more src reg interaction

lis3dh.c

@@ -25,6 +25,7 @@ int lis3dh_init(lis3dh_t *lis3dh) {
     memset(&lis3dh->acc, 0, sizeof lis3dh->acc);
     memset(&lis3dh->cfg, 0, sizeof lis3dh->cfg);
     memset(&lis3dh->adc, 0, sizeof lis3dh->adc);
+    memset(&lis3dh->src, 0, sizeof lis3dh->src);
 
     lis3dh->cfg.fifo.mode = 0xFF; /* in use if neq 0xFF */
     lis3dh->cfg.fifo.fth = 31; /* default watermark level. */
@@ -161,6 +162,7 @@ int lis3dh_configure(lis3dh_t *lis3dh) {
     }
 
     /* always set block update (BDU) */
+    /* guarantees all bytes for one [x y z] set were sampled at the same time */
     ctrl_reg4 |= 0x80;
 
     /* set high resolution */
@@ -322,16 +324,19 @@ int lis3dh_deinit(lis3dh_t *lis3dh) {
     return 0;
 }
 
-/* read INT1_SRC to clear latched INT1 irq */
+/* read INT1_SRC to clear interrupt active flag and get relevant data */
-int lis3dh_clear_int1(lis3dh_t *lis3dh) {
+int lis3dh_read_int1(lis3dh_t *lis3dh) {
-    uint8_t res;
+    return lis3dh->dev.read(REG_INT1_SRC, &lis3dh->src.int1, 1);
-    return lis3dh->dev.read(REG_INT1_SRC, &res, 1);
 }
 
-/* read INT2_SRC to clear latched INT2 irq */
+/* read INT2_SRC to clear interrupt active flag and get relevant data */
-int lis3dh_clear_int2(lis3dh_t *lis3dh) {
+int lis3dh_read_int2(lis3dh_t *lis3dh) {
-    uint8_t res;
+    return lis3dh->dev.read(REG_INT2_SRC, &lis3dh->src.int2, 1);
-    return lis3dh->dev.read(REG_INT2_SRC, &res, 1);
+}
+
+/* read CLICK_SRC to clear interrupt active flag and get relevant data */
+int lis3dh_read_click(lis3dh_t *lis3dh) {
+    return lis3dh->dev.read(REG_CLICK_SRC, &lis3dh->src.click, 1);
 }
 
 /* read REFERENCE reg to reset HP filter in REFERENCE mode
@@ -375,7 +380,7 @@ int lis3dh_reset(lis3dh_t *lis3dh) {
 }
 
 /* read all 3 ADCs and convert readings depending on power mode
-   st 1 LSb is equal to 1 millivolt */
+   st 1 float count is equal to 1 millivolt */
 int lis3dh_read_adc(lis3dh_t *lis3dh) {
     uint8_t data[6];
     int err = 0;

lis3dh.h

@@ -3,6 +3,22 @@
 
 #include <stdint.h>
 
+/* macros for checking INT_SRC registers upon interrupt */
+#define LIS3DH_INT_SRC_X_LOW(c)  ((c & 1) == 1)
+#define LIS3DH_INT_SRC_X_HIGH(c) (((c >> 1) & 1) == 1)
+#define LIS3DH_INT_SRC_Y_LOW(c)  (((c >> 2) & 1) == 1)
+#define LIS3DH_INT_SRC_Y_HIGH(c) (((c >> 3) & 1) == 1)
+#define LIS3DH_INT_SRC_Z_LOW(c)  (((c >> 4) & 1) == 1)
+#define LIS3DH_INT_SRC_Z_HIGH(c) (((c >> 5) & 1) == 1)
+
+/* macros for checking CLICK_SRC register upon interrupt */
+#define LIS3DH_CLICK_SRC_X(c)    ((c & 1) == 1)        /* X high event */
+#define LIS3DH_CLICK_SRC_Y(c)    (((c >> 1) & 1) == 1) /* Y high event */
+#define LIS3DH_CLICK_SRC_Z(c)    (((c >> 2) & 1) == 1) /* Z high event */
+#define LIS3DH_CLICK_SIGN(c)     (((c >> 3) & 1) == 1) /* Click sign, 1 = positive */
+#define LIS3DH_CLICK_SCLICK(c)   (((c >> 4) & 1) == 1) /* Single-click det. enabled */
+#define LIS3DH_CLICK_DCLICK(c)   (((c >> 5) & 1) == 1) /* Double-click det. enabled */
+
 /* rates */
 /* all power modes */
 #define LIS3DH_ODR_POWEROFF 0x00
@@ -41,11 +57,29 @@
 #define LIS3DH_FIFO_TRIG_INT2 0x01
 
