diff --git a/lis3dh.c b/lis3dh.c
index 45b2c4e..dbcfcd5 100644
--- a/lis3dh.c
+++ b/lis3dh.c
@@ -47,16 +47,13 @@ int lis3dh_init(lis3dh_t *lis3dh) {
         }
     }
 
+    /* check WHO_AM_I to equal to 0x33 */
     err |= lis3dh->dev.read(REG_WHO_AM_I, &result, 1);
     if (result != 0x33) {
        return 1;
     }
 
-    /* zero struct */
-    lis3dh->acc.x = 0.0;
-    lis3dh->acc.y = 0.0;
-    lis3dh->acc.z = 0.0;
-
+    /* zero device struct */
     lis3dh->cfg.rate = 0;
     lis3dh->cfg.range = 0;
     lis3dh->cfg.mode = 0;
@@ -65,29 +62,13 @@ int lis3dh_init(lis3dh_t *lis3dh) {
     lis3dh->cfg.fifo.trig = 0;
     lis3dh->cfg.fifo.fth = 31; /* default watermark level. */
 
+    memset(&lis3dh->acc, 0, sizeof lis3dh->acc);
+    memset(&lis3dh->cfg.int1, 0, sizeof lis3dh->cfg.int1);
+    memset(&lis3dh->cfg.int2, 0, sizeof lis3dh->cfg.int2);
+    memset(&lis3dh->cfg.filter, 0, sizeof lis3dh->cfg.filter);
+
     lis3dh->cfg.filter.mode = 0xFF; /* in use if neq 0xFF */
-    lis3dh->cfg.filter.cutoff = 0;
     lis3dh->cfg.filter.fds = 1; /* bypass OFF by default */
-    lis3dh->cfg.filter.click = 0;
-    lis3dh->cfg.filter.ia1 = 0;
-    lis3dh->cfg.filter.ia2 = 0;
-
-    lis3dh->cfg.int1.click = 0;
-    lis3dh->cfg.int1.ia1 = 0;
-    lis3dh->cfg.int1.ia2 = 0;
-    lis3dh->cfg.int1.drdy_zyxda = 0;
-    lis3dh->cfg.int1.drdy_321 = 0;
-    lis3dh->cfg.int1.wtm = 0;
-    lis3dh->cfg.int1.overrun = 0;
-    lis3dh->cfg.int1.latch = 0;
-
-    lis3dh->cfg.int2.click = 0;
-    lis3dh->cfg.int2.ia1 = 0;
-    lis3dh->cfg.int2.ia2 = 0;
-    lis3dh->cfg.int2.boot = 0;
-    lis3dh->cfg.int2.act = 0;
-    lis3dh->cfg.int2.polarity = 0;
-    lis3dh->cfg.int2.latch = 0;
 
     err |= lis3dh_reset(lis3dh);
 
diff --git a/lis3dh.h b/lis3dh.h
index e48de43..6d9bf2a 100644
--- a/lis3dh.h
+++ b/lis3dh.h
@@ -55,6 +55,7 @@
 #define LIS3DH_FILTER_CUTOFF_1 0x03 /* lowest freq */
 
 
+/* user provided functions, init and deinit can be set to NULL and won't be used */
 struct lis3dh_device {
 	int (*init)(void);
 	int (*read)(uint8_t reg, uint8_t *dst, uint32_t size);
@@ -63,6 +64,7 @@ struct lis3dh_device {
 	int (*deinit)(void);
 };
 
+/* config for INT2 trigger output */
 struct lis3dh_int2_config {
     uint8_t click; /* CLICK interrupt */
     uint8_t ia1; /* IA1 interrupt */
@@ -73,6 +75,7 @@ struct lis3dh_int2_config {
     uint8_t latch;  /* latch interrupt until cleared */
 };
 
+/* config for INT1 trigger output */
 struct lis3dh_int1_config {
     uint8_t click; /* CLICK interrupt */
     uint8_t ia1; /* IA1 interrupt */
@@ -84,6 +87,7 @@ struct lis3dh_int1_config {
     uint8_t latch; /* latch interrupt until cleared */
 };
 
+/* config for high-pass filter */
 struct lis3dh_filter_config {
     uint8_t mode; /* filter mode, reset behaviour */
     uint8_t cutoff; /* high-pass filter cutoff freq (~ ODR) */
@@ -93,6 +97,7 @@ struct lis3dh_filter_config {
     uint8_t ia1; /* enable filter for AOI func on INT 1 */
 };
 
+/* config for FIFO */
 struct lis3dh_fifo_config {
     uint8_t fth; /* user-specified watermark level 0-32 */
     uint8_t trig; /* pin to trigger when watermark/overrun occurs */
@@ -109,6 +114,7 @@ struct lis3dh_config {
     struct lis3dh_int2_config int2;
 };
 
+/* data read not from FIFO is put here */
 struct lis3dh_acceleration {
     float x;
     float y;
@@ -142,6 +148,4 @@ int lis3dh_clear_int1(lis3dh_t *lis3dh);
 int lis3dh_clear_int2(lis3dh_t *lis3dh);
 int lis3dh_reference(lis3dh_t *lis3dh);
 
-
-
 #endif
\ No newline at end of file