberOfBlankSamplesToWrite -= numberOfSamples;
 
                     }
 
@@ -2554,7 +2554,7 @@ static AM_recordingState_t makeRecording(uint32_t timeOfNextRecording, uint32_t
 
     FLASH_LED_AND_RETURN_ON_ERROR(AudioMoth_seekInFile(0));
 
-    FLASH_LED_AND_RETURN_ON_ERROR(AudioMoth_writeToFile(&wavHeader, sizeof(wavHeader)));
+    FLASH_LED_AND_RETURN_ON_ERROR(AudioMoth_writeToFile(&wavHeader, sizeof(wavHeader_t)));
 
     /* Close the file */