diff --git a/software/apps/audio_module/event_detector/Makefile b/software/apps/audio_module/event_detector/Makefile
new file mode 100644
index 00000000..79be72e1
--- /dev/null
+++ b/software/apps/audio_module/event_detector/Makefile
@@ -0,0 +1,24 @@
+# makefile for user application
+
+# the current directory
+APP_DIR := $(dir $(abspath $(lastword $(MAKEFILE_LIST))))
+
+# files needed for this code
+C_SRCS   := $(wildcard *.c) 
+C_SRCS   := $(wildcard **/log2fix.c) 
+#C_SRCS   += ./log2fix/log2fix.c
+#C_SRCS   += ./kiss_fft/kiss_fft.c
+#C_SRCS   += ./kiss_fft/tools/kiss_fftr.c
+#C_SRCS   += ./gcwa/c/ridgeTracker.c
+#C_SRCS   += ./gcwa/c/dynArray.c
+
+INCLUDE_PATHS += . ./kiss_fft ./kiss_fft/tools ./log2fix ./gcwa/c
+
+CFLAGS += -DFIXED_POINT=16 -std=c99
+CFLAGS += -Wno-type-limits -Wno-sign-compare
+
+TOCK_BOARD = audio_module
+
+# include makefile settings that are shared between applications
+include ../../AppMakefile.mk
+
diff --git a/software/apps/audio_module/event_detector/README.md b/software/apps/audio_module/event_detector/README.md
new file mode 100644
index 00000000..59887354
--- /dev/null
+++ b/software/apps/audio_module/event_detector/README.md
@@ -0,0 +1,25 @@
+# Universal acoustic event detection app
+The first step into any audio processing chain.
+
+Detect a large class of "acoustic events" (bird calls, gunshots, broken glasses, etc.) from noisy background.
+Further classifications are reserved for downstream processing.
+
+## Quick start
+1. Plug the Audio Module into the `Module 1` slot
+
+2.  **Important** Make sure the programming knob is turned to `MOD1`.
+
+3. Get all the prerequisites (See below)
+
+4. Flash the app
+
+    ```bash
+        cd signpost/software/apps/audio_module/event_detector
+        make flash
+    ```
+
+## Prerequisites
+* Fixed-point FFT: git clone https://github.com/longle2718/kiss_fft
+* Fixed-point log: git clone https://github.com/dmoulding/log2fix
+* Ridge tracker: git clone https://bitbucket.org/longle1/gcwa
+  * Fixed-point implementation in C is under gcwa/c/
diff --git a/software/apps/audio_module/event_detector/main.c b/software/apps/audio_module/event_detector/main.c
new file mode 100644
index 00000000..8570acf2
--- /dev/null
+++ b/software/apps/audio_module/event_detector/main.c
@@ -0,0 +1,161 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <adc.h>
+#include <console.h>
+#include <gpio.h>
+#include <led.h>
+#include <timer.h>
+#include <tock.h>
+
+#include "app_watchdog.h"
+#include "signpost_api.h"
+#include "simple_post.h"
+#include "_kiss_fft_guts.h"