 /* filter modes */
-/* this one is reset by reading REFERENCE (0x26) */
+/* Normal mode
-#define LIS3DH_FILTER_MODE_NORMAL 0x00
+ * but reset by reading REFERENCE, instantly removes the DC component 
-#define LIS3DH_FILTER_MODE_REFERENCE 0x01
+ */
-#define LIS3DH_FILTER_MODE_NORMAL2 0x02 /* same as 00? */
+#define LIS3DH_FILTER_MODE_NORMAL_REF 0x00
-#define LIS3DH_FILTER_MODE_AUTORESET 0x03
+/* Reference mode
+ * Output [x y z] data is calculated as the difference between the 
+ * measured acceleration and the value stored in REFERENCE.
+ * signed 7-bit int, 1 LSb value depends on FS.
+ * FS_2G: ~ 16mg per 1 LSb 
+ * FS_4G: ~ 31mg per 1 LSb 
+ * FS_8G: ~ 63mg per 1 LSb
+ * FS_16G: ~127mg per 1 LSb
+ * */
+#define LIS3DH_FILTER_MODE_REFERENCE  0x01
+/* Normal mode
+ * Probably the same as LIS3DH_FILTER_MODE_NORMAL_REF
+ */
+#define LIS3DH_FILTER_MODE_NORMAL     0x02 
+/* Autoreset mode
+ * The filter is automatically reset upon configured interrupt event.
+ * It can be reset at any time by reading REFERENCE.
+ */
+#define LIS3DH_FILTER_MODE_AUTORESET  0x03
 
 /* filter cutoff */
 /* unfortunately, there is only a table for low-power mode,
@@ -207,11 +241,19 @@ struct lis3dh_accel {
     float z;
 };
 
+/* stores interrupt source registers read from the device */
+struct lis3dh_interrupt_src {
+    uint8_t int1;
+    uint8_t int2;
+    uint8_t click;
+};
+
 struct lis3dh {
-    struct lis3dh_device dev;
+    struct lis3dh_device        dev; /* fn ptrs to interface w/ device */
-    struct lis3dh_config cfg;
+    struct lis3dh_config        cfg; /* config variables to write to device */
-    struct lis3dh_accel  acc;
+    struct lis3dh_accel         acc; /* accel data read from device (not FIFO) */
-    struct lis3dh_adc    adc;
+    struct lis3dh_adc           adc; /* adc and optionally temp read from device */
+    struct lis3dh_interrupt_src src; /* INT_SRC registers read from device */
 };
 
 typedef struct lis3dh lis3dh_t;
@@ -231,8 +273,9 @@ int lis3dh_poll(lis3dh_t *lis3dh);
 int lis3dh_read(lis3dh_t *lis3dh);
 int lis3dh_poll_fifo(lis3dh_t *lis3dh);
 int lis3dh_read_fifo(lis3dh_t *lis3dh, struct lis3dh_fifo_data *fifo);
-int lis3dh_clear_int1(lis3dh_t *lis3dh);
+int lis3dh_read_int1(lis3dh_t *lis3dh);
-int lis3dh_clear_int2(lis3dh_t *lis3dh);
+int lis3dh_read_int2(lis3dh_t *lis3dh);
+int lis3dh_read_click(lis3dh_t *lis3dh);
 int lis3dh_reference(lis3dh_t *lis3dh);
 int lis3dh_reset(lis3dh_t *lis3dh);
 int lis3dh_read_adc(lis3dh_t *lis3dh);

main.c

@@ -58,7 +58,7 @@ int main() {
     lis.cfg.fifo.trig = LIS3DH_FIFO_TRIG_INT2;
     lis.cfg.pin1.wtm = 1;
     lis.cfg.pin1.latch = 1;
-    lis.cfg.filter.mode = LIS3DH_FILTER_MODE_AUTORESET;
+    lis.cfg.filter.mode = LIS3DH_FILTER_MODE_NORMAL;
     lis.cfg.filter.cutoff = LIS3DH_FILTER_CUTOFF_8;
 
     lis.cfg.en_adc = 1;
@@ -76,7 +76,7 @@ int main() {
         }
 
         /* clear latched interrupt on INT1 */
-        if (lis3dh_clear_int1(&lis)) {
+        if (lis3dh_read_int1(&lis)) {
             quit("clear_int1()", &lis);
         }