cleanup unused or unnecessary code

lis3dh.c

@@ -1,5 +1,6 @@
 #include <stddef.h>
 #include <string.h>
+#include <stdio.h>
 #include "lis3dh.h"
 #include "registers.h"
 
@@ -24,6 +25,7 @@ int lis3dh_init(lis3dh_t *lis3dh) {
     /* zero device struct */
     memset(&lis3dh->acc, 0, sizeof lis3dh->acc);
     memset(&lis3dh->cfg, 0, sizeof lis3dh->cfg);
+    memset(&lis3dh->adc, 0, sizeof lis3dh->adc);
 
     lis3dh->cfg.fifo.mode = 0xFF; /* in use if neq 0xFF */
     lis3dh->cfg.fifo.fth = 31; /* default watermark level. */
@@ -41,9 +43,7 @@ int lis3dh_configure(lis3dh_t *lis3dh) {
     uint8_t fifo_ctrl_reg, int1_cfg, int2_cfg;
     uint8_t int1_ths, int2_ths, int1_dur, int2_dur;
     uint8_t click_cfg, click_ths;
-    uint8_t time_limit, time_latency, time_window;
+    uint8_t time_limit, act_ths;
-    uint8_t act_ths, act_dur;
-    uint8_t ref; /* dummy */
     int err = 0;
 
     /* the 0x07 enables Z, Y and X axis in that order */
@@ -63,10 +63,7 @@ int lis3dh_configure(lis3dh_t *lis3dh) {
     click_cfg = 0;
     click_ths = 0;
     time_limit = 0;
-    time_latency = 0;
-    time_window = 0;
     act_ths = 0;
-    act_dur = 0;
     ctrl_reg0 = 0;
     temp_cfg_reg = 0;
 
@@ -77,12 +74,7 @@ int lis3dh_configure(lis3dh_t *lis3dh) {
     /* set time limit */
     time_limit |= (lis3dh->cfg.time_limit & 0x7F);
 
-    /* set time latency and window */
-    time_latency = lis3dh->cfg.time_latency;
-    time_window = lis3dh->cfg.time_window;
-
     act_ths |= (lis3dh->cfg.act_ths & 0x7F); 
-    act_dur = lis3dh->cfg.act_dur;
 
     /* set click config register */
     click_cfg |= (lis3dh->cfg.click.xs & 1);
@@ -197,10 +189,10 @@ int lis3dh_configure(lis3dh_t *lis3dh) {
     err |= lis3dh->dev.write(REG_CLICK_CFG, click_cfg);
     err |= lis3dh->dev.write(REG_CLICK_THS, click_ths);
     err |= lis3dh->dev.write(REG_TIME_LIMIT, time_limit);
-    err |= lis3dh->dev.write(REG_TIME_LATENCY, time_latency);
+    err |= lis3dh->dev.write(REG_TIME_LATENCY, lis3dh->cfg.time_latency);
-    err |= lis3dh->dev.write(REG_TIME_WINDOW, time_window);
+    err |= lis3dh->dev.write(REG_TIME_WINDOW, lis3dh->cfg.time_window);
     err |= lis3dh->dev.write(REG_ACT_THS, act_ths);
-    err |= lis3dh->dev.write(REG_ACT_DUR, act_dur);
+    err |= lis3dh->dev.write(REG_ACT_DUR, lis3dh->cfg.act_dur);
     err |= lis3dh->dev.write(REG_TEMP_CFG_REG, temp_cfg_reg);
 
     err |= lis3dh->dev.write(REG_CTRL_REG0, ctrl_reg0);
@@ -211,10 +203,6 @@ int lis3dh_configure(lis3dh_t *lis3dh) {
     err |= lis3dh->dev.write(REG_CTRL_REG5, ctrl_reg5);
     err |= lis3dh->dev.write(REG_CTRL_REG6, ctrl_reg6);
 
-
-    /* read REFERENCE to clear internal filter struct */
-    err |= lis3dh->dev.read(REG_REFERENCE, &ref, 1);
-
     /* sleep for a period TBD ~ ODR */
     lis3dh->dev.sleep(50000); /* 50 ms */
     return err;
@@ -305,8 +293,8 @@ int lis3dh_read_fifo(lis3dh_t *lis3dh, struct lis3dh_fifo_data *fifo) {
     scale = 6;
     sens = acc_sensitivity(lis3dh->cfg.mode, lis3dh->cfg.range);
 
-    /* fifo buffer is max 32 */
+    /* fifo buffer is max 31 */
-    fifo->size = lis3dh->cfg.fifo.fth > 32 ? 32 : lis3dh->cfg.fifo.fth;
+    fifo->size = lis3dh->cfg.fifo.fth > 31 ? 31 : lis3dh->cfg.fifo.fth;
 