+#include "kiss_fftr.h"
+#include "common.h"
+#include "ridgeTracker.h"
+
+static int freqAnalyze(kiss_fft_scalar *frame, kiss_fft_scalar *spec);
+static int printMat(char *filename, kiss_fft_scalar *in, size_t N);
+static int printMat2(char *filename, size_t *in, size_t N);
+
+int main (void) {
+    int err = SUCCESS;
+    printf("[Audio Module] Event Detector\n");
+
+    // initialize ADC
+    err = adc_initialize();
+    if (err < SUCCESS) {
+        printf("Initialize errored: %d\n", err);
+    }
+
+    static kiss_fft_scalar frame[BUF_LEN];
+    static kiss_fft_scalar spec[FRE_LEN];
+    static kiss_fft_scalar snrOut[FRE_LEN];
+    memset(frame, 0, BUF_LEN*sizeof(kiss_fft_scalar));
+    size_t frameIdx = 0;
+    size_t globTI = 0;
+    ridgeTracker_init();
+    while (true) {
+        // read data from ADC
+        for (size_t k = frameIdx; k < frameIdx+INC_LEN; k++){
+            err = adc_read_single_sample(3);
+            if (err < SUCCESS) {
+                printf("ADC read error: %d\n", err);
+            }
+            uint16_t sample = err & 0xFFFF;
+            frame[k] = (kiss_fft_scalar)sample;
+        }
+        frameIdx = (frameIdx+INC_LEN) % BUF_LEN;
+
+        // perform FFT
+        if (freqAnalyze(frame, spec)){
+            printf("freqAnalyze() failed!\n");
+            return 1;
+        }
+
+        // ridgetracker update
+        ridgeTracker_update(spec, snrOut);
+
+        // check for available event
+        if (ridgeTracker_isReady){
+            printf("Event detected!\n");
+            printf("ridgeTracker_out.used =  %zu\n",ridgeTracker_out.used);
+
+            if (printMat("SNR.mat",ridgeTracker_out.SNR,ridgeTracker_out.used)){
+                printf("printMat() failed!\n");
+                return 1;
+            }
+            if (printMat2("FI.mat",ridgeTracker_out.FI,ridgeTracker_out.used)){
+                printf("printMat2() failed!\n");
+                return 1;
+            }
+            size_t TIE = ridgeTracker_out.TI[ridgeTracker_out.used-1];
+            for (size_t k=0; k<ridgeTracker_out.used; k++){
+                ridgeTracker_out.TI[k] = globTI-(TIE-ridgeTracker_out.TI[k]);
+            }
+            if (printMat2("TI.mat",ridgeTracker_out.TI,ridgeTracker_out.used)){
+                printf("printMat2() failed!\n");
+                return 1;
+            }
+
+            ridgeTracker_reset();
+        }
+        globTI += 1;
+    }
+
+    ridgeTracker_destroy();
+
+    printf("Done!\n");
+    fflush(stdout);
+    return 0;
+}
+
