single-click detection & fixed examples

README.md

@@ -3,15 +3,19 @@
 A C89 driver for the 3-axis accelerometer LIS3DH. Supports both i2c and SPI. 
 
 > ### Features
-> - FIFO of varying watermark level, up to 32
+> - FIFO 
-> - HP filter (4 c/o freq)
+> - HP filter
 > - 2G, 4G, 8G and 16G
 > - All power modes
-> - Interrupt generation (partial)
+> - Interrupt generation
 > - Free-fall detection (soon)
-> - Single and double click detection (soon)
+> - Single-click detection
+> - Double-click detection (soon)
 > - 4D/6D orientation detection (soon)
 
+## Examples
+See the examples/ dir for complete code examples
+
 ## Implementation
 This driver requires the user to provide pointers to the following abstractely named functions:
 

example/README.md

@@ -1,12 +1,16 @@
 # lis3dh/example
 
-### simple/
+### simple.c
 Basic examples of how to use this device
 
-### fifo/
+### fifo.c
 Instead of polling for every single [x y z] set, a FIFO with programmable capacity ("watermark") can be used like such: All FIFO readings use 10-bit resolution regardless of the mode set in `lis.cfg.mode`. The watermark level can also be adjusted to a value [0-31] inclusive by modifying the `lis.cfg.fifo.fth` property before calling configure().
 
 The LIS3DH can optionally apply a HP filter on the sample data. It can be used to greatly reduce the "DC acceleration" present.
 
-### interrupts/
+### interrupts.c
 The LIS3DH supports two different interrupt "output pins," `INT1` and `INT2`. The appropriate flag must be set in either `cfg.int1` or `cfg.int2` (only one of such flags can be set at a time!) and the interrupt source must be configured to trigger into `INT1` or `INT2`. Below is example code that listens and receives an interrupt when the FIFO watermark is reached i.e. it is full.
+
+### single-click.c
+
+Set up single-click detection using HP filter

example/fifo/fifo2.c

@@ -1,52 +0,0 @@
-#define _GNU_SOURCE
-#include <unistd.h>
-#include <stdio.h>
-#include "lis3dh.h"
-#include "i2c.h"
-
-int main() {
-
-    lis3dh_t lis;
-    struct lis3dh_fifo_data data;
-    int i;
-
-    lis.dev.init = i2c_init;
-    lis.dev.read = i2c_read;
-    lis.dev.write = i2c_write;
-    lis.dev.sleep = usleep;
-    lis.dev.deinit = i2c_deinit;
-
-    if (lis3dh_init(&lis)) {
-        /* error handling */
-    }
-
-    lis.cfg.mode = LIS3DH_MODE_HR;
-    lis.cfg.range = LIS3DH_FS_4G;
-    lis.cfg.rate = LIS3DH_ODR_100_HZ;
-    lis.cfg.fifo.mode = LIS3DH_FIFO_MODE_NORMAL;
-    lis.cfg.filter.mode = LIS3DH_FILTER_MODE_AUTORESET;
-    lis.cfg.filter.cutoff = LIS3DH_FILTER_CUTOFF_8;
-
-    if (lis3dh_configure(&lis)) {
-        /* error handling */
-    }
-
-    if (lis3dh_poll_fifo(&lis)) {
-        /* error handling */
-    }
-
-    if (lis3dh_read_fifo(&lis, &data)) {
-        /* error handling */
-    }
-
-    /* read out fifo buffer data */
-    for(i=0; i<data.size; i++) {
-        printf("x: %f, y: %f, z: %f\n", data.x[i], data.y[i], data.z[i]);
-    }
-
-    if (lis3dh_deinit(&lis)) {
-        /* error handling */
-    }
-
-    return 0;
-}

example/interrupts.c

@@ -26,6 +26,11 @@ int main() {
         /* error handling */
     }
 
+    /* device sometimes corrupts itself, so reset .. */
+    if (lis3dh_reset(&lis)) {
+        /* error handling */
+    }
+
     /* register interrupt */
     if (int_register(GPIO_INTERRUPT_PIN)) {
         /* error handling */
@@ -36,7 +41,10 @@ int main() {
     lis.cfg.rate = LIS3DH_ODR_100_HZ;
     lis.cfg.fifo.mode = LIS3DH_FIFO_MODE_STREAM;
     lis.cfg.fifo.trig = LIS3DH_FIFO_TRIG_INT1; /* trigger into INT1 */
-    lis.cfg.int1.wtm = 1; /* trigger upon watermark level reached */
+    lis.cfg.pin1.wtm = 1; /* trigger upon watermark level reached */
+    /* set up HP filter to remove DC component */
+    lis.cfg.filter.mode = LIS3DH_FILTER_MODE_NORMAL;
+    lis.cfg.filter.cutoff = LIS3DH_FILTER_CUTOFF_4;
     
     if (lis3dh_configure(&lis)) {
        /* error handling */
@@ -52,7 +60,7 @@ int main() {
     }
 
     for(k=0; k<fifo.size; k++) {
-        printf("%04.04f %04.04f %04.04f %04.04f\n", fifo.x[k], fifo.y[k], fifo.z[k]);
+        printf("x: %04.04f, y: %04.04f z: %04.04f\n", fifo.x[k], fifo.y[k], fifo.z[k]);
     }
     