     /* must set MSbit of the address to multi-read and 
        have the device auto-increment the address.
@@ -353,6 +341,7 @@ int lis3dh_reference(lis3dh_t *lis3dh) {
     uint8_t res;
     return lis3dh->dev.read(REG_REFERENCE, &res, 1);
 }
+
 /* reset user regs and reload trim params */
 int lis3dh_reset(lis3dh_t *lis3dh) {
     int err = 0;
@@ -385,3 +374,43 @@ int lis3dh_reset(lis3dh_t *lis3dh) {
     
     return err;
 }
+
+/* read all 3 ADCs and convert readings depending on power mode
+   st 1 LSb is equal to 1 millivolt */
+int lis3dh_read_adc(lis3dh_t *lis3dh) {
+    uint8_t data[6];
+    int err = 0;
+    uint8_t shift;
+    float divisor;
+    /* read adc{1,2,3} LSB and MSB */
+    err |= lis3dh->dev.read(REG_OUT_ADC1_L | 0x80, data, 6);
+
+    if (lis3dh->cfg.mode == LIS3DH_MODE_LP) {
+        shift = 8;
+        divisor = 256.0;
+    } else {
+        shift = 6;
+        divisor = 1024.0;
+    }
+
+    lis3dh->adc.adc1 = 1200.0 + (400.0 * (float)(((int16_t)(data[1] | (data[0] << 8))) >> shift) / divisor); 
+    lis3dh->adc.adc2 = 1200.0 + (400.0 * (float)(((int16_t)(data[3] | (data[2] << 8))) >> shift) / divisor); 
+    lis3dh->adc.adc3 = 1200.0 + (400.0 * (float)(((int16_t)(data[5] | (data[4] << 8))) >> shift) / divisor); 
+
+    return err;
+}
+
+/* the temperature sensor only reports the difference between its current temp,
+   and the factory calibrated temperature, 25 celsius.
+   in increments of plus or negative 1 unit celsius.
+   the reported temperature is stored inplace of adc3 
+   temp sensing is always in 8-bit mode 
+   operating range: -40 to 85 celsius */
+int lis3dh_read_temp(lis3dh_t *lis3dh) {
+    uint8_t data;
+    int err = 0;
+
+    err |= lis3dh->dev.read(REG_OUT_ADC3_H, &data, 1);
+    lis3dh->adc.adc3 = (float)((int8_t)data) + 25.0;
+    return err;
+}

lis3dh.h

@@ -173,8 +173,24 @@ struct lis3dh_config {
     uint8_t en_temp; /* enable temp sensor on ADC 3 */
 };
 
-/* data read not from FIFO is put here */
+/* reads from internal ADCs. 
-struct lis3dh_acceleration {
+ * Input range: 800 mV to 1600 mV 
+ * Resolution:
+ *              8-bit in LP mode
+ *             10-bit in normal and in HR mode.
+ * Sampling frequency:
+ *              same as ODR
+ * Output:
+ *            actual value in mV
+ */
+struct lis3dh_adc {
+    float adc1;
+    float adc2;
+    float adc3;
+};
+
+/* accel data not read from FIFO is put here */
+struct lis3dh_accel {
     float x;
     float y;
     float z;
@@ -183,7 +199,8 @@ struct lis3dh_acceleration {
 struct lis3dh {
     struct lis3dh_device dev;
     struct lis3dh_config cfg;
-    struct lis3dh_acceleration acc;
+    struct lis3dh_accel  acc;
+    struct lis3dh_adc    adc;
 };
 
 typedef struct lis3dh lis3dh_t;
@@ -207,5 +224,7 @@ int lis3dh_clear_int1(lis3dh_t *lis3dh);
 int lis3dh_clear_int2(lis3dh_t *lis3dh);
 int lis3dh_reference(lis3dh_t *lis3dh);
 int lis3dh_reset(lis3dh_t *lis3dh);
+int lis3dh_read_adc(lis3dh_t *lis3dh);
+int lis3dh_read_temp(lis3dh_t *lis3dh);
 
 #endif

main.c

@@ -35,7 +35,6 @@ int main() {
     lis.dev.sleep = usleep;
     lis.dev.deinit = i2c_deinit;
 
-
     /* initialise LIS3DH struct */
     if (lis3dh_init(&lis)) {
         quit("init()", &lis);
@@ -62,6 +61,8 @@ int main() {
     lis.cfg.filter.mode = LIS3DH_FILTER_MODE_AUTORESET;
     lis.cfg.filter.cutoff = LIS3DH_FILTER_CUTOFF_8;
 
+    lis.cfg.en_adc = 1;
+    lis.cfg.en_temp = 1;
     
     /* write device config */
     if (lis3dh_configure(&lis)) {
@@ -74,6 +75,7 @@ int main() {
             quit("int_poll()", &lis);
         }
 
+        /* clear latched interrupt on INT1 */
         if (lis3dh_clear_int1(&lis)) {
             quit("clear_int1()", &lis);
         }
@@ -83,10 +85,21 @@ int main() {
             quit("read_fifo()", &lis);
         }
 
+        /* read ADCs */
+        if (lis3dh_read_adc(&lis)) {
+            quit("read_adc()", &lis);
+        }
+
+        /* read temp from ADC3 and overwrite local ADC reading for ADC3 */
+        if (lis3dh_read_temp(&lis)) {
+            quit("read_temp()", &lis);
+        }
+
         for(k=0; k<fifo.size; k++) {
-            printf("%04.04f %04.04f %04.04f %04.04f\n",
+            printf("x: %04.04f y: %04.04f z: %04.04f mag: %04.04f ADC1:%.1f, ADC2:%.1f, ADC3:%.1f\n",
                 fifo.x[k], fifo.y[k], fifo.z[k],
-                mag(fifo.x[k], fifo.y[k], fifo.z[k]));
+                mag(fifo.x[k], fifo.y[k], fifo.z[k]),
+                lis.adc.adc1, lis.adc.adc2, lis.adc.adc3);
         }
 
     }