+static int freqAnalyze(kiss_fft_scalar *frame, kiss_fft_scalar *spec){
+    // FFT data structure
+    kiss_fftr_cfg cfg;
+    kiss_fft_scalar in[BUF_LEN];
+    kiss_fft_cpx out[FRE_LEN + 1];
+    
+    static kiss_fft_scalar win[BUF_LEN] = {0x0000,0x0001,0x0004,0x000b,0x0013,0x001e,0x002c,0x003c,0x004f,0x0064,0x007b,0x0095,0x00b2,0x00d0,0x00f2,0x0115,0x013c,0x0164,0x018f,0x01bd,0x01ec,0x021f,0x0253,0x028a,0x02c4,0x0300,0x033e,0x037e,0x03c1,0x0406,0x044e,0x0497,0x04e3,0x0532,0x0583,0x05d5,0x062b,0x0682,0x06dc,0x0737,0x0796,0x07f6,0x0858,0x08bd,0x0923,0x098c,0x09f7,0x0a64,0x0ad3,0x0b44,0x0bb8,0x0c2d,0x0ca4,0x0d1d,0x0d98,0x0e15,0x0e94,0x0f15,0x0f98,0x101d,0x10a4,0x112c,0x11b6,0x1242,0x12d0,0x1360,0x13f1,0x1484,0x1519,0x15af,0x1647,0x16e0,0x177c,0x1818,0x18b7,0x1956,0x19f8,0x1a9a,0x1b3f,0x1be4,0x1c8b,0x1d34,0x1ddd,0x1e88,0x1f35,0x1fe2,0x2091,0x2141,0x21f3,0x22a5,0x2359,0x240d,0x24c3,0x257a,0x2632,0x26eb,0x27a5,0x285f,0x291b,0x29d8,0x2a95,0x2b53,0x2c12,0x2cd2,0x2d93,0x2e54,0x2f16,0x2fd9,0x309c,0x3160,0x3224,0x32e9,0x33ae,0x3474,0x353b,0x3601,0x36c9,0x3790,0x3858,0x3920,0x39e9,0x3ab1,0x3b7a,0x3c43,0x3d0c,0x3dd6,0x3e9f,0x3f68,0x4032,0x40fb,0x41c5,0x428e,0x4357,0x4420,0x44e9,0x45b2,0x467b,0x4743,0x480b,0x48d3,0x499a,0x4a61,0x4b28,0x4bee,0x4cb3,0x4d79,0x4e3d,0x4f01,0x4fc5,0x5088,0x514a,0x520c,0x52cd,0x538d,0x544c,0x550b,0x55c9,0x5686,0x5742,0x57fd,0x58b8,0x5971,0x5a29,0x5ae1,0x5b97,0x5c4c,0x5d00,0x5db3,0x5e65,0x5f16,0x5fc5,0x6074,0x6121,0x61cc,0x6277,0x6320,0x63c7,0x646e,0x6513,0x65b6,0x6658,0x66f9,0x6798,0x6835,0x68d1,0x696c,0x6a04,0x6a9c,0x6b31,0x6bc5,0x6c57,0x6ce7,0x6d76,0x6e03,0x6e8e,0x6f17,0x6f9f,0x7025,0x70a8,0x712a,0x71aa,0x7228,0x72a5,0x731f,0x7397,0x740d,0x7481,0x74f3,0x7564,0x75d2,0x763e,0x76a7,0x770f,0x7775,0x77d8,0x783a,0x7899,0x78f6,0x7950,0x79a9,0x79ff,0x7a53,0x7aa5,0x7af5,0x7b42,0x7b8d,0x7bd5,0x7c1c,0x7c60,0x7ca1,0x7ce1,0x7d1e,0x7d58,0x7d90,0x7dc6,0x7dfa,0x7e2b,0x7e59,0x7e86,0x7eaf,0x7ed7,0x7efc,0x7f1e,0x7f3e,0x7f5c,0x7f77,0x7f90,0x7fa6,0x7fba,0x7fcb,0x7fda,0x7fe6,0x7ff0,0x7ff8,0x7ffd,0x7fff,0x7fff,0x7ffd,0x7ff8,0x7ff0,0x7fe6,0x7fda,0x7fcb,0x7fba,0x7fa6,0x7f90,0x7f77,0x7f5c,0x7f3e,0x7f1e,0x7efc,0x7ed7,0x7eaf,0x7e86,0x7e59,0x7e2b,0x7dfa,0x7dc6,0x7d90,0x7d58,0x7d1e,0x7ce1,0x7ca1,0x7c60,0x7c1c,0x7bd5,0x7b8d,0x7b42,0x7af5,0x7aa5,0x7a53,0x79ff,0x79a9,0x7950,0x78f6,0x7899,0x783a,0x77d8,0x7775,0x770f,0x76a7,0x763e,0x75d2,0x7564,0x74f3,0x7481,0x740d,0x7397,0x731f,0x72a5,0x7228,0x71aa,0x712a,0x70a8,0x7025,0x6f9f,0x6f17,0x6e8e,0x6e03,0x6d76,0x6ce7,0x6c57,0x6bc5,0x6b31,0x6a9c,0x6a04,0x696c,0x68d1,0x6835,0x6798,0x66f9,0x6658,0x65b6,0x6513,0x646e,0x63c7,0x6320,0x6277,0x61cc,0x6121,0x6074,0x5fc5,0x5f16,0x5e65,0x5db3,0x5d00,0x5c4c,0x5b97,0x5ae1,0x5a29,0x5971,0x58b8,0x57fd,0x5742,0x5686,0x55c9,0x550b,0x544c,0x538d,0x52cd,0x520c,0x514a,0x5088,0x4fc5,0x4f01,0x4e3d,0x4d79,0x4cb3,0x4bee,0x4b28,0x4a61,0x499a,0x48d3,0x480b,0x4743,0x467b,0x45b2,0x44e9,0x4420,0x4357,0x428e,0x41c5,0x40fb,