     /* unregister interrupt */

example/simple.c

@@ -18,6 +18,11 @@ int main() {
         /* error handling */
     }
 
+    /* device sometimes corrupts itself, so reset .. */
+    if (lis3dh_reset(&lis)) {
+        /* error handling */
+    }
+
     lis.cfg.mode = LIS3DH_MODE_HR;
     lis.cfg.range = LIS3DH_FS_4G;
     lis.cfg.rate = LIS3DH_ODR_100_HZ;

example/simple/simple2.c

@@ -1,48 +0,0 @@
-#define _GNU_SOURCE
-#include <unistd.h>
-#include <stdio.h>
-#include "lis3dh.h"
-#include "i2c.h"
-
-int main() {
-
-    lis3dh_t lis;
-    int i;
-
-    lis.dev.init = i2c_init;
-    lis.dev.read = i2c_read;
-    lis.dev.write = i2c_write;
-    lis.dev.sleep = usleep;
-    lis.dev.deinit = i2c_deinit;
-
-    if (lis3dh_init(&lis)) {
-        /* error handling */
-    }
-
-    lis.cfg.mode = LIS3DH_MODE_HR;
-    lis.cfg.range = LIS3DH_FS_4G;
-    lis.cfg.rate = LIS3DH_ODR_100_HZ;
-
-    if (lis3dh_configure(&lis)) {
-        /* error handling */
-    }
-
-    for(i=0; i<10; i++) {
-
-        if (lis3dh_poll(&lis)) {
-            /* error handling */
-        }
-
-        if (lis3dh_read(&lis)) {
-            /* error handling */
-        }
-
-        printf("x: %f, y: %f, z: %f\n", lis.acc.x, lis.acc.y, lis.acc.z);
-    }
-
-    if (lis3dh_deinit(&lis)) {
-        /* error handling */
-    }
-
-    return 0;
-}

example/single-click.c

@@ -0,0 +1,107 @@
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <math.h>
+#include "lis3dh.h"
+#include "interrupt.h"
+#include "i2c.h"
+
+#define GPIO_INTERRUPT_PIN_INT1 12
+
+int main() {
+
+    lis3dh_t lis;
+
+    /* set fn ptrs to rw on bus (i2c or SPI) */
+    lis.dev.init = i2c_init;
+    lis.dev.read = i2c_read;
+    lis.dev.write = i2c_write;
+    lis.dev.sleep = usleep;
+    lis.dev.deinit = i2c_deinit;
+
+    /* initialise LIS3DH struct */
+    if (lis3dh_init(&lis)) {
+        /* error handling */
+    }
+
+    /* reset device because it sometimes corrupts itself */
+    if (lis3dh_reset(&lis)) {
+        /* error handling */
+    }
+
+    /* register interrupt */
+    if (int_register(GPIO_INTERRUPT_PIN_INT1)) {
+        /* error handling */
+    }
+
+    /* set up config */
+    lis.cfg.mode = LIS3DH_MODE_HR;
+    lis.cfg.range = LIS3DH_FS_2G;
+    lis.cfg.rate = LIS3DH_ODR_400_HZ; /* minimum recommended ODR */
+    lis.cfg.filter.mode = LIS3DH_FILTER_MODE_NORMAL;
+    lis.cfg.filter.cutoff = LIS3DH_FILTER_CUTOFF_8;
+    lis.cfg.filter.click = 1; /* enable filtering for CLICK function */
+    lis.cfg.click.xs = 1; /* enable X axis single click */
+    lis.cfg.click.ys = 1; /* enable Y axis single click */
+    lis.cfg.click.zs = 1; /* enable Z axis single click */
+    lis.cfg.pin1.click = 1; /* enable click int src through pin1 */
+    lis.cfg.pin1.latch = 1; /* latch this request I think */
+
+    /* 1 LSb = 16 mg @ FS_2G 
+     * so a 0.072g 'shock' is 72/16 = 4.5
+     * However, the device can have up to +- 40mg read error
+     * 0.112g => 112/16 = 15
+     */
+    lis.cfg.click_ths = 7; /* pretty sensitive */
+
+    /* the 'shock' must be gone after 10 ms let's say .. */
+        /* Duration time is measured in N/ODR where:
+     * --- N = The content of the intX_dur integer
+     * --- ODR = the data rate, eg 100, 400...
+     * [ODR] [1 LSb in milliseconds]
+     *   400    2.5
+     * 
+     * At 400 ODR, 10ms/2.5ms = 4
+     */
+    lis.cfg.time_limit = 4;
+    
+    /* write device config */
+    if (lis3dh_configure(&lis)) {
+        /* error handling */
+    }
+
+    for(;;) {
+
+        /* poll interrupt on INT1 pin */
+        if (int_poll(GPIO_INTERRUPT_PIN_INT1)) {
+            /* error handling */
+        }
+
+        /* read CLICK_SRC when interrupt has fired */
+        if (lis3dh_read_click(&lis)) {
+            /* error handling */
+        }
+
+        /* print data gathered from CLICK_SRC */
+        printf("Click: X=%d, Y=%d, Z=%d, Sign=%d, S_en=%d, D_en=%d\n",
+            LIS3DH_CLICK_SRC_X(lis.src.click),
+            LIS3DH_CLICK_SRC_Y(lis.src.click),
+            LIS3DH_CLICK_SRC_Z(lis.src.click),
+            LIS3DH_CLICK_SIGN(lis.src.click),
+            LIS3DH_CLICK_SCLICK(lis.src.click),
+            LIS3DH_CLICK_DCLICK(lis.src.click));
+    }
+    
+    /* unregister interrupt */
+    if (int_unregister(GPIO_INTERRUPT_PIN_INT1)) {
+        /* error handling */
+    }
+
+    /* deinitalise struct */
+    if (lis3dh_deinit(&lis)) {
+        /* error handling */
+    }
+
+    return 0;
+}