Diff: source/Kmx65.h

Revision:

2:06e62a299a74

Parent:

0:ff033dfc838b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/source/Kmx65.h	Thu Mar 14 13:25:02 2019 +0000
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2017-2019 Future Electronics
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef KMX65_H_
+#define KMX65_H_
+
+#include <stdint.h>
+#include <Sensor.h>
+
+
+/** Represents measurement result received from KMX65 accelerometer and magnetometer sensor.
+ * When this matches format of the sensor characteristic then
+ * no conversion is needed.
+ */
+struct Kmx65Value {
+    int16_t     acc_x;
+    int16_t     acc_y;
+    int16_t     acc_z;
+    int16_t     mag_x;
+    int16_t     mag_y;
+    int16_t     mag_z;
+};
+
+
+/** Driver for KMX65 sensor.
+ */
+class Kmx65Driver {
+public:
+    /** Last measurement result status.
+     */
+    enum Status {
+        STATUS_OK = 0,
+        STATUS_STALLED,
+        STATUS_NOT_READY
+    };
+
+    /** KX64 chip register addresses.
+     */
+     enum Register {
+        WHO_AM_I        = 0x00,
+        ODCNTL          = 0x38,
+        CNTL1           = 0x39,
+        CNTL2           = 0x3A,
+        BUF_CTRL1       = 0x77,
+        BUF_CTRL2       = 0x78,
+        BUF_CTRL3       = 0x79,
+        BUF_CLEAR       = 0x7A,
+        BUF_STATUS_1    = 0x7B,
+        BUF_STATUS_2    = 0x7C,
+        BUF_STATUS_3    = 0x7D,
+        BUF_READ        = 0x7E,
+        READ_MASK       = 0x80
+     };
+
+public:
+    /** Create and initialize driver.
+     *
+     * @param bus SPI bus to use
+     * @param cs CS/SS pin to use to select sensor on a bus
+     */
+    Kmx65Driver(SPI& bus, PinName cs);
+
+    /** Obtain reading of the sensor.
+     *
+     * @param[out] value measurement result
+     * @returns operation status
+     */
+    Status read(Kmx65Value& value);
+
+    /** Initialize sensor chip after reset.
+     */
+    void init_chip();
+
+    /** Clear readout buffer.
+     *
+     * Sensor read out is perform via the FIFO buffer included within the chip.
+     * To make sure the readout is synchronized with measurement this buffer
+     * needs to be cleared prior to starting the next measurement cycle.
+     */
+    void clear_buffer();
+
+protected:
+    uint8_t spi_transaction(uint8_t address, uint8_t data);
+    void    spi_read_multiple(uint8_t address, uint8_t *data, uint32_t length);
+
+    SPI&        _spi;
+    DigitalOut  _chip_select;
+    char        _tx_buffer[2];
+    char        _rx_buffer[2];
+};
+
+
+/** KX64 accelerometer/magnetometer sensor interface.
+ */
+class Kmx65Sensor : public Sensor<Kmx65Value> {
+public:
+    /** Create and initialize sensor interface.
+     *
+     * @param spi SPI bus to use
+     * @param cs CS/SS pin to use to select sensor on a bus
+     */
+    Kmx65Sensor(SPI &spi, PinName cs) : _driver(spi, cs) {}
+
+    /** Schedule measurement process.
+     */
+    virtual void start(EventQueue& ev_queue);
+
+protected:
+    void updater();
+
+    Kmx65Driver _driver;
+};
+
+#endif // KX64_H_