+        0x4032,0x3f68,0x3e9f,0x3dd6,0x3d0c,0x3c43,0x3b7a,0x3ab1,0x39e9,0x3920,0x3858,0x3790,0x36c9,0x3601,0x353b,0x3474,0x33ae,0x32e9,0x3224,0x3160,0x309c,0x2fd9,0x2f16,0x2e54,0x2d93,0x2cd2,0x2c12,0x2b53,0x2a95,0x29d8,0x291b,0x285f,0x27a5,0x26eb,0x2632,0x257a,0x24c3,0x240d,0x2359,0x22a5,0x21f3,0x2141,0x2091,0x1fe2,0x1f35,0x1e88,0x1ddd,0x1d34,0x1c8b,0x1be4,0x1b3f,0x1a9a,0x19f8,0x1956,0x18b7,0x1818,0x177c,0x16e0,0x1647,0x15af,0x1519,0x1484,0x13f1,0x1360,0x12d0,0x1242,0x11b6,0x112c,0x10a4,0x101d,0x0f98,0x0f15,0x0e94,0x0e15,0x0d98,0x0d1d,0x0ca4,0x0c2d,0x0bb8,0x0b44,0x0ad3,0x0a64,0x09f7,0x098c,0x0923,0x08bd,0x0858,0x07f6,0x0796,0x0737,0x06dc,0x0682,0x062b,0x05d5,0x0583,0x0532,0x04e3,0x0497,0x044e,0x0406,0x03c1,0x037e,0x033e,0x0300,0x02c4,0x028a,0x0253,0x021f,0x01ec,0x01bd,0x018f,0x0164,0x013c,0x0115,0x00f2,0x00d0,0x00b2,0x0095,0x007b,0x0064,0x004f,0x003c,0x002c,0x001e,0x0013,0x000b,0x0004,0x0001,0x0000};
+    // windowing and prescaling 
+    for (size_t i = 0; i < BUF_LEN; i++){
+        in[i] = S_MUL(frame[i],win[i]) << 4;
+    }
+
+    if ((cfg = kiss_fftr_alloc(BUF_LEN, 0/*is_inverse_fft*/, NULL, NULL)) == NULL){
+        printf("Not enough memory?\n");
+        return 1;
+    }else{
+        kiss_fftr(cfg, in, out);
+        free(cfg);
+    }
+
+    for (size_t k = 0; k < FRE_LEN; k++){
+        spec[k] = MAG(out[k].r,out[k].i);
+    }
+
+    return 0;
+}
+
+static int printMat(char *filename, kiss_fft_scalar *in, size_t N){
+    FILE *fp;
+
+    if (! (fp = fopen(filename, "a"))){
+        printf("Unable to open %s\n",filename);
+        return 1;
+    }
+
+    for (size_t i = 0; i < N-1; i++){
+        //fprintf(fp, "%d,",in[i]);
+        fprintf(fp, "%f,",(double)in[i]/(double)SAMP_MAX);
+    }
+    //fprintf(fp, "%d\n",in[N-1]);
+    fprintf(fp, "%f\n",(double)in[N-1]/(double)SAMP_MAX);
+    
+    fclose(fp);
+    return 0;
+}
+
+static int printMat2(char *filename, size_t *in, size_t N){
+    FILE *fp;
+
+    if (! (fp = fopen(filename, "a"))){
+        printf("Unable to open %s\n",filename);
+        return 1;
+    }
+
+    for (size_t i = 0; i < N-1; i++){
+        fprintf(fp, "%zu,",in[i]);
+    }
+    fprintf(fp, "%zu\n",in[N-1]);
+    
+    fclose(fp);
+    return 0;
+}